src/backend/utils/misc/guc.c

   1 /*--------------------------------------------------------------------
   2  * guc.c
   3  *
   4  * Support for grand unified configuration scheme, including SET
   5  * command, configuration file, and command line options.
   6  * See src/backend/utils/misc/README for more information.
   7  *
   8  *
   9  * Copyright (c) 2000-2009, PostgreSQL Global Development Group
  10  * Written by Peter Eisentraut <peter_e@gmx.net>.
  11  *
  12  * IDENTIFICATION
  13  *        $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.527 2009/12/11 03:34:56 itagaki Exp $
  14  *
  15  *--------------------------------------------------------------------
  16  */
  17 #include "postgres.h"
  18
  19 #include <ctype.h>
  20 #include <float.h>
  21 #include <math.h>
  22 #include <limits.h>
  23 #include <unistd.h>
  24 #include <sys/stat.h>
  25 #ifdef HAVE_SYSLOG
  26 #include <syslog.h>
  27 #endif
  28
  29 #include "access/gin.h"
  30 #include "access/transam.h"
  31 #include "access/twophase.h"
  32 #include "access/xact.h"
  33 #include "catalog/namespace.h"
  34 #include "commands/async.h"
  35 #include "commands/prepare.h"
  36 #include "commands/vacuum.h"
  37 #include "commands/variable.h"
  38 #include "commands/trigger.h"
  39 #include "funcapi.h"
  40 #include "libpq/auth.h"
  41 #include "libpq/be-fsstubs.h"
  42 #include "libpq/pqformat.h"
  43 #include "miscadmin.h"
  44 #include "optimizer/cost.h"
  45 #include "optimizer/geqo.h"
  46 #include "optimizer/paths.h"
  47 #include "optimizer/planmain.h"
  48 #include "parser/parse_expr.h"
  49 #include "parser/parse_type.h"
  50 #include "parser/parser.h"
  51 #include "parser/scansup.h"
  52 #include "pgstat.h"
  53 #include "postmaster/autovacuum.h"
  54 #include "postmaster/bgwriter.h"
  55 #include "postmaster/postmaster.h"
  56 #include "postmaster/syslogger.h"
  57 #include "postmaster/walwriter.h"
  58 #include "storage/bufmgr.h"
  59 #include "storage/fd.h"
  60 #include "tcop/tcopprot.h"
  61 #include "tsearch/ts_cache.h"
  62 #include "utils/builtins.h"
  63 #include "utils/bytea.h"
  64 #include "utils/guc_tables.h"
  65 #include "utils/memutils.h"
  66 #include "utils/pg_locale.h"
  67 #include "utils/plancache.h"
  68 #include "utils/portal.h"
  69 #include "utils/ps_status.h"
  70 #include "utils/tzparser.h"
  71 #include "utils/xml.h"
  72
  73 #ifndef PG_KRB_SRVTAB
  74 #define PG_KRB_SRVTAB ""
  75 #endif
  76 #ifndef PG_KRB_SRVNAM
  77 #define PG_KRB_SRVNAM ""
  78 #endif
  79
  80 #define CONFIG_FILENAME "postgresql.conf"
  81 #define HBA_FILENAME    "pg_hba.conf"
  82 #define IDENT_FILENAME  "pg_ident.conf"
  83
  84 #ifdef EXEC_BACKEND
  85 #define CONFIG_EXEC_PARAMS "global/config_exec_params"
  86 #define CONFIG_EXEC_PARAMS_NEW "global/config_exec_params.new"
  87 #endif
  88
  89 /* upper limit for GUC variables measured in kilobytes of memory */
  90 #if SIZEOF_SIZE_T > 4
  91 #define MAX_KILOBYTES   INT_MAX
  92 #else
  93 #define MAX_KILOBYTES   (INT_MAX / 1024)
  94 #endif
  95
  96 #define KB_PER_MB (1024)
  97 #define KB_PER_GB (1024*1024)
  98
  99 #define MS_PER_S 1000
 100 #define S_PER_MIN 60
 101 #define MS_PER_MIN (1000 * 60)
 102 #define MIN_PER_H 60
 103 #define S_PER_H (60 * 60)
 104 #define MS_PER_H (1000 * 60 * 60)
 105 #define MIN_PER_D (60 * 24)
 106 #define S_PER_D (60 * 60 * 24)
 107 #define MS_PER_D (1000 * 60 * 60 * 24)
 108
 109 /* XXX these should appear in other modules' header files */
 110 extern bool Log_disconnections;
 111 extern int      CommitDelay;
 112 extern int      CommitSiblings;
 113 extern char *default_tablespace;
 114 extern char *temp_tablespaces;
 115 extern bool synchronize_seqscans;
 116 extern bool fullPageWrites;
 117
 118 #ifdef TRACE_SORT
 119 extern bool trace_sort;
 120 #endif
 121 #ifdef TRACE_SYNCSCAN
 122 extern bool trace_syncscan;
 123 #endif
 124 #ifdef DEBUG_BOUNDED_SORT
 125 extern bool optimize_bounded_sort;
 126 #endif
 127
 128 #ifdef USE_SSL
 129 extern char *SSLCipherSuites;
 130 #endif
 131
 132 static void set_config_sourcefile(const char *name, char *sourcefile,
 133                                           int sourceline);
 134
 135 static const char *assign_log_destination(const char *value,
 136                                            bool doit, GucSource source);
 137
 138 #ifdef HAVE_SYSLOG
 139 static int      syslog_facility = LOG_LOCAL0;
 140
 141 static bool assign_syslog_facility(int newval,
 142                                            bool doit, GucSource source);
 143 static const char *assign_syslog_ident(const char *ident,
 144                                         bool doit, GucSource source);
 145 #endif
 146
 147 static bool assign_session_replication_role(int newval, bool doit,
 148                                                                 GucSource source);
 149 static const char *show_num_temp_buffers(void);
 150 static bool assign_phony_autocommit(bool newval, bool doit, GucSource source);
 151 static const char *assign_custom_variable_classes(const char *newval, bool doit,
 152                                                            GucSource source);
 153 static bool assign_debug_assertions(bool newval, bool doit, GucSource source);
 154 static bool assign_bonjour(bool newval, bool doit, GucSource source);
 155 static bool assign_ssl(bool newval, bool doit, GucSource source);
 156 static bool assign_stage_log_stats(bool newval, bool doit, GucSource source);
 157 static bool assign_log_stats(bool newval, bool doit, GucSource source);
 158 static bool assign_transaction_read_only(bool newval, bool doit, GucSource source);
 159 static const char *assign_canonical_path(const char *newval, bool doit, GucSource source);
 160 static const char *assign_timezone_abbreviations(const char *newval, bool doit, GucSource source);
 161 static const char *show_archive_command(void);
 162 static bool assign_tcp_keepalives_idle(int newval, bool doit, GucSource source);
 163 static bool assign_tcp_keepalives_interval(int newval, bool doit, GucSource source);
 164 static bool assign_tcp_keepalives_count(int newval, bool doit, GucSource source);
 165 static const char *show_tcp_keepalives_idle(void);
 166 static const char *show_tcp_keepalives_interval(void);
 167 static const char *show_tcp_keepalives_count(void);
 168 static bool assign_maxconnections(int newval, bool doit, GucSource source);
 169 static bool assign_autovacuum_max_workers(int newval, bool doit, GucSource source);
 170 static bool assign_effective_io_concurrency(int newval, bool doit, GucSource source);
 171 static const char *assign_pgstat_temp_directory(const char *newval, bool doit, GucSource source);
 172 static const char *assign_application_name(const char *newval, bool doit, GucSource source);
 173
 174 static char *config_enum_get_options(struct config_enum * record,
 175                                                 const char *prefix, const char *suffix,
 176                                                 const char *separator);
 177
 178
 179 /*
 180  * Options for enum values defined in this module.
 181  *
 182  * NOTE! Option values may not contain double quotes!
 183  */
 184
 185 static const struct config_enum_entry bytea_output_options[] = {
 186         {"escape", BYTEA_OUTPUT_ESCAPE, false},
 187         {"hex", BYTEA_OUTPUT_HEX, false},
 188         {NULL, 0, false}
 189 };
 190
 191 /*
 192  * We have different sets for client and server message level options because
 193  * they sort slightly different (see "log" level)
 194  */
 195 static const struct config_enum_entry client_message_level_options[] = {
 196         {"debug", DEBUG2, true},
 197         {"debug5", DEBUG5, false},
 198         {"debug4", DEBUG4, false},
 199         {"debug3", DEBUG3, false},
 200         {"debug2", DEBUG2, false},
 201         {"debug1", DEBUG1, false},
 202         {"log", LOG, false},
 203         {"info", INFO, true},
 204         {"notice", NOTICE, false},
 205         {"warning", WARNING, false},
 206         {"error", ERROR, false},
 207         {"fatal", FATAL, true},
 208         {"panic", PANIC, true},
 209         {NULL, 0, false}
 210 };
 211
 212 static const struct config_enum_entry server_message_level_options[] = {
 213         {"debug", DEBUG2, true},
 214         {"debug5", DEBUG5, false},
 215         {"debug4", DEBUG4, false},
 216         {"debug3", DEBUG3, false},
 217         {"debug2", DEBUG2, false},
 218         {"debug1", DEBUG1, false},
 219         {"info", INFO, false},
 220         {"notice", NOTICE, false},
 221         {"warning", WARNING, false},
 222         {"error", ERROR, false},
 223         {"log", LOG, false},
 224         {"fatal", FATAL, false},
 225         {"panic", PANIC, false},
 226         {NULL, 0, false}
 227 };
 228
 229 static const struct config_enum_entry intervalstyle_options[] = {
 230         {"postgres", INTSTYLE_POSTGRES, false},
 231         {"postgres_verbose", INTSTYLE_POSTGRES_VERBOSE, false},
 232         {"sql_standard", INTSTYLE_SQL_STANDARD, false},
 233         {"iso_8601", INTSTYLE_ISO_8601, false},
 234         {NULL, 0, false}
 235 };
 236
 237 static const struct config_enum_entry log_error_verbosity_options[] = {
 238         {"terse", PGERROR_TERSE, false},
 239         {"default", PGERROR_DEFAULT, false},
 240         {"verbose", PGERROR_VERBOSE, false},
 241         {NULL, 0, false}
 242 };
 243
 244 static const struct config_enum_entry log_statement_options[] = {
 245         {"none", LOGSTMT_NONE, false},
 246         {"ddl", LOGSTMT_DDL, false},
 247         {"mod", LOGSTMT_MOD, false},
 248         {"all", LOGSTMT_ALL, false},
 249         {NULL, 0, false}
 250 };
 251
 252 static const struct config_enum_entry isolation_level_options[] = {
 253         {"serializable", XACT_SERIALIZABLE, false},
 254         {"repeatable read", XACT_REPEATABLE_READ, false},
 255         {"read committed", XACT_READ_COMMITTED, false},
 256         {"read uncommitted", XACT_READ_UNCOMMITTED, false},
 257         {NULL, 0}
 258 };
 259
 260 static const struct config_enum_entry session_replication_role_options[] = {
 261         {"origin", SESSION_REPLICATION_ROLE_ORIGIN, false},
 262         {"replica", SESSION_REPLICATION_ROLE_REPLICA, false},
 263         {"local", SESSION_REPLICATION_ROLE_LOCAL, false},
 264         {NULL, 0, false}
 265 };
 266
 267 #ifdef HAVE_SYSLOG
 268 static const struct config_enum_entry syslog_facility_options[] = {
 269         {"local0", LOG_LOCAL0, false},
 270         {"local1", LOG_LOCAL1, false},
 271         {"local2", LOG_LOCAL2, false},
 272         {"local3", LOG_LOCAL3, false},
 273         {"local4", LOG_LOCAL4, false},
 274         {"local5", LOG_LOCAL5, false},
 275         {"local6", LOG_LOCAL6, false},
 276         {"local7", LOG_LOCAL7, false},
 277         {NULL, 0}
 278 };
 279 #endif
 280
 281 static const struct config_enum_entry track_function_options[] = {
 282         {"none", TRACK_FUNC_OFF, false},
 283         {"pl", TRACK_FUNC_PL, false},
 284         {"all", TRACK_FUNC_ALL, false},
 285         {NULL, 0, false}
 286 };
 287
 288 static const struct config_enum_entry xmlbinary_options[] = {
 289         {"base64", XMLBINARY_BASE64, false},
 290         {"hex", XMLBINARY_HEX, false},
 291         {NULL, 0, false}
 292 };
 293
 294 static const struct config_enum_entry xmloption_options[] = {
 295         {"content", XMLOPTION_CONTENT, false},
 296         {"document", XMLOPTION_DOCUMENT, false},
 297         {NULL, 0, false}
 298 };
 299
 300 /*
 301  * Although only "on", "off", and "safe_encoding" are documented, we
 302  * accept all the likely variants of "on" and "off".
 303  */
 304 static const struct config_enum_entry backslash_quote_options[] = {
 305         {"safe_encoding", BACKSLASH_QUOTE_SAFE_ENCODING, false},
 306         {"on", BACKSLASH_QUOTE_ON, false},
 307         {"off", BACKSLASH_QUOTE_OFF, false},
 308         {"true", BACKSLASH_QUOTE_ON, true},
 309         {"false", BACKSLASH_QUOTE_OFF, true},
 310         {"yes", BACKSLASH_QUOTE_ON, true},
 311         {"no", BACKSLASH_QUOTE_OFF, true},
 312         {"1", BACKSLASH_QUOTE_ON, true},
 313         {"0", BACKSLASH_QUOTE_OFF, true},
 314         {NULL, 0, false}
 315 };
 316
 317 /*
 318  * Although only "on", "off", and "partition" are documented, we
 319  * accept all the likely variants of "on" and "off".
 320  */
 321 static const struct config_enum_entry constraint_exclusion_options[] = {
 322         {"partition", CONSTRAINT_EXCLUSION_PARTITION, false},
 323         {"on", CONSTRAINT_EXCLUSION_ON, false},
 324         {"off", CONSTRAINT_EXCLUSION_OFF, false},
 325         {"true", CONSTRAINT_EXCLUSION_ON, true},
 326         {"false", CONSTRAINT_EXCLUSION_OFF, true},
 327         {"yes", CONSTRAINT_EXCLUSION_ON, true},
 328         {"no", CONSTRAINT_EXCLUSION_OFF, true},
 329         {"1", CONSTRAINT_EXCLUSION_ON, true},
 330         {"0", CONSTRAINT_EXCLUSION_OFF, true},
 331         {NULL, 0, false}
 332 };
 333
 334 /*
 335  * Options for enum values stored in other modules
 336  */
 337 extern const struct config_enum_entry sync_method_options[];
 338
 339 /*
 340  * GUC option variables that are exported from this module
 341  */
 342 #ifdef USE_ASSERT_CHECKING
 343 bool            assert_enabled = true;
 344 #else
 345 bool            assert_enabled = false;
 346 #endif
 347 bool            log_duration = false;
 348 bool            Debug_print_plan = false;
 349 bool            Debug_print_parse = false;
 350 bool            Debug_print_rewritten = false;
 351 bool            Debug_pretty_print = true;
 352
 353 bool            log_parser_stats = false;
 354 bool            log_planner_stats = false;
 355 bool            log_executor_stats = false;
 356 bool            log_statement_stats = false;            /* this is sort of all three
 357                                                                                                  * above together */
 358 bool            log_btree_build_stats = false;
 359
 360 bool            check_function_bodies = true;
 361 bool            default_with_oids = false;
 362 bool            SQL_inheritance = true;
 363
 364 bool            Password_encryption = true;
 365
 366 int                     log_min_error_statement = ERROR;
 367 int                     log_min_messages = WARNING;
 368 int                     client_min_messages = NOTICE;
 369 int                     log_min_duration_statement = -1;
 370 int                     log_temp_files = -1;
 371
 372 int                     num_temp_buffers = 1000;
 373
 374 char       *ConfigFileName;
 375 char       *HbaFileName;
 376 char       *IdentFileName;
 377 char       *external_pid_file;
 378
 379 char       *pgstat_temp_directory;
 380
 381 char       *default_do_language;
 382
 383 char       *application_name;
 384
 385 int                     tcp_keepalives_idle;
 386 int                     tcp_keepalives_interval;
 387 int                     tcp_keepalives_count;
 388
 389 /*
 390  * These variables are all dummies that don't do anything, except in some
 391  * cases provide the value for SHOW to display.  The real state is elsewhere
 392  * and is kept in sync by assign_hooks.
 393  */
 394 static char *log_destination_string;
 395
 396 #ifdef HAVE_SYSLOG
 397 static char *syslog_ident_str;
 398 #endif
 399 static bool phony_autocommit;
 400 static bool session_auth_is_superuser;
 401 static double phony_random_seed;
 402 static char *client_encoding_string;
 403 static char *datestyle_string;
 404 static char *locale_collate;
 405 static char *locale_ctype;
 406 static char *server_encoding_string;
 407 static char *server_version_string;
 408 static int      server_version_num;
 409 static char *timezone_string;
 410 static char *log_timezone_string;
 411 static char *timezone_abbreviations_string;
 412 static char *XactIsoLevel_string;
 413 static char *data_directory;
 414 static char *custom_variable_classes;
 415 static int      max_function_args;
 416 static int      max_index_keys;
 417 static int      max_identifier_length;
 418 static int      block_size;
 419 static int      segment_size;
 420 static int      wal_block_size;
 421 static int      wal_segment_size;
 422 static bool integer_datetimes;
 423 static int      effective_io_concurrency;
 424
 425 /* should be static, but commands/variable.c needs to get at these */
 426 char       *role_string;
 427 char       *session_authorization_string;
 428
 429
 430 /*
 431  * Displayable names for context types (enum GucContext)
 432  *
 433  * Note: these strings are deliberately not localized.
 434  */
 435 const char *const GucContext_Names[] =
 436 {
 437          /* PGC_INTERNAL */ "internal",
 438          /* PGC_POSTMASTER */ "postmaster",
 439          /* PGC_SIGHUP */ "sighup",
 440          /* PGC_BACKEND */ "backend",
 441          /* PGC_SUSET */ "superuser",
 442          /* PGC_USERSET */ "user"
 443 };
 444
 445 /*
 446  * Displayable names for source types (enum GucSource)
 447  *
 448  * Note: these strings are deliberately not localized.
 449  */
 450 const char *const GucSource_Names[] =
 451 {
 452          /* PGC_S_DEFAULT */ "default",
 453          /* PGC_S_ENV_VAR */ "environment variable",
 454          /* PGC_S_FILE */ "configuration file",
 455          /* PGC_S_ARGV */ "command line",
 456          /* PGC_S_DATABASE */ "database",
 457          /* PGC_S_USER */ "user",
 458          /* PGC_S_DATABASE_USER */ "database user",
 459          /* PGC_S_CLIENT */ "client",
 460          /* PGC_S_OVERRIDE */ "override",
 461          /* PGC_S_INTERACTIVE */ "interactive",
 462          /* PGC_S_TEST */ "test",
 463          /* PGC_S_SESSION */ "session"
 464 };
 465
 466 /*
 467  * Displayable names for the groupings defined in enum config_group
 468  */
 469 const char *const config_group_names[] =
 470 {
 471         /* UNGROUPED */
 472         gettext_noop("Ungrouped"),
 473         /* FILE_LOCATIONS */
 474         gettext_noop("File Locations"),
 475         /* CONN_AUTH */
 476         gettext_noop("Connections and Authentication"),
 477         /* CONN_AUTH_SETTINGS */
 478         gettext_noop("Connections and Authentication / Connection Settings"),
 479         /* CONN_AUTH_SECURITY */
 480         gettext_noop("Connections and Authentication / Security and Authentication"),
 481         /* RESOURCES */
 482         gettext_noop("Resource Usage"),
 483         /* RESOURCES_MEM */
 484         gettext_noop("Resource Usage / Memory"),
 485         /* RESOURCES_KERNEL */
 486         gettext_noop("Resource Usage / Kernel Resources"),
 487         /* WAL */
 488         gettext_noop("Write-Ahead Log"),
 489         /* WAL_SETTINGS */
 490         gettext_noop("Write-Ahead Log / Settings"),
 491         /* WAL_CHECKPOINTS */
 492         gettext_noop("Write-Ahead Log / Checkpoints"),
 493         /* QUERY_TUNING */
 494         gettext_noop("Query Tuning"),
 495         /* QUERY_TUNING_METHOD */
 496         gettext_noop("Query Tuning / Planner Method Configuration"),
 497         /* QUERY_TUNING_COST */
 498         gettext_noop("Query Tuning / Planner Cost Constants"),
 499         /* QUERY_TUNING_GEQO */
 500         gettext_noop("Query Tuning / Genetic Query Optimizer"),
 501         /* QUERY_TUNING_OTHER */
 502         gettext_noop("Query Tuning / Other Planner Options"),
 503         /* LOGGING */
 504         gettext_noop("Reporting and Logging"),
 505         /* LOGGING_WHERE */
 506         gettext_noop("Reporting and Logging / Where to Log"),
 507         /* LOGGING_WHEN */
 508         gettext_noop("Reporting and Logging / When to Log"),
 509         /* LOGGING_WHAT */
 510         gettext_noop("Reporting and Logging / What to Log"),
 511         /* STATS */
 512         gettext_noop("Statistics"),
 513         /* STATS_MONITORING */
 514         gettext_noop("Statistics / Monitoring"),
 515         /* STATS_COLLECTOR */
 516         gettext_noop("Statistics / Query and Index Statistics Collector"),
 517         /* AUTOVACUUM */
 518         gettext_noop("Autovacuum"),
 519         /* CLIENT_CONN */
 520         gettext_noop("Client Connection Defaults"),
 521         /* CLIENT_CONN_STATEMENT */
 522         gettext_noop("Client Connection Defaults / Statement Behavior"),
 523         /* CLIENT_CONN_LOCALE */
 524         gettext_noop("Client Connection Defaults / Locale and Formatting"),
 525         /* CLIENT_CONN_OTHER */
 526         gettext_noop("Client Connection Defaults / Other Defaults"),
 527         /* LOCK_MANAGEMENT */
 528         gettext_noop("Lock Management"),
 529         /* COMPAT_OPTIONS */
 530         gettext_noop("Version and Platform Compatibility"),
 531         /* COMPAT_OPTIONS_PREVIOUS */
 532         gettext_noop("Version and Platform Compatibility / Previous PostgreSQL Versions"),
 533         /* COMPAT_OPTIONS_CLIENT */
 534         gettext_noop("Version and Platform Compatibility / Other Platforms and Clients"),
 535         /* PRESET_OPTIONS */
 536         gettext_noop("Preset Options"),
 537         /* CUSTOM_OPTIONS */
 538         gettext_noop("Customized Options"),
 539         /* DEVELOPER_OPTIONS */
 540         gettext_noop("Developer Options"),
 541         /* help_config wants this array to be null-terminated */
 542         NULL
 543 };
 544
 545 /*
 546  * Displayable names for GUC variable types (enum config_type)
 547  *
 548  * Note: these strings are deliberately not localized.
 549  */
 550 const char *const config_type_names[] =
 551 {
 552          /* PGC_BOOL */ "bool",
 553          /* PGC_INT */ "integer",
 554          /* PGC_REAL */ "real",
 555          /* PGC_STRING */ "string",
 556          /* PGC_ENUM */ "enum"
 557 };
 558
 559
 560 /*
 561  * Contents of GUC tables
 562  *
 563  * See src/backend/utils/misc/README for design notes.
 564  *
 565  * TO ADD AN OPTION:
 566  *
 567  * 1. Declare a global variable of type bool, int, double, or char*
 568  *        and make use of it.
 569  *
 570  * 2. Decide at what times it's safe to set the option. See guc.h for
 571  *        details.
 572  *
 573  * 3. Decide on a name, a default value, upper and lower bounds (if
 574  *        applicable), etc.
 575  *
 576  * 4. Add a record below.
 577  *
 578  * 5. Add it to src/backend/utils/misc/postgresql.conf.sample, if
 579  *        appropriate.
 580  *
 581  * 6. Don't forget to document the option (at least in config.sgml).
 582  *
 583  * 7. If it's a new GUC_LIST option you must edit pg_dumpall.c to ensure
 584  *        it is not single quoted at dump time.
 585  */
 586
 587
 588 /******** option records follow ********/
 589
 590 static struct config_bool ConfigureNamesBool[] =
 591 {
 592         {
 593                 {"enable_seqscan", PGC_USERSET, QUERY_TUNING_METHOD,
 594                         gettext_noop("Enables the planner's use of sequential-scan plans."),
 595                         NULL
 596                 },
 597                 &enable_seqscan,
 598                 true, NULL, NULL
 599         },
 600         {
 601                 {"enable_indexscan", PGC_USERSET, QUERY_TUNING_METHOD,
 602                         gettext_noop("Enables the planner's use of index-scan plans."),
 603                         NULL
 604                 },
 605                 &enable_indexscan,
 606                 true, NULL, NULL
 607         },
 608         {
 609                 {"enable_bitmapscan", PGC_USERSET, QUERY_TUNING_METHOD,
 610                         gettext_noop("Enables the planner's use of bitmap-scan plans."),
 611                         NULL
 612                 },
 613                 &enable_bitmapscan,
 614                 true, NULL, NULL
 615         },
 616         {
 617                 {"enable_tidscan", PGC_USERSET, QUERY_TUNING_METHOD,
 618                         gettext_noop("Enables the planner's use of TID scan plans."),
 619                         NULL
 620                 },
 621                 &enable_tidscan,
 622                 true, NULL, NULL
 623         },
 624         {
 625                 {"enable_sort", PGC_USERSET, QUERY_TUNING_METHOD,
 626                         gettext_noop("Enables the planner's use of explicit sort steps."),
 627                         NULL
 628                 },
 629                 &enable_sort,
 630                 true, NULL, NULL
 631         },
 632         {
 633                 {"enable_hashagg", PGC_USERSET, QUERY_TUNING_METHOD,
 634                         gettext_noop("Enables the planner's use of hashed aggregation plans."),
 635                         NULL
 636                 },
 637                 &enable_hashagg,
 638                 true, NULL, NULL
 639         },
 640         {
 641                 {"enable_nestloop", PGC_USERSET, QUERY_TUNING_METHOD,
 642                         gettext_noop("Enables the planner's use of nested-loop join plans."),
 643                         NULL
 644                 },
 645                 &enable_nestloop,
 646                 true, NULL, NULL
 647         },
 648         {
 649                 {"enable_mergejoin", PGC_USERSET, QUERY_TUNING_METHOD,
 650                         gettext_noop("Enables the planner's use of merge join plans."),
 651                         NULL
 652                 },
 653                 &enable_mergejoin,
 654                 true, NULL, NULL
 655         },
 656         {
 657                 {"enable_hashjoin", PGC_USERSET, QUERY_TUNING_METHOD,
 658                         gettext_noop("Enables the planner's use of hash join plans."),
 659                         NULL
 660                 },
 661                 &enable_hashjoin,
 662                 true, NULL, NULL
 663         },
 664         {
 665                 {"geqo", PGC_USERSET, QUERY_TUNING_GEQO,
 666                         gettext_noop("Enables genetic query optimization."),
 667                         gettext_noop("This algorithm attempts to do planning without "
 668                                                  "exhaustive searching.")
 669                 },
 670                 &enable_geqo,
 671                 true, NULL, NULL
 672         },
 673         {
 674                 /* Not for general use --- used by SET SESSION AUTHORIZATION */
 675                 {"is_superuser", PGC_INTERNAL, UNGROUPED,
 676                         gettext_noop("Shows whether the current user is a superuser."),
 677                         NULL,
 678                         GUC_REPORT | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
 679                 },
 680                 &session_auth_is_superuser,
 681                 false, NULL, NULL
 682         },
 683         {
 684                 {"bonjour", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
 685                         gettext_noop("Enables advertising the server via Bonjour."),
 686                         NULL
 687                 },
 688                 &enable_bonjour,
 689                 false, assign_bonjour, NULL
 690         },
 691         {
 692                 {"ssl", PGC_POSTMASTER, CONN_AUTH_SECURITY,
 693                         gettext_noop("Enables SSL connections."),
 694                         NULL
 695                 },
 696                 &EnableSSL,
 697                 false, assign_ssl, NULL
 698         },
 699         {
 700                 {"fsync", PGC_SIGHUP, WAL_SETTINGS,
 701                         gettext_noop("Forces synchronization of updates to disk."),
 702                         gettext_noop("The server will use the fsync() system call in several places to make "
 703                         "sure that updates are physically written to disk. This insures "
 704                                                  "that a database cluster will recover to a consistent state after "
 705                                                  "an operating system or hardware crash.")
 706                 },
 707                 &enableFsync,
 708                 true, NULL, NULL
 709         },
 710         {
 711                 {"synchronous_commit", PGC_USERSET, WAL_SETTINGS,
 712                         gettext_noop("Sets immediate fsync at commit."),
 713                         NULL
 714                 },
 715                 &XactSyncCommit,
 716                 true, NULL, NULL
 717         },
 718         {
 719                 {"zero_damaged_pages", PGC_SUSET, DEVELOPER_OPTIONS,
 720                         gettext_noop("Continues processing past damaged page headers."),
 721                         gettext_noop("Detection of a damaged page header normally causes PostgreSQL to "
 722                                 "report an error, aborting the current transaction. Setting "
 723                                                  "zero_damaged_pages to true causes the system to instead report a "
 724                                                  "warning, zero out the damaged page, and continue processing. This "
 725                                                  "behavior will destroy data, namely all the rows on the damaged page."),
 726                         GUC_NOT_IN_SAMPLE
 727                 },
 728                 &zero_damaged_pages,
 729                 false, NULL, NULL
 730         },
 731         {
 732                 {"full_page_writes", PGC_SIGHUP, WAL_SETTINGS,
 733                         gettext_noop("Writes full pages to WAL when first modified after a checkpoint."),
 734                         gettext_noop("A page write in process during an operating system crash might be "
 735                                                  "only partially written to disk.  During recovery, the row changes "
 736                           "stored in WAL are not enough to recover.  This option writes "
 737                                                  "pages when first modified after a checkpoint to WAL so full recovery "
 738                                                  "is possible.")
 739                 },
 740                 &fullPageWrites,
 741                 true, NULL, NULL
 742         },
 743         {
 744                 {"silent_mode", PGC_POSTMASTER, LOGGING_WHERE,
 745                         gettext_noop("Runs the server silently."),
 746                         gettext_noop("If this parameter is set, the server will automatically run in the "
 747                                  "background and any controlling terminals are dissociated.")
 748                 },
 749                 &SilentMode,
 750                 false, NULL, NULL
 751         },
 752         {
 753                 {"log_checkpoints", PGC_SIGHUP, LOGGING_WHAT,
 754                         gettext_noop("Logs each checkpoint."),
 755                         NULL
 756                 },
 757                 &log_checkpoints,
 758                 false, NULL, NULL
 759         },
 760         {
 761                 {"log_connections", PGC_BACKEND, LOGGING_WHAT,
 762                         gettext_noop("Logs each successful connection."),
 763                         NULL
 764                 },
 765                 &Log_connections,
 766                 false, NULL, NULL
 767         },
 768         {
 769                 {"log_disconnections", PGC_BACKEND, LOGGING_WHAT,
 770                         gettext_noop("Logs end of a session, including duration."),
 771                         NULL
 772                 },
 773                 &Log_disconnections,
 774                 false, NULL, NULL
 775         },
 776         {
 777                 {"debug_assertions", PGC_USERSET, DEVELOPER_OPTIONS,
 778                         gettext_noop("Turns on various assertion checks."),
 779                         gettext_noop("This is a debugging aid."),
 780                         GUC_NOT_IN_SAMPLE
 781                 },
 782                 &assert_enabled,
 783 #ifdef USE_ASSERT_CHECKING
 784                 true,
 785 #else
 786                 false,
 787 #endif
 788                 assign_debug_assertions, NULL
 789         },
 790         {
 791                 /* currently undocumented, so don't show in SHOW ALL */
 792                 {"exit_on_error", PGC_USERSET, UNGROUPED,
 793                         gettext_noop("No description available."),
 794                         NULL,
 795                         GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE
 796                 },
 797                 &ExitOnAnyError,
 798                 false, NULL, NULL
 799         },
 800         {
 801                 {"log_duration", PGC_SUSET, LOGGING_WHAT,
 802                         gettext_noop("Logs the duration of each completed SQL statement."),
 803                         NULL
 804                 },
 805                 &log_duration,
 806                 false, NULL, NULL
 807         },
 808         {
 809                 {"debug_print_parse", PGC_USERSET, LOGGING_WHAT,
 810                         gettext_noop("Logs each query's parse tree."),
 811                         NULL
 812                 },
 813                 &Debug_print_parse,
 814                 false, NULL, NULL
 815         },
 816         {
 817                 {"debug_print_rewritten", PGC_USERSET, LOGGING_WHAT,
 818                         gettext_noop("Logs each query's rewritten parse tree."),
 819                         NULL
 820                 },
 821                 &Debug_print_rewritten,
 822                 false, NULL, NULL
 823         },
 824         {
 825                 {"debug_print_plan", PGC_USERSET, LOGGING_WHAT,
 826                         gettext_noop("Logs each query's execution plan."),
 827                         NULL
 828                 },
 829                 &Debug_print_plan,
 830                 false, NULL, NULL
 831         },
 832         {
 833                 {"debug_pretty_print", PGC_USERSET, LOGGING_WHAT,
 834                         gettext_noop("Indents parse and plan tree displays."),
 835                         NULL
 836                 },
 837                 &Debug_pretty_print,
 838                 true, NULL, NULL
 839         },
 840         {
 841                 {"log_parser_stats", PGC_SUSET, STATS_MONITORING,
 842                         gettext_noop("Writes parser performance statistics to the server log."),
 843                         NULL
 844                 },
 845                 &log_parser_stats,
 846                 false, assign_stage_log_stats, NULL
 847         },
 848         {
 849                 {"log_planner_stats", PGC_SUSET, STATS_MONITORING,
 850                         gettext_noop("Writes planner performance statistics to the server log."),
 851                         NULL
 852                 },
 853                 &log_planner_stats,
 854                 false, assign_stage_log_stats, NULL
 855         },
 856         {
 857                 {"log_executor_stats", PGC_SUSET, STATS_MONITORING,
 858                         gettext_noop("Writes executor performance statistics to the server log."),
 859                         NULL
 860                 },
 861                 &log_executor_stats,
 862                 false, assign_stage_log_stats, NULL
 863         },
 864         {
 865                 {"log_statement_stats", PGC_SUSET, STATS_MONITORING,
 866                         gettext_noop("Writes cumulative performance statistics to the server log."),
 867                         NULL
 868                 },
 869                 &log_statement_stats,
 870                 false, assign_log_stats, NULL
 871         },
 872 #ifdef BTREE_BUILD_STATS
 873         {
 874                 {"log_btree_build_stats", PGC_SUSET, DEVELOPER_OPTIONS,
 875                         gettext_noop("No description available."),
 876                         NULL,
 877                         GUC_NOT_IN_SAMPLE
 878                 },
 879                 &log_btree_build_stats,
 880                 false, NULL, NULL
 881         },
 882 #endif
 883
 884         {
 885                 {"track_activities", PGC_SUSET, STATS_COLLECTOR,
 886                         gettext_noop("Collects information about executing commands."),
 887                         gettext_noop("Enables the collection of information on the currently "
 888                                                  "executing command of each session, along with "
 889                                                  "the time at which that command began execution.")
 890                 },
 891                 &pgstat_track_activities,
 892                 true, NULL, NULL
 893         },
 894         {
 895                 {"track_counts", PGC_SUSET, STATS_COLLECTOR,
 896                         gettext_noop("Collects statistics on database activity."),
 897                         NULL
 898                 },
 899                 &pgstat_track_counts,
 900                 true, NULL, NULL
 901         },
 902
 903         {
 904                 {"update_process_title", PGC_SUSET, STATS_COLLECTOR,
 905                         gettext_noop("Updates the process title to show the active SQL command."),
 906                         gettext_noop("Enables updating of the process title every time a new SQL command is received by the server.")
 907                 },
 908                 &update_process_title,
 909                 true, NULL, NULL
 910         },
 911
 912         {
 913                 {"autovacuum", PGC_SIGHUP, AUTOVACUUM,
 914                         gettext_noop("Starts the autovacuum subprocess."),
 915                         NULL
 916                 },
 917                 &autovacuum_start_daemon,
 918                 true, NULL, NULL
 919         },
 920
 921         {
 922                 {"trace_notify", PGC_USERSET, DEVELOPER_OPTIONS,
 923                         gettext_noop("Generates debugging output for LISTEN and NOTIFY."),
 924                         NULL,
 925                         GUC_NOT_IN_SAMPLE
 926                 },
 927                 &Trace_notify,
 928                 false, NULL, NULL
 929         },
 930
 931 #ifdef LOCK_DEBUG
 932         {
 933                 {"trace_locks", PGC_SUSET, DEVELOPER_OPTIONS,
 934                         gettext_noop("No description available."),
 935                         NULL,
 936                         GUC_NOT_IN_SAMPLE
 937                 },
 938                 &Trace_locks,
 939                 false, NULL, NULL
 940         },
 941         {
 942                 {"trace_userlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 943                         gettext_noop("No description available."),
 944                         NULL,
 945                         GUC_NOT_IN_SAMPLE
 946                 },
 947                 &Trace_userlocks,
 948                 false, NULL, NULL
 949         },
 950         {
 951                 {"trace_lwlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 952                         gettext_noop("No description available."),
 953                         NULL,
 954                         GUC_NOT_IN_SAMPLE
 955                 },
 956                 &Trace_lwlocks,
 957                 false, NULL, NULL
 958         },
 959         {
 960                 {"debug_deadlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 961                         gettext_noop("No description available."),
 962                         NULL,
 963                         GUC_NOT_IN_SAMPLE
 964                 },
 965                 &Debug_deadlocks,
 966                 false, NULL, NULL
 967         },
 968 #endif
 969
 970         {
 971                 {"log_lock_waits", PGC_SUSET, LOGGING_WHAT,
 972                         gettext_noop("Logs long lock waits."),
 973                         NULL
 974                 },
 975                 &log_lock_waits,
 976                 false, NULL, NULL
 977         },
 978
 979         {
 980                 {"log_hostname", PGC_SIGHUP, LOGGING_WHAT,
 981                         gettext_noop("Logs the host name in the connection logs."),
 982                         gettext_noop("By default, connection logs only show the IP address "
 983                                                  "of the connecting host. If you want them to show the host name you "
 984                           "can turn this on, but depending on your host name resolution "
 985                            "setup it might impose a non-negligible performance penalty.")
 986                 },
 987                 &log_hostname,
 988                 false, NULL, NULL
 989         },
 990         {
 991                 {"sql_inheritance", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
 992                         gettext_noop("Causes subtables to be included by default in various commands."),
 993                         NULL
 994                 },
 995                 &SQL_inheritance,
 996                 true, NULL, NULL
 997         },
 998         {
 999                 {"password_encryption", PGC_USERSET, CONN_AUTH_SECURITY,
1000                         gettext_noop("Encrypt passwords."),
1001                         gettext_noop("When a password is specified in CREATE USER or "
1002                            "ALTER USER without writing either ENCRYPTED or UNENCRYPTED, "
1003                                                  "this parameter determines whether the password is to be encrypted.")
1004                 },
1005                 &Password_encryption,
1006                 true, NULL, NULL
1007         },
1008         {
1009                 {"transform_null_equals", PGC_USERSET, COMPAT_OPTIONS_CLIENT,
1010                         gettext_noop("Treats \"expr=NULL\" as \"expr IS NULL\"."),
1011                         gettext_noop("When turned on, expressions of the form expr = NULL "
1012                            "(or NULL = expr) are treated as expr IS NULL, that is, they "
1013                                 "return true if expr evaluates to the null value, and false "
1014                            "otherwise. The correct behavior of expr = NULL is to always "
1015                                                  "return null (unknown).")
1016                 },
1017                 &Transform_null_equals,
1018                 false, NULL, NULL
1019         },
1020         {
1021                 {"db_user_namespace", PGC_SIGHUP, CONN_AUTH_SECURITY,
1022                         gettext_noop("Enables per-database user names."),
1023                         NULL
1024                 },
1025                 &Db_user_namespace,
1026                 false, NULL, NULL
1027         },
1028         {
1029                 /* only here for backwards compatibility */
1030                 {"autocommit", PGC_USERSET, CLIENT_CONN_STATEMENT,
1031                         gettext_noop("This parameter doesn't do anything."),
1032                         gettext_noop("It's just here so that we won't choke on SET AUTOCOMMIT TO ON from 7.3-vintage clients."),
1033                         GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE
1034                 },
1035                 &phony_autocommit,
1036                 true, assign_phony_autocommit, NULL
1037         },
1038         {
1039                 {"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
1040                         gettext_noop("Sets the default read-only status of new transactions."),
1041                         NULL
1042                 },
1043                 &DefaultXactReadOnly,
1044                 false, NULL, NULL
1045         },
1046         {
1047                 {"transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
1048                         gettext_noop("Sets the current transaction's read-only status."),
1049                         NULL,
1050                         GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1051                 },
1052                 &XactReadOnly,
1053                 false, assign_transaction_read_only, NULL
1054         },
1055         {
1056                 {"check_function_bodies", PGC_USERSET, CLIENT_CONN_STATEMENT,
1057                         gettext_noop("Check function bodies during CREATE FUNCTION."),
1058                         NULL
1059                 },
1060                 &check_function_bodies,
1061                 true, NULL, NULL
1062         },
1063         {
1064                 {"array_nulls", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1065                         gettext_noop("Enable input of NULL elements in arrays."),
1066                         gettext_noop("When turned on, unquoted NULL in an array input "
1067                                                  "value means a null value; "
1068                                                  "otherwise it is taken literally.")
1069                 },
1070                 &Array_nulls,
1071                 true, NULL, NULL
1072         },
1073         {
1074                 {"default_with_oids", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1075                         gettext_noop("Create new tables with OIDs by default."),
1076                         NULL
1077                 },
1078                 &default_with_oids,
1079                 false, NULL, NULL
1080         },
1081         {
1082                 {"logging_collector", PGC_POSTMASTER, LOGGING_WHERE,
1083                         gettext_noop("Start a subprocess to capture stderr output and/or csvlogs into log files."),
1084                         NULL
1085                 },
1086                 &Logging_collector,
1087                 false, NULL, NULL
1088         },
1089         {
1090                 {"log_truncate_on_rotation", PGC_SIGHUP, LOGGING_WHERE,
1091                         gettext_noop("Truncate existing log files of same name during log rotation."),
1092                         NULL
1093                 },
1094                 &Log_truncate_on_rotation,
1095                 false, NULL, NULL
1096         },
1097
1098 #ifdef TRACE_SORT
1099         {
1100                 {"trace_sort", PGC_USERSET, DEVELOPER_OPTIONS,
1101                         gettext_noop("Emit information about resource usage in sorting."),
1102                         NULL,
1103                         GUC_NOT_IN_SAMPLE
1104                 },
1105                 &trace_sort,
1106                 false, NULL, NULL
1107         },
1108 #endif
1109
1110 #ifdef TRACE_SYNCSCAN
1111         /* this is undocumented because not exposed in a standard build */
1112         {
1113                 {"trace_syncscan", PGC_USERSET, DEVELOPER_OPTIONS,
1114                         gettext_noop("Generate debugging output for synchronized scanning."),
1115                         NULL,
1116                         GUC_NOT_IN_SAMPLE
1117                 },
1118                 &trace_syncscan,
1119                 false, NULL, NULL
1120         },
1121 #endif
1122
1123 #ifdef DEBUG_BOUNDED_SORT
1124         /* this is undocumented because not exposed in a standard build */
1125         {
1126                 {
1127                         "optimize_bounded_sort", PGC_USERSET, QUERY_TUNING_METHOD,
1128                         gettext_noop("Enable bounded sorting using heap sort."),
1129                         NULL,
1130                         GUC_NOT_IN_SAMPLE
1131                 },
1132                 &optimize_bounded_sort,
1133                 true, NULL, NULL
1134         },
1135 #endif
1136
1137 #ifdef WAL_DEBUG
1138         {
1139                 {"wal_debug", PGC_SUSET, DEVELOPER_OPTIONS,
1140                         gettext_noop("Emit WAL-related debugging output."),
1141                         NULL,
1142                         GUC_NOT_IN_SAMPLE
1143                 },
1144                 &XLOG_DEBUG,
1145                 false, NULL, NULL
1146         },
1147 #endif
1148
1149         {
1150                 {"integer_datetimes", PGC_INTERNAL, PRESET_OPTIONS,
1151                         gettext_noop("Datetimes are integer based."),
1152                         NULL,
1153                         GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1154                 },
1155                 &integer_datetimes,
1156 #ifdef HAVE_INT64_TIMESTAMP
1157                 true, NULL, NULL
1158 #else
1159                 false, NULL, NULL
1160 #endif
1161         },
1162
1163         {
1164                 {"krb_caseins_users", PGC_SIGHUP, CONN_AUTH_SECURITY,
1165                         gettext_noop("Sets whether Kerberos and GSSAPI user names should be treated as case-insensitive."),
1166                         NULL
1167                 },
1168                 &pg_krb_caseins_users,
1169                 false, NULL, NULL
1170         },
1171
1172         {
1173                 {"escape_string_warning", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1174                         gettext_noop("Warn about backslash escapes in ordinary string literals."),
1175                         NULL
1176                 },
1177                 &escape_string_warning,
1178                 true, NULL, NULL
1179         },
1180
1181         {
1182                 {"standard_conforming_strings", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1183                         gettext_noop("Causes '...' strings to treat backslashes literally."),
1184                         NULL,
1185                         GUC_REPORT
1186                 },
1187                 &standard_conforming_strings,
1188                 false, NULL, NULL
1189         },
1190
1191         {
1192                 {"synchronize_seqscans", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1193                         gettext_noop("Enable synchronized sequential scans."),
1194                         NULL
1195                 },
1196                 &synchronize_seqscans,
1197                 true, NULL, NULL
1198         },
1199
1200         {
1201                 {"archive_mode", PGC_POSTMASTER, WAL_SETTINGS,
1202                         gettext_noop("Allows archiving of WAL files using archive_command."),
1203                         NULL
1204                 },
1205                 &XLogArchiveMode,
1206                 false, NULL, NULL
1207         },
1208
1209         {
1210                 {"allow_system_table_mods", PGC_POSTMASTER, DEVELOPER_OPTIONS,
1211                         gettext_noop("Allows modifications of the structure of system tables."),
1212                         NULL,
1213                         GUC_NOT_IN_SAMPLE
1214                 },
1215                 &allowSystemTableMods,
1216                 false, NULL, NULL
1217         },
1218
1219         {
1220                 {"ignore_system_indexes", PGC_BACKEND, DEVELOPER_OPTIONS,
1221                         gettext_noop("Disables reading from system indexes."),
1222                         gettext_noop("It does not prevent updating the indexes, so it is safe "
1223                                                  "to use.  The worst consequence is slowness."),
1224                         GUC_NOT_IN_SAMPLE
1225                 },
1226                 &IgnoreSystemIndexes,
1227                 false, NULL, NULL
1228         },
1229
1230         {
1231                 {"lo_compat_privileges", PGC_SUSET, COMPAT_OPTIONS_PREVIOUS,
1232                         gettext_noop("Enables backward compatibility in privilege checks on large objects"),
1233                         gettext_noop("When turned on, privilege checks on large objects perform "
1234                                                  "with backward compatibility as 8.4.x or earlier releases.")
1235                 },
1236                 &lo_compat_privileges,
1237                 false, NULL, NULL
1238         },
1239
1240         /* End-of-list marker */
1241         {
1242                 {NULL, 0, 0, NULL, NULL}, NULL, false, NULL, NULL
1243         }
1244 };
1245
1246
1247 static struct config_int ConfigureNamesInt[] =
1248 {
1249         {
1250                 {"archive_timeout", PGC_SIGHUP, WAL_SETTINGS,
1251                         gettext_noop("Forces a switch to the next xlog file if a "
1252                                                  "new file has not been started within N seconds."),
1253                         NULL,
1254                         GUC_UNIT_S
1255                 },
1256                 &XLogArchiveTimeout,
1257                 0, 0, INT_MAX, NULL, NULL
1258         },
1259         {
1260                 {"post_auth_delay", PGC_BACKEND, DEVELOPER_OPTIONS,
1261                         gettext_noop("Waits N seconds on connection startup after authentication."),
1262                         gettext_noop("This allows attaching a debugger to the process."),
1263                         GUC_NOT_IN_SAMPLE | GUC_UNIT_S
1264                 },
1265                 &PostAuthDelay,
1266                 0, 0, INT_MAX, NULL, NULL
1267         },
1268         {
1269                 {"default_statistics_target", PGC_USERSET, QUERY_TUNING_OTHER,
1270                         gettext_noop("Sets the default statistics target."),
1271                         gettext_noop("This applies to table columns that have not had a "
1272                                 "column-specific target set via ALTER TABLE SET STATISTICS.")
1273                 },
1274                 &default_statistics_target,
1275                 100, 1, 10000, NULL, NULL
1276         },
1277         {
1278                 {"from_collapse_limit", PGC_USERSET, QUERY_TUNING_OTHER,
1279                         gettext_noop("Sets the FROM-list size beyond which subqueries "
1280                                                  "are not collapsed."),
1281                         gettext_noop("The planner will merge subqueries into upper "
1282                                 "queries if the resulting FROM list would have no more than "
1283                                                  "this many items.")
1284                 },
1285                 &from_collapse_limit,
1286                 8, 1, INT_MAX, NULL, NULL
1287         },
1288         {
1289                 {"join_collapse_limit", PGC_USERSET, QUERY_TUNING_OTHER,
1290                         gettext_noop("Sets the FROM-list size beyond which JOIN "
1291                                                  "constructs are not flattened."),
1292                         gettext_noop("The planner will flatten explicit JOIN "
1293                                                  "constructs into lists of FROM items whenever a "
1294                                                  "list of no more than this many items would result.")
1295                 },
1296                 &join_collapse_limit,
1297                 8, 1, INT_MAX, NULL, NULL
1298         },
1299         {
1300                 {"geqo_threshold", PGC_USERSET, QUERY_TUNING_GEQO,
1301                         gettext_noop("Sets the threshold of FROM items beyond which GEQO is used."),
1302                         NULL
1303                 },
1304                 &geqo_threshold,
1305                 12, 2, INT_MAX, NULL, NULL
1306         },
1307         {
1308                 {"geqo_effort", PGC_USERSET, QUERY_TUNING_GEQO,
1309                         gettext_noop("GEQO: effort is used to set the default for other GEQO parameters."),
1310                         NULL
1311                 },
1312                 &Geqo_effort,
1313                 DEFAULT_GEQO_EFFORT, MIN_GEQO_EFFORT, MAX_GEQO_EFFORT, NULL, NULL
1314         },
1315         {
1316                 {"geqo_pool_size", PGC_USERSET, QUERY_TUNING_GEQO,
1317                         gettext_noop("GEQO: number of individuals in the population."),
1318                         gettext_noop("Zero selects a suitable default value.")
1319                 },
1320                 &Geqo_pool_size,
1321                 0, 0, INT_MAX, NULL, NULL
1322         },
1323         {
1324                 {"geqo_generations", PGC_USERSET, QUERY_TUNING_GEQO,
1325                         gettext_noop("GEQO: number of iterations of the algorithm."),
1326                         gettext_noop("Zero selects a suitable default value.")
1327                 },
1328                 &Geqo_generations,
1329                 0, 0, INT_MAX, NULL, NULL
1330         },
1331
1332         {
1333                 /* This is PGC_SIGHUP so all backends have the same value. */
1334                 {"deadlock_timeout", PGC_SIGHUP, LOCK_MANAGEMENT,
1335                         gettext_noop("Sets the time to wait on a lock before checking for deadlock."),
1336                         NULL,
1337                         GUC_UNIT_MS
1338                 },
1339                 &DeadlockTimeout,
1340                 1000, 1, INT_MAX / 1000, NULL, NULL
1341         },
1342
1343         /*
1344          * Note: MaxBackends is limited to INT_MAX/4 because some places compute
1345          * 4*MaxBackends without any overflow check.  This check is made in
1346          * assign_maxconnections, since MaxBackends is computed as MaxConnections
1347          * plus autovacuum_max_workers plus one (for the autovacuum launcher).
1348          *
1349          * Likewise we have to limit NBuffers to INT_MAX/2.
1350          */
1351         {
1352                 {"max_connections", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1353                         gettext_noop("Sets the maximum number of concurrent connections."),
1354                         NULL
1355                 },
1356                 &MaxConnections,
1357                 100, 1, INT_MAX / 4, assign_maxconnections, NULL
1358         },
1359
1360         {
1361                 {"superuser_reserved_connections", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1362                         gettext_noop("Sets the number of connection slots reserved for superusers."),
1363                         NULL
1364                 },
1365                 &ReservedBackends,
1366                 3, 0, INT_MAX / 4, NULL, NULL
1367         },
1368
1369         {
1370                 {"shared_buffers", PGC_POSTMASTER, RESOURCES_MEM,
1371                         gettext_noop("Sets the number of shared memory buffers used by the server."),
1372                         NULL,
1373                         GUC_UNIT_BLOCKS
1374                 },
1375                 &NBuffers,
1376                 1024, 16, INT_MAX / 2, NULL, NULL
1377         },
1378
1379         {
1380                 {"temp_buffers", PGC_USERSET, RESOURCES_MEM,
1381                         gettext_noop("Sets the maximum number of temporary buffers used by each session."),
1382                         NULL,
1383                         GUC_UNIT_BLOCKS
1384                 },
1385                 &num_temp_buffers,
1386                 1024, 100, INT_MAX / 2, NULL, show_num_temp_buffers
1387         },
1388
1389         {
1390                 {"port", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1391                         gettext_noop("Sets the TCP port the server listens on."),
1392                         NULL
1393                 },
1394                 &PostPortNumber,
1395                 DEF_PGPORT, 1, 65535, NULL, NULL
1396         },
1397
1398         {
1399                 {"unix_socket_permissions", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1400                         gettext_noop("Sets the access permissions of the Unix-domain socket."),
1401                         gettext_noop("Unix-domain sockets use the usual Unix file system "
1402                                                  "permission set. The parameter value is expected to be a numeric mode "
1403                                                  "specification in the form accepted by the chmod and umask system "
1404                                                  "calls. (To use the customary octal format the number must start with "
1405                                                  "a 0 (zero).)")
1406                 },
1407                 &Unix_socket_permissions,
1408                 0777, 0000, 0777, NULL, NULL
1409         },
1410
1411         {
1412                 {"work_mem", PGC_USERSET, RESOURCES_MEM,
1413                         gettext_noop("Sets the maximum memory to be used for query workspaces."),
1414                         gettext_noop("This much memory can be used by each internal "
1415                                                  "sort operation and hash table before switching to "
1416                                                  "temporary disk files."),
1417                         GUC_UNIT_KB
1418                 },
1419                 &work_mem,
1420                 1024, 64, MAX_KILOBYTES, NULL, NULL
1421         },
1422
1423         {
1424                 {"maintenance_work_mem", PGC_USERSET, RESOURCES_MEM,
1425                         gettext_noop("Sets the maximum memory to be used for maintenance operations."),
1426                         gettext_noop("This includes operations such as VACUUM and CREATE INDEX."),
1427                         GUC_UNIT_KB
1428                 },
1429                 &maintenance_work_mem,
1430                 16384, 1024, MAX_KILOBYTES, NULL, NULL
1431         },
1432
1433         {
1434                 {"max_stack_depth", PGC_SUSET, RESOURCES_MEM,
1435                         gettext_noop("Sets the maximum stack depth, in kilobytes."),
1436                         NULL,
1437                         GUC_UNIT_KB
1438                 },
1439                 &max_stack_depth,
1440                 100, 100, MAX_KILOBYTES, assign_max_stack_depth, NULL
1441         },
1442
1443         {
1444                 {"vacuum_cost_page_hit", PGC_USERSET, RESOURCES,
1445                         gettext_noop("Vacuum cost for a page found in the buffer cache."),
1446                         NULL
1447                 },
1448                 &VacuumCostPageHit,
1449                 1, 0, 10000, NULL, NULL
1450         },
1451
1452         {
1453                 {"vacuum_cost_page_miss", PGC_USERSET, RESOURCES,
1454                         gettext_noop("Vacuum cost for a page not found in the buffer cache."),
1455                         NULL
1456                 },
1457                 &VacuumCostPageMiss,
1458                 10, 0, 10000, NULL, NULL
1459         },
1460
1461         {
1462                 {"vacuum_cost_page_dirty", PGC_USERSET, RESOURCES,
1463                         gettext_noop("Vacuum cost for a page dirtied by vacuum."),
1464                         NULL
1465                 },
1466                 &VacuumCostPageDirty,
1467                 20, 0, 10000, NULL, NULL
1468         },
1469
1470         {
1471                 {"vacuum_cost_limit", PGC_USERSET, RESOURCES,
1472                         gettext_noop("Vacuum cost amount available before napping."),
1473                         NULL
1474                 },
1475                 &VacuumCostLimit,
1476                 200, 1, 10000, NULL, NULL
1477         },
1478
1479         {
1480                 {"vacuum_cost_delay", PGC_USERSET, RESOURCES,
1481                         gettext_noop("Vacuum cost delay in milliseconds."),
1482                         NULL,
1483                         GUC_UNIT_MS
1484                 },
1485                 &VacuumCostDelay,
1486                 0, 0, 100, NULL, NULL
1487         },
1488
1489         {
1490                 {"autovacuum_vacuum_cost_delay", PGC_SIGHUP, AUTOVACUUM,
1491                         gettext_noop("Vacuum cost delay in milliseconds, for autovacuum."),
1492                         NULL,
1493                         GUC_UNIT_MS
1494                 },
1495                 &autovacuum_vac_cost_delay,
1496                 20, -1, 100, NULL, NULL
1497         },
1498
1499         {
1500                 {"autovacuum_vacuum_cost_limit", PGC_SIGHUP, AUTOVACUUM,
1501                         gettext_noop("Vacuum cost amount available before napping, for autovacuum."),
1502                         NULL
1503                 },
1504                 &autovacuum_vac_cost_limit,
1505                 -1, -1, 10000, NULL, NULL
1506         },
1507
1508         {
1509                 {"max_files_per_process", PGC_POSTMASTER, RESOURCES_KERNEL,
1510                         gettext_noop("Sets the maximum number of simultaneously open files for each server process."),
1511                         NULL
1512                 },
1513                 &max_files_per_process,
1514                 1000, 25, INT_MAX, NULL, NULL
1515         },
1516
1517         {
1518                 {"max_prepared_transactions", PGC_POSTMASTER, RESOURCES,
1519                         gettext_noop("Sets the maximum number of simultaneously prepared transactions."),
1520                         NULL
1521                 },
1522                 &max_prepared_xacts,
1523                 0, 0, INT_MAX / 4, NULL, NULL
1524         },
1525
1526 #ifdef LOCK_DEBUG
1527         {
1528                 {"trace_lock_oidmin", PGC_SUSET, DEVELOPER_OPTIONS,
1529                         gettext_noop("No description available."),
1530                         NULL,
1531                         GUC_NOT_IN_SAMPLE
1532                 },
1533                 &Trace_lock_oidmin,
1534                 FirstNormalObjectId, 0, INT_MAX, NULL, NULL
1535         },
1536         {
1537                 {"trace_lock_table", PGC_SUSET, DEVELOPER_OPTIONS,
1538                         gettext_noop("No description available."),
1539                         NULL,
1540                         GUC_NOT_IN_SAMPLE
1541                 },
1542                 &Trace_lock_table,
1543                 0, 0, INT_MAX, NULL, NULL
1544         },
1545 #endif
1546
1547         {
1548                 {"statement_timeout", PGC_USERSET, CLIENT_CONN_STATEMENT,
1549                         gettext_noop("Sets the maximum allowed duration of any statement."),
1550                         gettext_noop("A value of 0 turns off the timeout."),
1551                         GUC_UNIT_MS
1552                 },
1553                 &StatementTimeout,
1554                 0, 0, INT_MAX, NULL, NULL
1555         },
1556
1557         {
1558                 {"vacuum_freeze_min_age", PGC_USERSET, CLIENT_CONN_STATEMENT,
1559                         gettext_noop("Minimum age at which VACUUM should freeze a table row."),
1560                         NULL
1561                 },
1562                 &vacuum_freeze_min_age,
1563                 50000000, 0, 1000000000, NULL, NULL
1564         },
1565
1566         {
1567                 {"vacuum_freeze_table_age", PGC_USERSET, CLIENT_CONN_STATEMENT,
1568                         gettext_noop("Age at which VACUUM should scan whole table to freeze tuples."),
1569                         NULL
1570                 },
1571                 &vacuum_freeze_table_age,
1572                 150000000, 0, 2000000000, NULL, NULL
1573         },
1574
1575         {
1576                 {"max_locks_per_transaction", PGC_POSTMASTER, LOCK_MANAGEMENT,
1577                         gettext_noop("Sets the maximum number of locks per transaction."),
1578                         gettext_noop("The shared lock table is sized on the assumption that "
1579                           "at most max_locks_per_transaction * max_connections distinct "
1580                                                  "objects will need to be locked at any one time.")
1581                 },
1582                 &max_locks_per_xact,
1583                 64, 10, INT_MAX, NULL, NULL
1584         },
1585
1586         {
1587                 {"authentication_timeout", PGC_SIGHUP, CONN_AUTH_SECURITY,
1588                         gettext_noop("Sets the maximum allowed time to complete client authentication."),
1589                         NULL,
1590                         GUC_UNIT_S
1591                 },
1592                 &AuthenticationTimeout,
1593                 60, 1, 600, NULL, NULL
1594         },
1595
1596         {
1597                 /* Not for general use */
1598                 {"pre_auth_delay", PGC_SIGHUP, DEVELOPER_OPTIONS,
1599                         gettext_noop("Waits N seconds on connection startup before authentication."),
1600                         gettext_noop("This allows attaching a debugger to the process."),
1601                         GUC_NOT_IN_SAMPLE | GUC_UNIT_S
1602                 },
1603                 &PreAuthDelay,
1604                 0, 0, 60, NULL, NULL
1605         },
1606
1607         {
1608                 {"checkpoint_segments", PGC_SIGHUP, WAL_CHECKPOINTS,
1609                         gettext_noop("Sets the maximum distance in log segments between automatic WAL checkpoints."),
1610                         NULL
1611                 },
1612                 &CheckPointSegments,
1613                 3, 1, INT_MAX, NULL, NULL
1614         },
1615
1616         {
1617                 {"checkpoint_timeout", PGC_SIGHUP, WAL_CHECKPOINTS,
1618                         gettext_noop("Sets the maximum time between automatic WAL checkpoints."),
1619                         NULL,
1620                         GUC_UNIT_S
1621                 },
1622                 &CheckPointTimeout,
1623                 300, 30, 3600, NULL, NULL
1624         },
1625
1626         {
1627                 {"checkpoint_warning", PGC_SIGHUP, WAL_CHECKPOINTS,
1628                         gettext_noop("Enables warnings if checkpoint segments are filled more "
1629                                                  "frequently than this."),
1630                         gettext_noop("Write a message to the server log if checkpoints "
1631                         "caused by the filling of checkpoint segment files happens more "
1632                                                  "frequently than this number of seconds. Zero turns off the warning."),
1633                         GUC_UNIT_S
1634                 },
1635                 &CheckPointWarning,
1636                 30, 0, INT_MAX, NULL, NULL
1637         },
1638
1639         {
1640                 {"wal_buffers", PGC_POSTMASTER, WAL_SETTINGS,
1641                         gettext_noop("Sets the number of disk-page buffers in shared memory for WAL."),
1642                         NULL,
1643                         GUC_UNIT_XBLOCKS
1644                 },
1645                 &XLOGbuffers,
1646                 8, 4, INT_MAX, NULL, NULL
1647         },
1648
1649         {
1650                 {"wal_writer_delay", PGC_SIGHUP, WAL_SETTINGS,
1651                         gettext_noop("WAL writer sleep time between WAL flushes."),
1652                         NULL,
1653                         GUC_UNIT_MS
1654                 },
1655                 &WalWriterDelay,
1656                 200, 1, 10000, NULL, NULL
1657         },
1658
1659         {
1660                 {"commit_delay", PGC_USERSET, WAL_SETTINGS,
1661                         gettext_noop("Sets the delay in microseconds between transaction commit and "
1662                                                  "flushing WAL to disk."),
1663                         NULL
1664                 },
1665                 &CommitDelay,
1666                 0, 0, 100000, NULL, NULL
1667         },
1668
1669         {
1670                 {"commit_siblings", PGC_USERSET, WAL_SETTINGS,
1671                         gettext_noop("Sets the minimum concurrent open transactions before performing "
1672                                                  "commit_delay."),
1673                         NULL
1674                 },
1675                 &CommitSiblings,
1676                 5, 1, 1000, NULL, NULL
1677         },
1678
1679         {
1680                 {"extra_float_digits", PGC_USERSET, CLIENT_CONN_LOCALE,
1681                         gettext_noop("Sets the number of digits displayed for floating-point values."),
1682                         gettext_noop("This affects real, double precision, and geometric data types. "
1683                          "The parameter value is added to the standard number of digits "
1684                                                  "(FLT_DIG or DBL_DIG as appropriate).")
1685                 },
1686                 &extra_float_digits,
1687                 0, -15, 3, NULL, NULL
1688         },
1689
1690         {
1691                 {"log_min_duration_statement", PGC_SUSET, LOGGING_WHEN,
1692                         gettext_noop("Sets the minimum execution time above which "
1693                                                  "statements will be logged."),
1694                         gettext_noop("Zero prints all queries. -1 turns this feature off."),
1695                         GUC_UNIT_MS
1696                 },
1697                 &log_min_duration_statement,
1698                 -1, -1, INT_MAX / 1000, NULL, NULL
1699         },
1700
1701         {
1702                 {"log_autovacuum_min_duration", PGC_SIGHUP, LOGGING_WHAT,
1703                         gettext_noop("Sets the minimum execution time above which "
1704                                                  "autovacuum actions will be logged."),
1705                         gettext_noop("Zero prints all actions. -1 turns autovacuum logging off."),
1706                         GUC_UNIT_MS
1707                 },
1708                 &Log_autovacuum_min_duration,
1709                 -1, -1, INT_MAX / 1000, NULL, NULL
1710         },
1711
1712         {
1713                 {"bgwriter_delay", PGC_SIGHUP, RESOURCES,
1714                         gettext_noop("Background writer sleep time between rounds."),
1715                         NULL,
1716                         GUC_UNIT_MS
1717                 },
1718                 &BgWriterDelay,
1719                 200, 10, 10000, NULL, NULL
1720         },
1721
1722         {
1723                 {"bgwriter_lru_maxpages", PGC_SIGHUP, RESOURCES,
1724                         gettext_noop("Background writer maximum number of LRU pages to flush per round."),
1725                         NULL
1726                 },
1727                 &bgwriter_lru_maxpages,
1728                 100, 0, 1000, NULL, NULL
1729         },
1730
1731         {
1732                 {"effective_io_concurrency",
1733 #ifdef USE_PREFETCH
1734                         PGC_USERSET,
1735 #else
1736                         PGC_INTERNAL,
1737 #endif
1738                         RESOURCES,
1739                         gettext_noop("Number of simultaneous requests that can be handled efficiently by the disk subsystem."),
1740                         gettext_noop("For RAID arrays, this should be approximately the number of drive spindles in the array.")
1741                 },
1742                 &effective_io_concurrency,
1743 #ifdef USE_PREFETCH
1744                 1, 0, 1000,
1745 #else
1746                 0, 0, 0,
1747 #endif
1748                 assign_effective_io_concurrency, NULL
1749         },
1750
1751         {
1752                 {"log_rotation_age", PGC_SIGHUP, LOGGING_WHERE,
1753                         gettext_noop("Automatic log file rotation will occur after N minutes."),
1754                         NULL,
1755                         GUC_UNIT_MIN
1756                 },
1757                 &Log_RotationAge,
1758                 HOURS_PER_DAY * MINS_PER_HOUR, 0, INT_MAX / MINS_PER_HOUR, NULL, NULL
1759         },
1760
1761         {
1762                 {"log_rotation_size", PGC_SIGHUP, LOGGING_WHERE,
1763                         gettext_noop("Automatic log file rotation will occur after N kilobytes."),
1764                         NULL,
1765                         GUC_UNIT_KB
1766                 },
1767                 &Log_RotationSize,
1768                 10 * 1024, 0, INT_MAX / 1024, NULL, NULL
1769         },
1770
1771         {
1772                 {"max_function_args", PGC_INTERNAL, PRESET_OPTIONS,
1773                         gettext_noop("Shows the maximum number of function arguments."),
1774                         NULL,
1775                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1776                 },
1777                 &max_function_args,
1778                 FUNC_MAX_ARGS, FUNC_MAX_ARGS, FUNC_MAX_ARGS, NULL, NULL
1779         },
1780
1781         {
1782                 {"max_index_keys", PGC_INTERNAL, PRESET_OPTIONS,
1783                         gettext_noop("Shows the maximum number of index keys."),
1784                         NULL,
1785                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1786                 },
1787                 &max_index_keys,
1788                 INDEX_MAX_KEYS, INDEX_MAX_KEYS, INDEX_MAX_KEYS, NULL, NULL
1789         },
1790
1791         {
1792                 {"max_identifier_length", PGC_INTERNAL, PRESET_OPTIONS,
1793                         gettext_noop("Shows the maximum identifier length."),
1794                         NULL,
1795                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1796                 },
1797                 &max_identifier_length,
1798                 NAMEDATALEN - 1, NAMEDATALEN - 1, NAMEDATALEN - 1, NULL, NULL
1799         },
1800
1801         {
1802                 {"block_size", PGC_INTERNAL, PRESET_OPTIONS,
1803                         gettext_noop("Shows the size of a disk block."),
1804                         NULL,
1805                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1806                 },
1807                 &block_size,
1808                 BLCKSZ, BLCKSZ, BLCKSZ, NULL, NULL
1809         },
1810
1811         {
1812                 {"segment_size", PGC_INTERNAL, PRESET_OPTIONS,
1813                         gettext_noop("Shows the number of pages per disk file."),
1814                         NULL,
1815                         GUC_UNIT_BLOCKS | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1816                 },
1817                 &segment_size,
1818                 RELSEG_SIZE, RELSEG_SIZE, RELSEG_SIZE, NULL, NULL
1819         },
1820
1821         {
1822                 {"wal_block_size", PGC_INTERNAL, PRESET_OPTIONS,
1823                         gettext_noop("Shows the block size in the write ahead log."),
1824                         NULL,
1825                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1826                 },
1827                 &wal_block_size,
1828                 XLOG_BLCKSZ, XLOG_BLCKSZ, XLOG_BLCKSZ, NULL, NULL
1829         },
1830
1831         {
1832                 {"wal_segment_size", PGC_INTERNAL, PRESET_OPTIONS,
1833                         gettext_noop("Shows the number of pages per write ahead log segment."),
1834                         NULL,
1835                         GUC_UNIT_XBLOCKS | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1836                 },
1837                 &wal_segment_size,
1838                 (XLOG_SEG_SIZE / XLOG_BLCKSZ),
1839                 (XLOG_SEG_SIZE / XLOG_BLCKSZ),
1840                 (XLOG_SEG_SIZE / XLOG_BLCKSZ),
1841                 NULL, NULL
1842         },
1843
1844         {
1845                 {"autovacuum_naptime", PGC_SIGHUP, AUTOVACUUM,
1846                         gettext_noop("Time to sleep between autovacuum runs."),
1847                         NULL,
1848                         GUC_UNIT_S
1849                 },
1850                 &autovacuum_naptime,
1851                 60, 1, INT_MAX / 1000, NULL, NULL
1852         },
1853         {
1854                 {"autovacuum_vacuum_threshold", PGC_SIGHUP, AUTOVACUUM,
1855                         gettext_noop("Minimum number of tuple updates or deletes prior to vacuum."),
1856                         NULL
1857                 },
1858                 &autovacuum_vac_thresh,
1859                 50, 0, INT_MAX, NULL, NULL
1860         },
1861         {
1862                 {"autovacuum_analyze_threshold", PGC_SIGHUP, AUTOVACUUM,
1863                         gettext_noop("Minimum number of tuple inserts, updates or deletes prior to analyze."),
1864                         NULL
1865                 },
1866                 &autovacuum_anl_thresh,
1867                 50, 0, INT_MAX, NULL, NULL
1868         },
1869         {
1870                 /* see varsup.c for why this is PGC_POSTMASTER not PGC_SIGHUP */
1871                 {"autovacuum_freeze_max_age", PGC_POSTMASTER, AUTOVACUUM,
1872                         gettext_noop("Age at which to autovacuum a table to prevent transaction ID wraparound."),
1873                         NULL
1874                 },
1875                 &autovacuum_freeze_max_age,
1876                 /* see pg_resetxlog if you change the upper-limit value */
1877                 200000000, 100000000, 2000000000, NULL, NULL
1878         },
1879         {
1880                 /* see max_connections */
1881                 {"autovacuum_max_workers", PGC_POSTMASTER, AUTOVACUUM,
1882                         gettext_noop("Sets the maximum number of simultaneously running autovacuum worker processes."),
1883                         NULL
1884                 },
1885                 &autovacuum_max_workers,
1886                 3, 1, INT_MAX / 4, assign_autovacuum_max_workers, NULL
1887         },
1888
1889         {
1890                 {"tcp_keepalives_idle", PGC_USERSET, CLIENT_CONN_OTHER,
1891                         gettext_noop("Time between issuing TCP keepalives."),
1892                         gettext_noop("A value of 0 uses the system default."),
1893                         GUC_UNIT_S
1894                 },
1895                 &tcp_keepalives_idle,
1896                 0, 0, INT_MAX, assign_tcp_keepalives_idle, show_tcp_keepalives_idle
1897         },
1898
1899         {
1900                 {"tcp_keepalives_interval", PGC_USERSET, CLIENT_CONN_OTHER,
1901                         gettext_noop("Time between TCP keepalive retransmits."),
1902                         gettext_noop("A value of 0 uses the system default."),
1903                         GUC_UNIT_S
1904                 },
1905                 &tcp_keepalives_interval,
1906                 0, 0, INT_MAX, assign_tcp_keepalives_interval, show_tcp_keepalives_interval
1907         },
1908
1909         {
1910                 {"tcp_keepalives_count", PGC_USERSET, CLIENT_CONN_OTHER,
1911                         gettext_noop("Maximum number of TCP keepalive retransmits."),
1912                         gettext_noop("This controls the number of consecutive keepalive retransmits that can be "
1913                                                  "lost before a connection is considered dead. A value of 0 uses the "
1914                                                  "system default."),
1915                 },
1916                 &tcp_keepalives_count,
1917                 0, 0, INT_MAX, assign_tcp_keepalives_count, show_tcp_keepalives_count
1918         },
1919
1920         {
1921                 {"gin_fuzzy_search_limit", PGC_USERSET, CLIENT_CONN_OTHER,
1922                         gettext_noop("Sets the maximum allowed result for exact search by GIN."),
1923                         NULL,
1924                         0
1925                 },
1926                 &GinFuzzySearchLimit,
1927                 0, 0, INT_MAX, NULL, NULL
1928         },
1929
1930         {
1931                 {"effective_cache_size", PGC_USERSET, QUERY_TUNING_COST,
1932                         gettext_noop("Sets the planner's assumption about the size of the disk cache."),
1933                         gettext_noop("That is, the portion of the kernel's disk cache that "
1934                                                  "will be used for PostgreSQL data files. This is measured in disk "
1935                                                  "pages, which are normally 8 kB each."),
1936                         GUC_UNIT_BLOCKS,
1937                 },
1938                 &effective_cache_size,
1939                 DEFAULT_EFFECTIVE_CACHE_SIZE, 1, INT_MAX, NULL, NULL
1940         },
1941
1942         {
1943                 /* Can't be set in postgresql.conf */
1944                 {"server_version_num", PGC_INTERNAL, PRESET_OPTIONS,
1945                         gettext_noop("Shows the server version as an integer."),
1946                         NULL,
1947                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1948                 },
1949                 &server_version_num,
1950                 PG_VERSION_NUM, PG_VERSION_NUM, PG_VERSION_NUM, NULL, NULL
1951         },
1952
1953         {
1954                 {"log_temp_files", PGC_SUSET, LOGGING_WHAT,
1955                         gettext_noop("Log the use of temporary files larger than this number of kilobytes."),
1956                         gettext_noop("Zero logs all files. The default is -1 (turning this feature off)."),
1957                         GUC_UNIT_KB
1958                 },
1959                 &log_temp_files,
1960                 -1, -1, INT_MAX, NULL, NULL
1961         },
1962
1963         {
1964                 {"track_activity_query_size", PGC_POSTMASTER, RESOURCES_MEM,
1965                         gettext_noop("Sets the size reserved for pg_stat_activity.current_query, in bytes."),
1966                         NULL,
1967                 },
1968                 &pgstat_track_activity_query_size,
1969                 1024, 100, 102400, NULL, NULL
1970         },
1971
1972         /* End-of-list marker */
1973         {
1974                 {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL
1975         }
1976 };
1977
1978
1979 static struct config_real ConfigureNamesReal[] =
1980 {
1981         {
1982                 {"seq_page_cost", PGC_USERSET, QUERY_TUNING_COST,
1983                         gettext_noop("Sets the planner's estimate of the cost of a "
1984                                                  "sequentially fetched disk page."),
1985                         NULL
1986                 },
1987                 &seq_page_cost,
1988                 DEFAULT_SEQ_PAGE_COST, 0, DBL_MAX, NULL, NULL
1989         },
1990         {
1991                 {"random_page_cost", PGC_USERSET, QUERY_TUNING_COST,
1992                         gettext_noop("Sets the planner's estimate of the cost of a "
1993                                                  "nonsequentially fetched disk page."),
1994                         NULL
1995                 },
1996                 &random_page_cost,
1997                 DEFAULT_RANDOM_PAGE_COST, 0, DBL_MAX, NULL, NULL
1998         },
1999         {
2000                 {"cpu_tuple_cost", PGC_USERSET, QUERY_TUNING_COST,
2001                         gettext_noop("Sets the planner's estimate of the cost of "
2002                                                  "processing each tuple (row)."),
2003                         NULL
2004                 },
2005                 &cpu_tuple_cost,
2006                 DEFAULT_CPU_TUPLE_COST, 0, DBL_MAX, NULL, NULL
2007         },
2008         {
2009                 {"cpu_index_tuple_cost", PGC_USERSET, QUERY_TUNING_COST,
2010                         gettext_noop("Sets the planner's estimate of the cost of "
2011                                                  "processing each index entry during an index scan."),
2012                         NULL
2013                 },
2014                 &cpu_index_tuple_cost,
2015                 DEFAULT_CPU_INDEX_TUPLE_COST, 0, DBL_MAX, NULL, NULL
2016         },
2017         {
2018                 {"cpu_operator_cost", PGC_USERSET, QUERY_TUNING_COST,
2019                         gettext_noop("Sets the planner's estimate of the cost of "
2020                                                  "processing each operator or function call."),
2021                         NULL
2022                 },
2023                 &cpu_operator_cost,
2024                 DEFAULT_CPU_OPERATOR_COST, 0, DBL_MAX, NULL, NULL
2025         },
2026
2027         {
2028                 {"cursor_tuple_fraction", PGC_USERSET, QUERY_TUNING_OTHER,
2029                         gettext_noop("Sets the planner's estimate of the fraction of "
2030                                                  "a cursor's rows that will be retrieved."),
2031                         NULL
2032                 },
2033                 &cursor_tuple_fraction,
2034                 DEFAULT_CURSOR_TUPLE_FRACTION, 0.0, 1.0, NULL, NULL
2035         },
2036
2037         {
2038                 {"geqo_selection_bias", PGC_USERSET, QUERY_TUNING_GEQO,
2039                         gettext_noop("GEQO: selective pressure within the population."),
2040                         NULL
2041                 },
2042                 &Geqo_selection_bias,
2043                 DEFAULT_GEQO_SELECTION_BIAS, MIN_GEQO_SELECTION_BIAS,
2044                 MAX_GEQO_SELECTION_BIAS, NULL, NULL
2045         },
2046         {
2047                 {"geqo_seed", PGC_USERSET, QUERY_TUNING_GEQO,
2048                         gettext_noop("GEQO: seed for random path selection."),
2049                         NULL
2050                 },
2051                 &Geqo_seed,
2052                 0.0, 0.0, 1.0, NULL, NULL
2053         },
2054
2055         {
2056                 {"bgwriter_lru_multiplier", PGC_SIGHUP, RESOURCES,
2057                         gettext_noop("Multiple of the average buffer usage to free per round."),
2058                         NULL
2059                 },
2060                 &bgwriter_lru_multiplier,
2061                 2.0, 0.0, 10.0, NULL, NULL
2062         },
2063
2064         {
2065                 {"seed", PGC_USERSET, UNGROUPED,
2066                         gettext_noop("Sets the seed for random-number generation."),
2067                         NULL,
2068                         GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2069                 },
2070                 &phony_random_seed,
2071                 0.0, -1.0, 1.0, assign_random_seed, show_random_seed
2072         },
2073
2074         {
2075                 {"autovacuum_vacuum_scale_factor", PGC_SIGHUP, AUTOVACUUM,
2076                         gettext_noop("Number of tuple updates or deletes prior to vacuum as a fraction of reltuples."),
2077                         NULL
2078                 },
2079                 &autovacuum_vac_scale,
2080                 0.2, 0.0, 100.0, NULL, NULL
2081         },
2082         {
2083                 {"autovacuum_analyze_scale_factor", PGC_SIGHUP, AUTOVACUUM,
2084                         gettext_noop("Number of tuple inserts, updates or deletes prior to analyze as a fraction of reltuples."),
2085                         NULL
2086                 },
2087                 &autovacuum_anl_scale,
2088                 0.1, 0.0, 100.0, NULL, NULL
2089         },
2090
2091         {
2092                 {"checkpoint_completion_target", PGC_SIGHUP, WAL_CHECKPOINTS,
2093                         gettext_noop("Time spent flushing dirty buffers during checkpoint, as fraction of checkpoint interval."),
2094                         NULL
2095                 },
2096                 &CheckPointCompletionTarget,
2097                 0.5, 0.0, 1.0, NULL, NULL
2098         },
2099
2100         /* End-of-list marker */
2101         {
2102                 {NULL, 0, 0, NULL, NULL}, NULL, 0.0, 0.0, 0.0, NULL, NULL
2103         }
2104 };
2105
2106
2107 static struct config_string ConfigureNamesString[] =
2108 {
2109         {
2110                 {"archive_command", PGC_SIGHUP, WAL_SETTINGS,
2111                         gettext_noop("Sets the shell command that will be called to archive a WAL file."),
2112                         NULL
2113                 },
2114                 &XLogArchiveCommand,
2115                 "", NULL, show_archive_command
2116         },
2117
2118         {
2119                 {"client_encoding", PGC_USERSET, CLIENT_CONN_LOCALE,
2120                         gettext_noop("Sets the client's character set encoding."),
2121                         NULL,
2122                         GUC_IS_NAME | GUC_REPORT
2123                 },
2124                 &client_encoding_string,
2125                 "SQL_ASCII", assign_client_encoding, NULL
2126         },
2127
2128         {
2129                 {"log_line_prefix", PGC_SIGHUP, LOGGING_WHAT,
2130                         gettext_noop("Controls information prefixed to each log line."),
2131                         gettext_noop("If blank, no prefix is used.")
2132                 },
2133                 &Log_line_prefix,
2134                 "", NULL, NULL
2135         },
2136
2137         {
2138                 {"log_timezone", PGC_SIGHUP, LOGGING_WHAT,
2139                         gettext_noop("Sets the time zone to use in log messages."),
2140                         NULL
2141                 },
2142                 &log_timezone_string,
2143                 "UNKNOWN", assign_log_timezone, show_log_timezone
2144         },
2145
2146         {
2147                 {"DateStyle", PGC_USERSET, CLIENT_CONN_LOCALE,
2148                         gettext_noop("Sets the display format for date and time values."),
2149                         gettext_noop("Also controls interpretation of ambiguous "
2150                                                  "date inputs."),
2151                         GUC_LIST_INPUT | GUC_REPORT
2152                 },
2153                 &datestyle_string,
2154                 "ISO, MDY", assign_datestyle, NULL
2155         },
2156
2157         {
2158                 {"default_tablespace", PGC_USERSET, CLIENT_CONN_STATEMENT,
2159                         gettext_noop("Sets the default tablespace to create tables and indexes in."),
2160                         gettext_noop("An empty string selects the database's default tablespace."),
2161                         GUC_IS_NAME
2162                 },
2163                 &default_tablespace,
2164                 "", assign_default_tablespace, NULL
2165         },
2166
2167         {
2168                 {"temp_tablespaces", PGC_USERSET, CLIENT_CONN_STATEMENT,
2169                         gettext_noop("Sets the tablespace(s) to use for temporary tables and sort files."),
2170                         NULL,
2171                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2172                 },
2173                 &temp_tablespaces,
2174                 "", assign_temp_tablespaces, NULL
2175         },
2176
2177         {
2178                 {"dynamic_library_path", PGC_SUSET, CLIENT_CONN_OTHER,
2179                         gettext_noop("Sets the path for dynamically loadable modules."),
2180                         gettext_noop("If a dynamically loadable module needs to be opened and "
2181                                                  "the specified name does not have a directory component (i.e., the "
2182                                                  "name does not contain a slash), the system will search this path for "
2183                                                  "the specified file."),
2184                         GUC_SUPERUSER_ONLY
2185                 },
2186                 &Dynamic_library_path,
2187                 "$libdir", NULL, NULL
2188         },
2189
2190         {
2191                 {"krb_server_keyfile", PGC_SIGHUP, CONN_AUTH_SECURITY,
2192                         gettext_noop("Sets the location of the Kerberos server key file."),
2193                         NULL,
2194                         GUC_SUPERUSER_ONLY
2195                 },
2196                 &pg_krb_server_keyfile,
2197                 PG_KRB_SRVTAB, NULL, NULL
2198         },
2199
2200         {
2201                 {"krb_srvname", PGC_SIGHUP, CONN_AUTH_SECURITY,
2202                         gettext_noop("Sets the name of the Kerberos service."),
2203                         NULL
2204                 },
2205                 &pg_krb_srvnam,
2206                 PG_KRB_SRVNAM, NULL, NULL
2207         },
2208
2209         {
2210                 {"bonjour_name", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2211                         gettext_noop("Sets the Bonjour service name."),
2212                         NULL
2213                 },
2214                 &bonjour_name,
2215                 "", NULL, NULL
2216         },
2217
2218         /* See main.c about why defaults for LC_foo are not all alike */
2219
2220         {
2221                 {"lc_collate", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2222                         gettext_noop("Shows the collation order locale."),
2223                         NULL,
2224                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2225                 },
2226                 &locale_collate,
2227                 "C", NULL, NULL
2228         },
2229
2230         {
2231                 {"lc_ctype", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2232                         gettext_noop("Shows the character classification and case conversion locale."),
2233                         NULL,
2234                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2235                 },
2236                 &locale_ctype,
2237                 "C", NULL, NULL
2238         },
2239
2240         {
2241                 {"lc_messages", PGC_SUSET, CLIENT_CONN_LOCALE,
2242                         gettext_noop("Sets the language in which messages are displayed."),
2243                         NULL
2244                 },
2245                 &locale_messages,
2246                 "", locale_messages_assign, NULL
2247         },
2248
2249         {
2250                 {"lc_monetary", PGC_USERSET, CLIENT_CONN_LOCALE,
2251                         gettext_noop("Sets the locale for formatting monetary amounts."),
2252                         NULL
2253                 },
2254                 &locale_monetary,
2255                 "C", locale_monetary_assign, NULL
2256         },
2257
2258         {
2259                 {"lc_numeric", PGC_USERSET, CLIENT_CONN_LOCALE,
2260                         gettext_noop("Sets the locale for formatting numbers."),
2261                         NULL
2262                 },
2263                 &locale_numeric,
2264                 "C", locale_numeric_assign, NULL
2265         },
2266
2267         {
2268                 {"lc_time", PGC_USERSET, CLIENT_CONN_LOCALE,
2269                         gettext_noop("Sets the locale for formatting date and time values."),
2270                         NULL
2271                 },
2272                 &locale_time,
2273                 "C", locale_time_assign, NULL
2274         },
2275
2276         {
2277                 {"shared_preload_libraries", PGC_POSTMASTER, RESOURCES_KERNEL,
2278                         gettext_noop("Lists shared libraries to preload into server."),
2279                         NULL,
2280                         GUC_LIST_INPUT | GUC_LIST_QUOTE | GUC_SUPERUSER_ONLY
2281                 },
2282                 &shared_preload_libraries_string,
2283                 "", NULL, NULL
2284         },
2285
2286         {
2287                 {"local_preload_libraries", PGC_BACKEND, CLIENT_CONN_OTHER,
2288                         gettext_noop("Lists shared libraries to preload into each backend."),
2289                         NULL,
2290                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2291                 },
2292                 &local_preload_libraries_string,
2293                 "", NULL, NULL
2294         },
2295
2296         {
2297                 {"search_path", PGC_USERSET, CLIENT_CONN_STATEMENT,
2298                         gettext_noop("Sets the schema search order for names that are not schema-qualified."),
2299                         NULL,
2300                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2301                 },
2302                 &namespace_search_path,
2303                 "\"$user\",public", assign_search_path, NULL
2304         },
2305
2306         {
2307                 /* Can't be set in postgresql.conf */
2308                 {"server_encoding", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2309                         gettext_noop("Sets the server (database) character set encoding."),
2310                         NULL,
2311                         GUC_IS_NAME | GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2312                 },
2313                 &server_encoding_string,
2314                 "SQL_ASCII", NULL, NULL
2315         },
2316
2317         {
2318                 /* Can't be set in postgresql.conf */
2319                 {"server_version", PGC_INTERNAL, PRESET_OPTIONS,
2320                         gettext_noop("Shows the server version."),
2321                         NULL,
2322                         GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2323                 },
2324                 &server_version_string,
2325                 PG_VERSION, NULL, NULL
2326         },
2327
2328         {
2329                 /* Not for general use --- used by SET ROLE */
2330                 {"role", PGC_USERSET, UNGROUPED,
2331                         gettext_noop("Sets the current role."),
2332                         NULL,
2333                         GUC_IS_NAME | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE | GUC_NOT_WHILE_SEC_REST
2334                 },
2335                 &role_string,
2336                 "none", assign_role, show_role
2337         },
2338
2339         {
2340                 /* Not for general use --- used by SET SESSION AUTHORIZATION */
2341                 {"session_authorization", PGC_USERSET, UNGROUPED,
2342                         gettext_noop("Sets the session user name."),
2343                         NULL,
2344                         GUC_IS_NAME | GUC_REPORT | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE | GUC_NOT_WHILE_SEC_REST
2345                 },
2346                 &session_authorization_string,
2347                 NULL, assign_session_authorization, show_session_authorization
2348         },
2349
2350         {
2351                 {"log_destination", PGC_SIGHUP, LOGGING_WHERE,
2352                         gettext_noop("Sets the destination for server log output."),
2353                         gettext_noop("Valid values are combinations of \"stderr\", "
2354                                                  "\"syslog\", \"csvlog\", and \"eventlog\", "
2355                                                  "depending on the platform."),
2356                         GUC_LIST_INPUT
2357                 },
2358                 &log_destination_string,
2359                 "stderr", assign_log_destination, NULL
2360         },
2361         {
2362                 {"log_directory", PGC_SIGHUP, LOGGING_WHERE,
2363                         gettext_noop("Sets the destination directory for log files."),
2364                         gettext_noop("Can be specified as relative to the data directory "
2365                                                  "or as absolute path."),
2366                         GUC_SUPERUSER_ONLY
2367                 },
2368                 &Log_directory,
2369                 "pg_log", assign_canonical_path, NULL
2370         },
2371         {
2372                 {"log_filename", PGC_SIGHUP, LOGGING_WHERE,
2373                         gettext_noop("Sets the file name pattern for log files."),
2374                         NULL,
2375                         GUC_SUPERUSER_ONLY
2376                 },
2377                 &Log_filename,
2378                 "postgresql-%Y-%m-%d_%H%M%S.log", NULL, NULL
2379         },
2380
2381 #ifdef HAVE_SYSLOG
2382         {
2383                 {"syslog_ident", PGC_SIGHUP, LOGGING_WHERE,
2384                         gettext_noop("Sets the program name used to identify PostgreSQL "
2385                                                  "messages in syslog."),
2386                         NULL
2387                 },
2388                 &syslog_ident_str,
2389                 "postgres", assign_syslog_ident, NULL
2390         },
2391 #endif
2392
2393         {
2394                 {"TimeZone", PGC_USERSET, CLIENT_CONN_LOCALE,
2395                         gettext_noop("Sets the time zone for displaying and interpreting time stamps."),
2396                         NULL,
2397                         GUC_REPORT
2398                 },
2399                 &timezone_string,
2400                 "UNKNOWN", assign_timezone, show_timezone
2401         },
2402         {
2403                 {"timezone_abbreviations", PGC_USERSET, CLIENT_CONN_LOCALE,
2404                         gettext_noop("Selects a file of time zone abbreviations."),
2405                         NULL
2406                 },
2407                 &timezone_abbreviations_string,
2408                 "UNKNOWN", assign_timezone_abbreviations, NULL
2409         },
2410
2411         {
2412                 {"transaction_isolation", PGC_USERSET, CLIENT_CONN_STATEMENT,
2413                         gettext_noop("Sets the current transaction's isolation level."),
2414                         NULL,
2415                         GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2416                 },
2417                 &XactIsoLevel_string,
2418                 NULL, assign_XactIsoLevel, show_XactIsoLevel
2419         },
2420
2421         {
2422                 {"unix_socket_group", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2423                         gettext_noop("Sets the owning group of the Unix-domain socket."),
2424                         gettext_noop("The owning user of the socket is always the user "
2425                                                  "that starts the server.")
2426                 },
2427                 &Unix_socket_group,
2428                 "", NULL, NULL
2429         },
2430
2431         {
2432                 {"unix_socket_directory", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2433                         gettext_noop("Sets the directory where the Unix-domain socket will be created."),
2434                         NULL,
2435                         GUC_SUPERUSER_ONLY
2436                 },
2437                 &UnixSocketDir,
2438                 "", assign_canonical_path, NULL
2439         },
2440
2441         {
2442                 {"listen_addresses", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2443                         gettext_noop("Sets the host name or IP address(es) to listen to."),
2444                         NULL,
2445                         GUC_LIST_INPUT
2446                 },
2447                 &ListenAddresses,
2448                 "localhost", NULL, NULL
2449         },
2450
2451         {
2452                 {"custom_variable_classes", PGC_SIGHUP, CUSTOM_OPTIONS,
2453                         gettext_noop("Sets the list of known custom variable classes."),
2454                         NULL,
2455                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2456                 },
2457                 &custom_variable_classes,
2458                 NULL, assign_custom_variable_classes, NULL
2459         },
2460
2461         {
2462                 {"data_directory", PGC_POSTMASTER, FILE_LOCATIONS,
2463                         gettext_noop("Sets the server's data directory."),
2464                         NULL,
2465                         GUC_SUPERUSER_ONLY
2466                 },
2467                 &data_directory,
2468                 NULL, NULL, NULL
2469         },
2470
2471         {
2472                 {"config_file", PGC_POSTMASTER, FILE_LOCATIONS,
2473                         gettext_noop("Sets the server's main configuration file."),
2474                         NULL,
2475                         GUC_DISALLOW_IN_FILE | GUC_SUPERUSER_ONLY
2476                 },
2477                 &ConfigFileName,
2478                 NULL, NULL, NULL
2479         },
2480
2481         {
2482                 {"hba_file", PGC_POSTMASTER, FILE_LOCATIONS,
2483                         gettext_noop("Sets the server's \"hba\" configuration file."),
2484                         NULL,
2485                         GUC_SUPERUSER_ONLY
2486                 },
2487                 &HbaFileName,
2488                 NULL, NULL, NULL
2489         },
2490
2491         {
2492                 {"ident_file", PGC_POSTMASTER, FILE_LOCATIONS,
2493                         gettext_noop("Sets the server's \"ident\" configuration file."),
2494                         NULL,
2495                         GUC_SUPERUSER_ONLY
2496                 },
2497                 &IdentFileName,
2498                 NULL, NULL, NULL
2499         },
2500
2501         {
2502                 {"external_pid_file", PGC_POSTMASTER, FILE_LOCATIONS,
2503                         gettext_noop("Writes the postmaster PID to the specified file."),
2504                         NULL,
2505                         GUC_SUPERUSER_ONLY
2506                 },
2507                 &external_pid_file,
2508                 NULL, assign_canonical_path, NULL
2509         },
2510
2511         {
2512                 {"stats_temp_directory", PGC_SIGHUP, STATS_COLLECTOR,
2513                         gettext_noop("Writes temporary statistics files to the specified directory."),
2514                         NULL,
2515                         GUC_SUPERUSER_ONLY
2516                 },
2517                 &pgstat_temp_directory,
2518                 "pg_stat_tmp", assign_pgstat_temp_directory, NULL
2519         },
2520
2521         {
2522                 {"default_text_search_config", PGC_USERSET, CLIENT_CONN_LOCALE,
2523                         gettext_noop("Sets default text search configuration."),
2524                         NULL
2525                 },
2526                 &TSCurrentConfig,
2527                 "pg_catalog.simple", assignTSCurrentConfig, NULL
2528         },
2529
2530 #ifdef USE_SSL
2531         {
2532                 {"ssl_ciphers", PGC_POSTMASTER, CONN_AUTH_SECURITY,
2533                         gettext_noop("Sets the list of allowed SSL ciphers."),
2534                         NULL,
2535                         GUC_SUPERUSER_ONLY
2536                 },
2537                 &SSLCipherSuites,
2538                 "ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH", NULL, NULL
2539         },
2540 #endif   /* USE_SSL */
2541
2542         {
2543                 {"default_do_language", PGC_USERSET, CLIENT_CONN_STATEMENT,
2544                         gettext_noop("Sets the language used in DO statement if LANGUAGE is not specified."),
2545                         NULL
2546                 },
2547                 &default_do_language,
2548                 "plpgsql", NULL, NULL
2549         },
2550
2551         {
2552                 {"application_name", PGC_USERSET, LOGGING,
2553                  gettext_noop("Sets the application name to be reported in statistics and logs."),
2554                  NULL,
2555                  GUC_IS_NAME | GUC_REPORT | GUC_NOT_IN_SAMPLE
2556                 },
2557                 &application_name,
2558                 "", assign_application_name, NULL
2559         },
2560
2561         /* End-of-list marker */
2562         {
2563                 {NULL, 0, 0, NULL, NULL}, NULL, NULL, NULL, NULL
2564         }
2565 };
2566
2567
2568 static struct config_enum ConfigureNamesEnum[] =
2569 {
2570         {
2571                 {"backslash_quote", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
2572                         gettext_noop("Sets whether \"\\'\" is allowed in string literals."),
2573                         NULL
2574                 },
2575                 &backslash_quote,
2576                 BACKSLASH_QUOTE_SAFE_ENCODING, backslash_quote_options, NULL, NULL
2577         },
2578
2579         {
2580                 {"bytea_output", PGC_USERSET, CLIENT_CONN_STATEMENT,
2581                         gettext_noop("Sets the output format for bytea."),
2582                         NULL
2583                 },
2584                 &bytea_output,
2585                 BYTEA_OUTPUT_HEX, bytea_output_options, NULL, NULL
2586         },
2587
2588         {
2589                 {"client_min_messages", PGC_USERSET, LOGGING_WHEN,
2590                         gettext_noop("Sets the message levels that are sent to the client."),
2591                         gettext_noop("Each level includes all the levels that follow it. The later"
2592                                                  " the level, the fewer messages are sent.")
2593                 },
2594                 &client_min_messages,
2595                 NOTICE, client_message_level_options, NULL, NULL
2596         },
2597
2598         {
2599                 {"constraint_exclusion", PGC_USERSET, QUERY_TUNING_OTHER,
2600                         gettext_noop("Enables the planner to use constraints to optimize queries."),
2601                         gettext_noop("Table scans will be skipped if their constraints"
2602                                                  " guarantee that no rows match the query.")
2603                 },
2604                 &constraint_exclusion,
2605                 CONSTRAINT_EXCLUSION_PARTITION, constraint_exclusion_options,
2606                 NULL, NULL
2607         },
2608
2609         {
2610                 {"default_transaction_isolation", PGC_USERSET, CLIENT_CONN_STATEMENT,
2611                         gettext_noop("Sets the transaction isolation level of each new transaction."),
2612                         NULL
2613                 },
2614                 &DefaultXactIsoLevel,
2615                 XACT_READ_COMMITTED, isolation_level_options, NULL, NULL
2616         },
2617
2618         {
2619                 {"IntervalStyle", PGC_USERSET, CLIENT_CONN_LOCALE,
2620                         gettext_noop("Sets the display format for interval values."),
2621                         NULL,
2622                         GUC_REPORT
2623                 },
2624                 &IntervalStyle,
2625                 INTSTYLE_POSTGRES, intervalstyle_options, NULL, NULL
2626         },
2627
2628         {
2629                 {"log_error_verbosity", PGC_SUSET, LOGGING_WHEN,
2630                         gettext_noop("Sets the verbosity of logged messages."),
2631                         NULL
2632                 },
2633                 &Log_error_verbosity,
2634                 PGERROR_DEFAULT, log_error_verbosity_options, NULL, NULL
2635         },
2636
2637         {
2638                 {"log_min_messages", PGC_SUSET, LOGGING_WHEN,
2639                         gettext_noop("Sets the message levels that are logged."),
2640                         gettext_noop("Each level includes all the levels that follow it. The later"
2641                                                  " the level, the fewer messages are sent.")
2642                 },
2643                 &log_min_messages,
2644                 WARNING, server_message_level_options, NULL, NULL
2645         },
2646
2647         {
2648                 {"log_min_error_statement", PGC_SUSET, LOGGING_WHEN,
2649                         gettext_noop("Causes all statements generating error at or above this level to be logged."),
2650                         gettext_noop("Each level includes all the levels that follow it. The later"
2651                                                  " the level, the fewer messages are sent.")
2652                 },
2653                 &log_min_error_statement,
2654                 ERROR, server_message_level_options, NULL, NULL
2655         },
2656
2657         {
2658                 {"log_statement", PGC_SUSET, LOGGING_WHAT,
2659                         gettext_noop("Sets the type of statements logged."),
2660                         NULL
2661                 },
2662                 &log_statement,
2663                 LOGSTMT_NONE, log_statement_options, NULL, NULL
2664         },
2665
2666 #ifdef HAVE_SYSLOG
2667         {
2668                 {"syslog_facility", PGC_SIGHUP, LOGGING_WHERE,
2669                         gettext_noop("Sets the syslog \"facility\" to be used when syslog enabled."),
2670                         NULL
2671                 },
2672                 &syslog_facility,
2673                 LOG_LOCAL0, syslog_facility_options, assign_syslog_facility, NULL
2674         },
2675 #endif
2676
2677         {
2678                 {"session_replication_role", PGC_SUSET, CLIENT_CONN_STATEMENT,
2679                         gettext_noop("Sets the session's behavior for triggers and rewrite rules."),
2680                         NULL
2681                 },
2682                 &SessionReplicationRole,
2683                 SESSION_REPLICATION_ROLE_ORIGIN, session_replication_role_options,
2684                 assign_session_replication_role, NULL
2685         },
2686
2687         {
2688                 {"track_functions", PGC_SUSET, STATS_COLLECTOR,
2689                         gettext_noop("Collects function-level statistics on database activity."),
2690                         NULL
2691                 },
2692                 &pgstat_track_functions,
2693                 TRACK_FUNC_OFF, track_function_options, NULL, NULL
2694         },
2695
2696         {
2697                 {"wal_sync_method", PGC_SIGHUP, WAL_SETTINGS,
2698                         gettext_noop("Selects the method used for forcing WAL updates to disk."),
2699                         NULL
2700                 },
2701                 &sync_method,
2702                 DEFAULT_SYNC_METHOD, sync_method_options,
2703                 assign_xlog_sync_method, NULL
2704         },
2705
2706         {
2707                 {"xmlbinary", PGC_USERSET, CLIENT_CONN_STATEMENT,
2708                         gettext_noop("Sets how binary values are to be encoded in XML."),
2709                         NULL
2710                 },
2711                 &xmlbinary,
2712                 XMLBINARY_BASE64, xmlbinary_options, NULL, NULL
2713         },
2714
2715         {
2716                 {"xmloption", PGC_USERSET, CLIENT_CONN_STATEMENT,
2717                         gettext_noop("Sets whether XML data in implicit parsing and serialization "
2718                                                  "operations is to be considered as documents or content fragments."),
2719                         NULL
2720                 },
2721                 &xmloption,
2722                 XMLOPTION_CONTENT, xmloption_options, NULL, NULL
2723         },
2724
2725
2726         /* End-of-list marker */
2727         {
2728                 {NULL, 0, 0, NULL, NULL}, NULL, 0, NULL, NULL, NULL
2729         }
2730 };
2731
2732 /******** end of options list ********/
2733
2734
2735 /*
2736  * To allow continued support of obsolete names for GUC variables, we apply
2737  * the following mappings to any unrecognized name.  Note that an old name
2738  * should be mapped to a new one only if the new variable has very similar
2739  * semantics to the old.
2740  */
2741 static const char *const map_old_guc_names[] = {
2742         "sort_mem", "work_mem",
2743         "vacuum_mem", "maintenance_work_mem",
2744         NULL
2745 };
2746
2747
2748 /*
2749  * Actual lookup of variables is done through this single, sorted array.
2750  */
2751 static struct config_generic **guc_variables;
2752
2753 /* Current number of variables contained in the vector */
2754 static int      num_guc_variables;
2755
2756 /* Vector capacity */
2757 static int      size_guc_variables;
2758
2759
2760 static bool guc_dirty;                  /* TRUE if need to do commit/abort work */
2761
2762 static bool reporting_enabled;  /* TRUE to enable GUC_REPORT */
2763
2764 static int      GUCNestLevel = 0;       /* 1 when in main transaction */
2765
2766
2767 static int      guc_var_compare(const void *a, const void *b);
2768 static int      guc_name_compare(const char *namea, const char *nameb);
2769 static void InitializeOneGUCOption(struct config_generic * gconf);
2770 static void push_old_value(struct config_generic * gconf, GucAction action);
2771 static void ReportGUCOption(struct config_generic * record);
2772 static void ShowGUCConfigOption(const char *name, DestReceiver *dest);
2773 static void ShowAllGUCConfig(DestReceiver *dest);
2774 static char *_ShowOption(struct config_generic * record, bool use_units);
2775 static bool is_newvalue_equal(struct config_generic * record, const char *newvalue);
2776
2777
2778 /*
2779  * Some infrastructure for checking malloc/strdup/realloc calls
2780  */
2781 static void *
2782 guc_malloc(int elevel, size_t size)
2783 {
2784         void       *data;
2785
2786         data = malloc(size);
2787         if (data == NULL)
2788                 ereport(elevel,
2789                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2790                                  errmsg("out of memory")));
2791         return data;
2792 }
2793
2794 static void *
2795 guc_realloc(int elevel, void *old, size_t size)
2796 {
2797         void       *data;
2798
2799         data = realloc(old, size);
2800         if (data == NULL)
2801                 ereport(elevel,
2802                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2803                                  errmsg("out of memory")));
2804         return data;
2805 }
2806
2807 static char *
2808 guc_strdup(int elevel, const char *src)
2809 {
2810         char       *data;
2811
2812         data = strdup(src);
2813         if (data == NULL)
2814                 ereport(elevel,
2815                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2816                                  errmsg("out of memory")));
2817         return data;
2818 }
2819
2820
2821 /*
2822  * Support for assigning to a field of a string GUC item.  Free the prior
2823  * value if it's not referenced anywhere else in the item (including stacked
2824  * states).
2825  */
2826 static void
2827 set_string_field(struct config_string * conf, char **field, char *newval)
2828 {
2829         char       *oldval = *field;
2830         GucStack   *stack;
2831
2832         /* Do the assignment */
2833         *field = newval;
2834
2835         /* Exit if any duplicate references, or if old value was NULL anyway */
2836         if (oldval == NULL ||
2837                 oldval == *(conf->variable) ||
2838                 oldval == conf->reset_val ||
2839                 oldval == conf->boot_val)
2840                 return;
2841         for (stack = conf->gen.stack; stack; stack = stack->prev)
2842         {
2843                 if (oldval == stack->prior.stringval ||
2844                         oldval == stack->masked.stringval)
2845                         return;
2846         }
2847
2848         /* Not used anymore, so free it */
2849         free(oldval);
2850 }
2851
2852 /*
2853  * Detect whether strval is referenced anywhere in a GUC string item
2854  */
2855 static bool
2856 string_field_used(struct config_string * conf, char *strval)
2857 {
2858         GucStack   *stack;
2859
2860         if (strval == *(conf->variable) ||
2861                 strval == conf->reset_val ||
2862                 strval == conf->boot_val)
2863                 return true;
2864         for (stack = conf->gen.stack; stack; stack = stack->prev)
2865         {
2866                 if (strval == stack->prior.stringval ||
2867                         strval == stack->masked.stringval)
2868                         return true;
2869         }
2870         return false;
2871 }
2872
2873 /*
2874  * Support for copying a variable's active value into a stack entry
2875  */
2876 static void
2877 set_stack_value(struct config_generic * gconf, union config_var_value * val)
2878 {
2879         switch (gconf->vartype)
2880         {
2881                 case PGC_BOOL:
2882                         val->boolval =
2883                                 *((struct config_bool *) gconf)->variable;
2884                         break;
2885                 case PGC_INT:
2886                         val->intval =
2887                                 *((struct config_int *) gconf)->variable;
2888                         break;
2889                 case PGC_REAL:
2890                         val->realval =
2891                                 *((struct config_real *) gconf)->variable;
2892                         break;
2893                 case PGC_STRING:
2894                         /* we assume stringval is NULL if not valid */
2895                         set_string_field((struct config_string *) gconf,
2896                                                          &(val->stringval),
2897                                                          *((struct config_string *) gconf)->variable);
2898                         break;
2899                 case PGC_ENUM:
2900                         val->enumval =
2901                                 *((struct config_enum *) gconf)->variable;
2902                         break;
2903         }
2904 }
2905
2906 /*
2907  * Support for discarding a no-longer-needed value in a stack entry
2908  */
2909 static void
2910 discard_stack_value(struct config_generic * gconf, union config_var_value * val)
2911 {
2912         switch (gconf->vartype)
2913         {
2914                 case PGC_BOOL:
2915                 case PGC_INT:
2916                 case PGC_REAL:
2917                 case PGC_ENUM:
2918                         /* no need to do anything */
2919                         break;
2920                 case PGC_STRING:
2921                         set_string_field((struct config_string *) gconf,
2922                                                          &(val->stringval),
2923                                                          NULL);
2924                         break;
2925         }
2926 }
2927
2928
2929 /*
2930  * Fetch the sorted array pointer (exported for help_config.c's use ONLY)
2931  */
2932 struct config_generic **
2933 get_guc_variables(void)
2934 {
2935         return guc_variables;
2936 }
2937
2938
2939 /*
2940  * Build the sorted array.      This is split out so that it could be
2941  * re-executed after startup (eg, we could allow loadable modules to
2942  * add vars, and then we'd need to re-sort).
2943  */
2944 void
2945 build_guc_variables(void)
2946 {
2947         int                     size_vars;
2948         int                     num_vars = 0;
2949         struct config_generic **guc_vars;
2950         int                     i;
2951
2952         for (i = 0; ConfigureNamesBool[i].gen.name; i++)
2953         {
2954                 struct config_bool *conf = &ConfigureNamesBool[i];
2955
2956                 /* Rather than requiring vartype to be filled in by hand, do this: */
2957                 conf->gen.vartype = PGC_BOOL;
2958                 num_vars++;
2959         }
2960
2961         for (i = 0; ConfigureNamesInt[i].gen.name; i++)
2962         {
2963                 struct config_int *conf = &ConfigureNamesInt[i];
2964
2965                 conf->gen.vartype = PGC_INT;
2966                 num_vars++;
2967         }
2968
2969         for (i = 0; ConfigureNamesReal[i].gen.name; i++)
2970         {
2971                 struct config_real *conf = &ConfigureNamesReal[i];
2972
2973                 conf->gen.vartype = PGC_REAL;
2974                 num_vars++;
2975         }
2976
2977         for (i = 0; ConfigureNamesString[i].gen.name; i++)
2978         {
2979                 struct config_string *conf = &ConfigureNamesString[i];
2980
2981                 conf->gen.vartype = PGC_STRING;
2982                 num_vars++;
2983         }
2984
2985         for (i = 0; ConfigureNamesEnum[i].gen.name; i++)
2986         {
2987                 struct config_enum *conf = &ConfigureNamesEnum[i];
2988
2989                 conf->gen.vartype = PGC_ENUM;
2990                 num_vars++;
2991         }
2992
2993         /*
2994          * Create table with 20% slack
2995          */
2996         size_vars = num_vars + num_vars / 4;
2997
2998         guc_vars = (struct config_generic **)
2999                 guc_malloc(FATAL, size_vars * sizeof(struct config_generic *));
3000
3001         num_vars = 0;
3002
3003         for (i = 0; ConfigureNamesBool[i].gen.name; i++)
3004                 guc_vars[num_vars++] = &ConfigureNamesBool[i].gen;
3005
3006         for (i = 0; ConfigureNamesInt[i].gen.name; i++)
3007                 guc_vars[num_vars++] = &ConfigureNamesInt[i].gen;
3008
3009         for (i = 0; ConfigureNamesReal[i].gen.name; i++)
3010                 guc_vars[num_vars++] = &ConfigureNamesReal[i].gen;
3011
3012         for (i = 0; ConfigureNamesString[i].gen.name; i++)
3013                 guc_vars[num_vars++] = &ConfigureNamesString[i].gen;
3014
3015         for (i = 0; ConfigureNamesEnum[i].gen.name; i++)
3016                 guc_vars[num_vars++] = &ConfigureNamesEnum[i].gen;
3017
3018         if (guc_variables)
3019                 free(guc_variables);
3020         guc_variables = guc_vars;
3021         num_guc_variables = num_vars;
3022         size_guc_variables = size_vars;
3023         qsort((void *) guc_variables, num_guc_variables,
3024                   sizeof(struct config_generic *), guc_var_compare);
3025 }
3026
3027 /*
3028  * Add a new GUC variable to the list of known variables. The
3029  * list is expanded if needed.
3030  */
3031 static bool
3032 add_guc_variable(struct config_generic * var, int elevel)
3033 {
3034         if (num_guc_variables + 1 >= size_guc_variables)
3035         {
3036                 /*
3037                  * Increase the vector by 25%
3038                  */
3039                 int                     size_vars = size_guc_variables + size_guc_variables / 4;
3040                 struct config_generic **guc_vars;
3041
3042                 if (size_vars == 0)
3043                 {
3044                         size_vars = 100;
3045                         guc_vars = (struct config_generic **)
3046                                 guc_malloc(elevel, size_vars * sizeof(struct config_generic *));
3047                 }
3048                 else
3049                 {
3050                         guc_vars = (struct config_generic **)
3051                                 guc_realloc(elevel, guc_variables, size_vars * sizeof(struct config_generic *));
3052                 }
3053
3054                 if (guc_vars == NULL)
3055                         return false;           /* out of memory */
3056
3057                 guc_variables = guc_vars;
3058                 size_guc_variables = size_vars;
3059         }
3060         guc_variables[num_guc_variables++] = var;
3061         qsort((void *) guc_variables, num_guc_variables,
3062                   sizeof(struct config_generic *), guc_var_compare);
3063         return true;
3064 }
3065
3066 /*
3067  * Create and add a placeholder variable. It's presumed to belong
3068  * to a valid custom variable class at this point.
3069  */
3070 static struct config_generic *
3071 add_placeholder_variable(const char *name, int elevel)
3072 {
3073         size_t          sz = sizeof(struct config_string) + sizeof(char *);
3074         struct config_string *var;
3075         struct config_generic *gen;
3076
3077         var = (struct config_string *) guc_malloc(elevel, sz);
3078         if (var == NULL)
3079                 return NULL;
3080         memset(var, 0, sz);
3081         gen = &var->gen;
3082
3083         gen->name = guc_strdup(elevel, name);
3084         if (gen->name == NULL)
3085         {
3086                 free(var);
3087                 return NULL;
3088         }
3089
3090         gen->context = PGC_USERSET;
3091         gen->group = CUSTOM_OPTIONS;
3092         gen->short_desc = "GUC placeholder variable";
3093         gen->flags = GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE | GUC_CUSTOM_PLACEHOLDER;
3094         gen->vartype = PGC_STRING;
3095
3096         /*
3097          * The char* is allocated at the end of the struct since we have no
3098          * 'static' place to point to.  Note that the current value, as well as
3099          * the boot and reset values, start out NULL.
3100          */
3101         var->variable = (char **) (var + 1);
3102
3103         if (!add_guc_variable((struct config_generic *) var, elevel))
3104         {
3105                 free((void *) gen->name);
3106                 free(var);
3107                 return NULL;
3108         }
3109
3110         return gen;
3111 }
3112
3113 /*
3114  * Detect whether the portion of "name" before dotPos matches any custom
3115  * variable class name listed in custom_var_classes.  The latter must be
3116  * formatted the way that assign_custom_variable_classes does it, ie,
3117  * no whitespace.  NULL is valid for custom_var_classes.
3118  */
3119 static bool
3120 is_custom_class(const char *name, int dotPos, const char *custom_var_classes)
3121 {
3122         bool            result = false;
3123         const char *ccs = custom_var_classes;
3124
3125         if (ccs != NULL)
3126         {
3127                 const char *start = ccs;
3128
3129                 for (;; ++ccs)
3130                 {
3131                         char            c = *ccs;
3132
3133                         if (c == '\0' || c == ',')
3134                         {
3135                                 if (dotPos == ccs - start && strncmp(start, name, dotPos) == 0)
3136                                 {
3137                                         result = true;
3138                                         break;
3139                                 }
3140                                 if (c == '\0')
3141                                         break;
3142                                 start = ccs + 1;
3143                         }
3144                 }
3145         }
3146         return result;
3147 }
3148
3149 /*
3150  * Look up option NAME.  If it exists, return a pointer to its record,
3151  * else return NULL.  If create_placeholders is TRUE, we'll create a
3152  * placeholder record for a valid-looking custom variable name.
3153  */
3154 static struct config_generic *
3155 find_option(const char *name, bool create_placeholders, int elevel)
3156 {
3157         const char **key = &name;
3158         struct config_generic **res;
3159         int                     i;
3160
3161         Assert(name);
3162
3163         /*
3164          * By equating const char ** with struct config_generic *, we are assuming
3165          * the name field is first in config_generic.
3166          */
3167         res = (struct config_generic **) bsearch((void *) &key,
3168                                                                                          (void *) guc_variables,
3169                                                                                          num_guc_variables,
3170                                                                                          sizeof(struct config_generic *),
3171                                                                                          guc_var_compare);
3172         if (res)
3173                 return *res;
3174
3175         /*
3176          * See if the name is an obsolete name for a variable.  We assume that the
3177          * set of supported old names is short enough that a brute-force search is
3178          * the best way.
3179          */
3180         for (i = 0; map_old_guc_names[i] != NULL; i += 2)
3181         {
3182                 if (guc_name_compare(name, map_old_guc_names[i]) == 0)
3183                         return find_option(map_old_guc_names[i + 1], false, elevel);
3184         }
3185
3186         if (create_placeholders)
3187         {
3188                 /*
3189                  * Check if the name is qualified, and if so, check if the qualifier
3190                  * matches any custom variable class.  If so, add a placeholder.
3191                  */
3192                 const char *dot = strchr(name, GUC_QUALIFIER_SEPARATOR);
3193
3194                 if (dot != NULL &&
3195                         is_custom_class(name, dot - name, custom_variable_classes))
3196                         return add_placeholder_variable(name, elevel);
3197         }
3198
3199         /* Unknown name */
3200         return NULL;
3201 }
3202
3203
3204 /*
3205  * comparator for qsorting and bsearching guc_variables array
3206  */
3207 static int
3208 guc_var_compare(const void *a, const void *b)
3209 {
3210         struct config_generic *confa = *(struct config_generic **) a;
3211         struct config_generic *confb = *(struct config_generic **) b;
3212
3213         return guc_name_compare(confa->name, confb->name);
3214 }
3215
3216 /*
3217  * the bare comparison function for GUC names
3218  */
3219 static int
3220 guc_name_compare(const char *namea, const char *nameb)
3221 {
3222         /*
3223          * The temptation to use strcasecmp() here must be resisted, because the
3224          * array ordering has to remain stable across setlocale() calls. So, build
3225          * our own with a simple ASCII-only downcasing.
3226          */
3227         while (*namea && *nameb)
3228         {
3229                 char            cha = *namea++;
3230                 char            chb = *nameb++;
3231
3232                 if (cha >= 'A' && cha <= 'Z')
3233                         cha += 'a' - 'A';
3234                 if (chb >= 'A' && chb <= 'Z')
3235                         chb += 'a' - 'A';
3236                 if (cha != chb)
3237                         return cha - chb;
3238         }
3239         if (*namea)
3240                 return 1;                               /* a is longer */
3241         if (*nameb)
3242                 return -1;                              /* b is longer */
3243         return 0;
3244 }
3245
3246
3247 /*
3248  * Initialize GUC options during program startup.
3249  *
3250  * Note that we cannot read the config file yet, since we have not yet
3251  * processed command-line switches.
3252  */
3253 void
3254 InitializeGUCOptions(void)
3255 {
3256         int                     i;
3257         char       *env;
3258         long            stack_rlimit;
3259
3260         /*
3261          * Before log_line_prefix could possibly receive a nonempty setting, make
3262          * sure that timezone processing is minimally alive (see elog.c).
3263          */
3264         pg_timezone_pre_initialize();
3265
3266         /*
3267          * Build sorted array of all GUC variables.
3268          */
3269         build_guc_variables();
3270
3271         /*
3272          * Load all variables with their compiled-in defaults, and initialize
3273          * status fields as needed.
3274          */
3275         for (i = 0; i < num_guc_variables; i++)
3276         {
3277                 InitializeOneGUCOption(guc_variables[i]);
3278         }
3279
3280         guc_dirty = false;
3281
3282         reporting_enabled = false;
3283
3284         /*
3285          * Prevent any attempt to override the transaction modes from
3286          * non-interactive sources.
3287          */
3288         SetConfigOption("transaction_isolation", "default",
3289                                         PGC_POSTMASTER, PGC_S_OVERRIDE);
3290         SetConfigOption("transaction_read_only", "no",
3291                                         PGC_POSTMASTER, PGC_S_OVERRIDE);
3292
3293         /*
3294          * For historical reasons, some GUC parameters can receive defaults from
3295          * environment variables.  Process those settings.      NB: if you add or
3296          * remove anything here, see also ProcessConfigFile().
3297          */
3298
3299         env = getenv("PGPORT");
3300         if (env != NULL)
3301                 SetConfigOption("port", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3302
3303         env = getenv("PGDATESTYLE");
3304         if (env != NULL)
3305                 SetConfigOption("datestyle", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3306
3307         env = getenv("PGCLIENTENCODING");
3308         if (env != NULL)
3309                 SetConfigOption("client_encoding", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3310
3311         /*
3312          * rlimit isn't exactly an "environment variable", but it behaves about
3313          * the same.  If we can identify the platform stack depth rlimit, increase
3314          * default stack depth setting up to whatever is safe (but at most 2MB).
3315          */
3316         stack_rlimit = get_stack_depth_rlimit();
3317         if (stack_rlimit > 0)
3318         {
3319                 int                     new_limit = (stack_rlimit - STACK_DEPTH_SLOP) / 1024L;
3320
3321                 if (new_limit > 100)
3322                 {
3323                         char            limbuf[16];
3324
3325                         new_limit = Min(new_limit, 2048);
3326                         sprintf(limbuf, "%d", new_limit);
3327                         SetConfigOption("max_stack_depth", limbuf,
3328                                                         PGC_POSTMASTER, PGC_S_ENV_VAR);
3329                 }
3330         }
3331 }
3332
3333 /*
3334  * Initialize one GUC option variable to its compiled-in default.
3335  */
3336 static void
3337 InitializeOneGUCOption(struct config_generic * gconf)
3338 {
3339         gconf->status = 0;
3340         gconf->reset_source = PGC_S_DEFAULT;
3341         gconf->source = PGC_S_DEFAULT;
3342         gconf->stack = NULL;
3343         gconf->sourcefile = NULL;
3344         gconf->sourceline = 0;
3345
3346         switch (gconf->vartype)
3347         {
3348                 case PGC_BOOL:
3349                         {
3350                                 struct config_bool *conf = (struct config_bool *) gconf;
3351
3352                                 if (conf->assign_hook)
3353                                         if (!(*conf->assign_hook) (conf->boot_val, true,
3354                                                                                            PGC_S_DEFAULT))
3355                                                 elog(FATAL, "failed to initialize %s to %d",
3356                                                          conf->gen.name, (int) conf->boot_val);
3357                                 *conf->variable = conf->reset_val = conf->boot_val;
3358                                 break;
3359                         }
3360                 case PGC_INT:
3361                         {
3362                                 struct config_int *conf = (struct config_int *) gconf;
3363
3364                                 Assert(conf->boot_val >= conf->min);
3365                                 Assert(conf->boot_val <= conf->max);
3366                                 if (conf->assign_hook)
3367                                         if (!(*conf->assign_hook) (conf->boot_val, true,
3368                                                                                            PGC_S_DEFAULT))
3369                                                 elog(FATAL, "failed to initialize %s to %d",
3370                                                          conf->gen.name, conf->boot_val);
3371                                 *conf->variable = conf->reset_val = conf->boot_val;
3372                                 break;
3373                         }
3374                 case PGC_REAL:
3375                         {
3376                                 struct config_real *conf = (struct config_real *) gconf;
3377
3378                                 Assert(conf->boot_val >= conf->min);
3379                                 Assert(conf->boot_val <= conf->max);
3380                                 if (conf->assign_hook)
3381                                         if (!(*conf->assign_hook) (conf->boot_val, true,
3382                                                                                            PGC_S_DEFAULT))
3383                                                 elog(FATAL, "failed to initialize %s to %g",
3384                                                          conf->gen.name, conf->boot_val);
3385                                 *conf->variable = conf->reset_val = conf->boot_val;
3386                                 break;
3387                         }
3388                 case PGC_STRING:
3389                         {
3390                                 struct config_string *conf = (struct config_string *) gconf;
3391                                 char       *str;
3392
3393                                 *conf->variable = NULL;
3394                                 conf->reset_val = NULL;
3395
3396                                 if (conf->boot_val == NULL)
3397                                 {
3398                                         /* leave the value NULL, do not call assign hook */
3399                                         break;
3400                                 }
3401
3402                                 str = guc_strdup(FATAL, conf->boot_val);
3403                                 conf->reset_val = str;
3404
3405                                 if (conf->assign_hook)
3406                                 {
3407                                         const char *newstr;
3408
3409                                         newstr = (*conf->assign_hook) (str, true,
3410                                                                                                    PGC_S_DEFAULT);
3411                                         if (newstr == NULL)
3412                                         {
3413                                                 elog(FATAL, "failed to initialize %s to \"%s\"",
3414                                                          conf->gen.name, str);
3415                                         }
3416                                         else if (newstr != str)
3417                                         {
3418                                                 free(str);
3419
3420                                                 /*
3421                                                  * See notes in set_config_option about casting
3422                                                  */
3423                                                 str = (char *) newstr;
3424                                                 conf->reset_val = str;
3425                                         }
3426                                 }
3427                                 *conf->variable = str;
3428                                 break;
3429                         }
3430                 case PGC_ENUM:
3431                         {
3432                                 struct config_enum *conf = (struct config_enum *) gconf;
3433
3434                                 if (conf->assign_hook)
3435                                         if (!(*conf->assign_hook) (conf->boot_val, true,
3436                                                                                            PGC_S_DEFAULT))
3437                                                 elog(FATAL, "failed to initialize %s to %s",
3438                                                          conf->gen.name,
3439                                                   config_enum_lookup_by_value(conf, conf->boot_val));
3440                                 *conf->variable = conf->reset_val = conf->boot_val;
3441                                 break;
3442                         }
3443         }
3444 }
3445
3446
3447 /*
3448  * Select the configuration files and data directory to be used, and
3449  * do the initial read of postgresql.conf.
3450  *
3451  * This is called after processing command-line switches.
3452  *              userDoption is the -D switch value if any (NULL if unspecified).
3453  *              progname is just for use in error messages.
3454  *
3455  * Returns true on success; on failure, prints a suitable error message
3456  * to stderr and returns false.
3457  */
3458 bool
3459 SelectConfigFiles(const char *userDoption, const char *progname)
3460 {
3461         char       *configdir;
3462         char       *fname;
3463         struct stat stat_buf;
3464
3465         /* configdir is -D option, or $PGDATA if no -D */
3466         if (userDoption)
3467                 configdir = make_absolute_path(userDoption);
3468         else
3469                 configdir = make_absolute_path(getenv("PGDATA"));
3470
3471         /*
3472          * Find the configuration file: if config_file was specified on the
3473          * command line, use it, else use configdir/postgresql.conf.  In any case
3474          * ensure the result is an absolute path, so that it will be interpreted
3475          * the same way by future backends.
3476          */
3477         if (ConfigFileName)
3478                 fname = make_absolute_path(ConfigFileName);
3479         else if (configdir)
3480         {
3481                 fname = guc_malloc(FATAL,
3482                                                    strlen(configdir) + strlen(CONFIG_FILENAME) + 2);
3483                 sprintf(fname, "%s/%s", configdir, CONFIG_FILENAME);
3484         }
3485         else
3486         {
3487                 write_stderr("%s does not know where to find the server configuration file.\n"
3488                                          "You must specify the --config-file or -D invocation "
3489                                          "option or set the PGDATA environment variable.\n",
3490                                          progname);
3491                 return false;
3492         }
3493
3494         /*
3495          * Set the ConfigFileName GUC variable to its final value, ensuring that
3496          * it can't be overridden later.
3497          */
3498         SetConfigOption("config_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3499         free(fname);
3500
3501         /*
3502          * Now read the config file for the first time.
3503          */
3504         if (stat(ConfigFileName, &stat_buf) != 0)
3505         {
3506                 write_stderr("%s cannot access the server configuration file \"%s\": %s\n",
3507                                          progname, ConfigFileName, strerror(errno));
3508                 return false;
3509         }
3510
3511         ProcessConfigFile(PGC_POSTMASTER);
3512
3513         /*
3514          * If the data_directory GUC variable has been set, use that as DataDir;
3515          * otherwise use configdir if set; else punt.
3516          *
3517          * Note: SetDataDir will copy and absolute-ize its argument, so we don't
3518          * have to.
3519          */
3520         if (data_directory)
3521                 SetDataDir(data_directory);
3522         else if (configdir)
3523                 SetDataDir(configdir);
3524         else
3525         {
3526                 write_stderr("%s does not know where to find the database system data.\n"
3527                                          "This can be specified as \"data_directory\" in \"%s\", "
3528                                          "or by the -D invocation option, or by the "
3529                                          "PGDATA environment variable.\n",
3530                                          progname, ConfigFileName);
3531                 return false;
3532         }
3533
3534         /*
3535          * Reflect the final DataDir value back into the data_directory GUC var.
3536          * (If you are wondering why we don't just make them a single variable,
3537          * it's because the EXEC_BACKEND case needs DataDir to be transmitted to
3538          * child backends specially.  XXX is that still true?  Given that we now
3539          * chdir to DataDir, EXEC_BACKEND can read the config file without knowing
3540          * DataDir in advance.)
3541          */
3542         SetConfigOption("data_directory", DataDir, PGC_POSTMASTER, PGC_S_OVERRIDE);
3543
3544         /*
3545          * Figure out where pg_hba.conf is, and make sure the path is absolute.
3546          */
3547         if (HbaFileName)
3548                 fname = make_absolute_path(HbaFileName);
3549         else if (configdir)
3550         {
3551                 fname = guc_malloc(FATAL,
3552                                                    strlen(configdir) + strlen(HBA_FILENAME) + 2);
3553                 sprintf(fname, "%s/%s", configdir, HBA_FILENAME);
3554         }
3555         else
3556         {
3557                 write_stderr("%s does not know where to find the \"hba\" configuration file.\n"
3558                                          "This can be specified as \"hba_file\" in \"%s\", "
3559                                          "or by the -D invocation option, or by the "
3560                                          "PGDATA environment variable.\n",
3561                                          progname, ConfigFileName);
3562                 return false;
3563         }
3564         SetConfigOption("hba_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3565         free(fname);
3566
3567         /*
3568          * Likewise for pg_ident.conf.
3569          */
3570         if (IdentFileName)
3571                 fname = make_absolute_path(IdentFileName);
3572         else if (configdir)
3573         {
3574                 fname = guc_malloc(FATAL,
3575                                                    strlen(configdir) + strlen(IDENT_FILENAME) + 2);
3576                 sprintf(fname, "%s/%s", configdir, IDENT_FILENAME);
3577         }
3578         else
3579         {
3580                 write_stderr("%s does not know where to find the \"ident\" configuration file.\n"
3581                                          "This can be specified as \"ident_file\" in \"%s\", "
3582                                          "or by the -D invocation option, or by the "
3583                                          "PGDATA environment variable.\n",
3584                                          progname, ConfigFileName);
3585                 return false;
3586         }
3587         SetConfigOption("ident_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3588         free(fname);
3589
3590         free(configdir);
3591
3592         return true;
3593 }
3594
3595
3596 /*
3597  * Reset all options to their saved default values (implements RESET ALL)
3598  */
3599 void
3600 ResetAllOptions(void)
3601 {
3602         int                     i;
3603
3604         for (i = 0; i < num_guc_variables; i++)
3605         {
3606                 struct config_generic *gconf = guc_variables[i];
3607
3608                 /* Don't reset non-SET-able values */
3609                 if (gconf->context != PGC_SUSET &&
3610                         gconf->context != PGC_USERSET)
3611                         continue;
3612                 /* Don't reset if special exclusion from RESET ALL */
3613                 if (gconf->flags & GUC_NO_RESET_ALL)
3614                         continue;
3615                 /* No need to reset if wasn't SET */
3616                 if (gconf->source <= PGC_S_OVERRIDE)
3617                         continue;
3618
3619                 /* Save old value to support transaction abort */
3620                 push_old_value(gconf, GUC_ACTION_SET);
3621
3622                 switch (gconf->vartype)
3623                 {
3624                         case PGC_BOOL:
3625                                 {
3626                                         struct config_bool *conf = (struct config_bool *) gconf;
3627
3628                                         if (conf->assign_hook)
3629                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3630                                                                                                    PGC_S_SESSION))
3631                                                         elog(ERROR, "failed to reset %s to %d",
3632                                                                  conf->gen.name, (int) conf->reset_val);
3633                                         *conf->variable = conf->reset_val;
3634                                         break;
3635                                 }
3636                         case PGC_INT:
3637                                 {
3638                                         struct config_int *conf = (struct config_int *) gconf;
3639
3640                                         if (conf->assign_hook)
3641                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3642                                                                                                    PGC_S_SESSION))
3643                                                         elog(ERROR, "failed to reset %s to %d",
3644                                                                  conf->gen.name, conf->reset_val);
3645                                         *conf->variable = conf->reset_val;
3646                                         break;
3647                                 }
3648                         case PGC_REAL:
3649                                 {
3650                                         struct config_real *conf = (struct config_real *) gconf;
3651
3652                                         if (conf->assign_hook)
3653                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3654                                                                                                    PGC_S_SESSION))
3655                                                         elog(ERROR, "failed to reset %s to %g",
3656                                                                  conf->gen.name, conf->reset_val);
3657                                         *conf->variable = conf->reset_val;
3658                                         break;
3659                                 }
3660                         case PGC_STRING:
3661                                 {
3662                                         struct config_string *conf = (struct config_string *) gconf;
3663                                         char       *str;
3664
3665                                         /* We need not strdup here */
3666                                         str = conf->reset_val;
3667
3668                                         if (conf->assign_hook && str)
3669                                         {
3670                                                 const char *newstr;
3671
3672                                                 newstr = (*conf->assign_hook) (str, true,
3673                                                                                                            PGC_S_SESSION);
3674                                                 if (newstr == NULL)
3675                                                         elog(ERROR, "failed to reset %s to \"%s\"",
3676                                                                  conf->gen.name, str);
3677                                                 else if (newstr != str)
3678                                                 {
3679                                                         /*
3680                                                          * See notes in set_config_option about casting
3681                                                          */
3682                                                         str = (char *) newstr;
3683                                                 }
3684                                         }
3685
3686                                         set_string_field(conf, conf->variable, str);
3687                                         break;
3688                                 }
3689                         case PGC_ENUM:
3690                                 {
3691                                         struct config_enum *conf = (struct config_enum *) gconf;
3692
3693                                         if (conf->assign_hook)
3694                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3695                                                                                                    PGC_S_SESSION))
3696                                                         elog(ERROR, "failed to reset %s to %s",
3697                                                                  conf->gen.name,
3698                                                                  config_enum_lookup_by_value(conf, conf->reset_val));
3699                                         *conf->variable = conf->reset_val;
3700                                         break;
3701                                 }
3702                 }
3703
3704                 gconf->source = gconf->reset_source;
3705
3706                 if (gconf->flags & GUC_REPORT)
3707                         ReportGUCOption(gconf);
3708         }
3709 }
3710
3711
3712 /*
3713  * push_old_value
3714  *              Push previous state during transactional assignment to a GUC variable.
3715  */
3716 static void
3717 push_old_value(struct config_generic * gconf, GucAction action)
3718 {
3719         GucStack   *stack;
3720
3721         /* If we're not inside a nest level, do nothing */
3722         if (GUCNestLevel == 0)
3723                 return;
3724
3725         /* Do we already have a stack entry of the current nest level? */
3726         stack = gconf->stack;
3727         if (stack && stack->nest_level >= GUCNestLevel)
3728         {
3729                 /* Yes, so adjust its state if necessary */
3730                 Assert(stack->nest_level == GUCNestLevel);
3731                 switch (action)
3732                 {
3733                         case GUC_ACTION_SET:
3734                                 /* SET overrides any prior action at same nest level */
3735                                 if (stack->state == GUC_SET_LOCAL)
3736                                 {
3737                                         /* must discard old masked value */
3738                                         discard_stack_value(gconf, &stack->masked);
3739                                 }
3740                                 stack->state = GUC_SET;
3741                                 break;
3742                         case GUC_ACTION_LOCAL:
3743                                 if (stack->state == GUC_SET)
3744                                 {
3745                                         /* SET followed by SET LOCAL, remember SET's value */
3746                                         set_stack_value(gconf, &stack->masked);
3747                                         stack->state = GUC_SET_LOCAL;
3748                                 }
3749                                 /* in all other cases, no change to stack entry */
3750                                 break;
3751                         case GUC_ACTION_SAVE:
3752                                 /* Could only have a prior SAVE of same variable */
3753                                 Assert(stack->state == GUC_SAVE);
3754                                 break;
3755                 }
3756                 Assert(guc_dirty);              /* must be set already */
3757                 return;
3758         }
3759
3760         /*
3761          * Push a new stack entry
3762          *
3763          * We keep all the stack entries in TopTransactionContext for simplicity.
3764          */
3765         stack = (GucStack *) MemoryContextAllocZero(TopTransactionContext,
3766                                                                                                 sizeof(GucStack));
3767
3768         stack->prev = gconf->stack;
3769         stack->nest_level = GUCNestLevel;
3770         switch (action)
3771         {
3772                 case GUC_ACTION_SET:
3773                         stack->state = GUC_SET;
3774                         break;
3775                 case GUC_ACTION_LOCAL:
3776                         stack->state = GUC_LOCAL;
3777                         break;
3778                 case GUC_ACTION_SAVE:
3779                         stack->state = GUC_SAVE;
3780                         break;
3781         }
3782         stack->source = gconf->source;
3783         set_stack_value(gconf, &stack->prior);
3784
3785         gconf->stack = stack;
3786
3787         /* Ensure we remember to pop at end of xact */
3788         guc_dirty = true;
3789 }
3790
3791
3792 /*
3793  * Do GUC processing at main transaction start.
3794  */
3795 void
3796 AtStart_GUC(void)
3797 {
3798         /*
3799          * The nest level should be 0 between transactions; if it isn't, somebody
3800          * didn't call AtEOXact_GUC, or called it with the wrong nestLevel.  We
3801          * throw a warning but make no other effort to clean up.
3802          */
3803         if (GUCNestLevel != 0)
3804                 elog(WARNING, "GUC nest level = %d at transaction start",
3805                          GUCNestLevel);
3806         GUCNestLevel = 1;
3807 }
3808
3809 /*
3810  * Enter a new nesting level for GUC values.  This is called at subtransaction
3811  * start and when entering a function that has proconfig settings.      NOTE that
3812  * we must not risk error here, else subtransaction start will be unhappy.
3813  */
3814 int
3815 NewGUCNestLevel(void)
3816 {
3817         return ++GUCNestLevel;
3818 }
3819
3820 /*
3821  * Do GUC processing at transaction or subtransaction commit or abort, or
3822  * when exiting a function that has proconfig settings.  (The name is thus
3823  * a bit of a misnomer; perhaps it should be ExitGUCNestLevel or some such.)
3824  * During abort, we discard all GUC settings that were applied at nesting
3825  * levels >= nestLevel.  nestLevel == 1 corresponds to the main transaction.
3826  */
3827 void
3828 AtEOXact_GUC(bool isCommit, int nestLevel)
3829 {
3830         bool            still_dirty;
3831         int                     i;
3832
3833         Assert(nestLevel > 0 && nestLevel <= GUCNestLevel);
3834
3835         /* Quick exit if nothing's changed in this transaction */
3836         if (!guc_dirty)
3837         {
3838                 GUCNestLevel = nestLevel - 1;
3839                 return;
3840         }
3841
3842         still_dirty = false;
3843         for (i = 0; i < num_guc_variables; i++)
3844         {
3845                 struct config_generic *gconf = guc_variables[i];
3846                 GucStack   *stack;
3847
3848                 /*
3849                  * Process and pop each stack entry within the nest level.      To
3850                  * simplify fmgr_security_definer(), we allow failure exit from a
3851                  * function-with-SET-options to be recovered at the surrounding
3852                  * transaction or subtransaction abort; so there could be more than
3853                  * one stack entry to pop.
3854                  */
3855                 while ((stack = gconf->stack) != NULL &&
3856                            stack->nest_level >= nestLevel)
3857                 {
3858                         GucStack   *prev = stack->prev;
3859                         bool            restorePrior = false;
3860                         bool            restoreMasked = false;
3861                         bool            changed;
3862
3863                         /*
3864                          * In this next bit, if we don't set either restorePrior or
3865                          * restoreMasked, we must "discard" any unwanted fields of the
3866                          * stack entries to avoid leaking memory.  If we do set one of
3867                          * those flags, unused fields will be cleaned up after restoring.
3868                          */
3869                         if (!isCommit)          /* if abort, always restore prior value */
3870                                 restorePrior = true;
3871                         else if (stack->state == GUC_SAVE)
3872                                 restorePrior = true;
3873                         else if (stack->nest_level == 1)
3874                         {
3875                                 /* transaction commit */
3876                                 if (stack->state == GUC_SET_LOCAL)
3877                                         restoreMasked = true;
3878                                 else if (stack->state == GUC_SET)
3879                                 {
3880                                         /* we keep the current active value */
3881                                         discard_stack_value(gconf, &stack->prior);
3882                                 }
3883                                 else    /* must be GUC_LOCAL */
3884                                         restorePrior = true;
3885                         }
3886                         else if (prev == NULL ||
3887                                          prev->nest_level < stack->nest_level - 1)
3888                         {
3889                                 /* decrement entry's level and do not pop it */
3890                                 stack->nest_level--;
3891                                 continue;
3892                         }
3893                         else
3894                         {
3895                                 /*
3896                                  * We have to merge this stack entry into prev. See README for
3897                                  * discussion of this bit.
3898                                  */
3899                                 switch (stack->state)
3900                                 {
3901                                         case GUC_SAVE:
3902                                                 Assert(false);  /* can't get here */
3903
3904                                         case GUC_SET:
3905                                                 /* next level always becomes SET */
3906                                                 discard_stack_value(gconf, &stack->prior);
3907                                                 if (prev->state == GUC_SET_LOCAL)
3908                                                         discard_stack_value(gconf, &prev->masked);
3909                                                 prev->state = GUC_SET;
3910                                                 break;
3911
3912                                         case GUC_LOCAL:
3913                                                 if (prev->state == GUC_SET)
3914                                                 {
3915                                                         /* LOCAL migrates down */
3916                                                         prev->masked = stack->prior;
3917                                                         prev->state = GUC_SET_LOCAL;
3918                                                 }
3919                                                 else
3920                                                 {
3921                                                         /* else just forget this stack level */
3922                                                         discard_stack_value(gconf, &stack->prior);
3923                                                 }
3924                                                 break;
3925
3926                                         case GUC_SET_LOCAL:
3927                                                 /* prior state at this level no longer wanted */
3928                                                 discard_stack_value(gconf, &stack->prior);
3929                                                 /* copy down the masked state */
3930                                                 if (prev->state == GUC_SET_LOCAL)
3931                                                         discard_stack_value(gconf, &prev->masked);
3932                                                 prev->masked = stack->masked;
3933                                                 prev->state = GUC_SET_LOCAL;
3934                                                 break;
3935                                 }
3936                         }
3937
3938                         changed = false;
3939
3940                         if (restorePrior || restoreMasked)
3941                         {
3942                                 /* Perform appropriate restoration of the stacked value */
3943                                 union config_var_value newvalue;
3944                                 GucSource       newsource;
3945
3946                                 if (restoreMasked)
3947                                 {
3948                                         newvalue = stack->masked;
3949                                         newsource = PGC_S_SESSION;
3950                                 }
3951                                 else
3952                                 {
3953                                         newvalue = stack->prior;
3954                                         newsource = stack->source;
3955                                 }
3956
3957                                 switch (gconf->vartype)
3958                                 {
3959                                         case PGC_BOOL:
3960                                                 {
3961                                                         struct config_bool *conf = (struct config_bool *) gconf;
3962                                                         bool            newval = newvalue.boolval;
3963
3964                                                         if (*conf->variable != newval)
3965                                                         {
3966                                                                 if (conf->assign_hook)
3967                                                                         if (!(*conf->assign_hook) (newval,
3968                                                                                                            true, PGC_S_OVERRIDE))
3969                                                                                 elog(LOG, "failed to commit %s as %d",
3970                                                                                          conf->gen.name, (int) newval);
3971                                                                 *conf->variable = newval;
3972                                                                 changed = true;
3973                                                         }
3974                                                         break;
3975                                                 }
3976                                         case PGC_INT:
3977                                                 {
3978                                                         struct config_int *conf = (struct config_int *) gconf;
3979                                                         int                     newval = newvalue.intval;
3980
3981                                                         if (*conf->variable != newval)
3982                                                         {
3983                                                                 if (conf->assign_hook)
3984                                                                         if (!(*conf->assign_hook) (newval,
3985                                                                                                            true, PGC_S_OVERRIDE))
3986                                                                                 elog(LOG, "failed to commit %s as %d",
3987                                                                                          conf->gen.name, newval);
3988                                                                 *conf->variable = newval;
3989                                                                 changed = true;
3990                                                         }
3991                                                         break;
3992                                                 }
3993                                         case PGC_REAL:
3994                                                 {
3995                                                         struct config_real *conf = (struct config_real *) gconf;
3996                                                         double          newval = newvalue.realval;
3997
3998                                                         if (*conf->variable != newval)
3999                                                         {
4000                                                                 if (conf->assign_hook)
4001                                                                         if (!(*conf->assign_hook) (newval,
4002                                                                                                            true, PGC_S_OVERRIDE))
4003                                                                                 elog(LOG, "failed to commit %s as %g",
4004                                                                                          conf->gen.name, newval);
4005                                                                 *conf->variable = newval;
4006                                                                 changed = true;
4007                                                         }
4008                                                         break;
4009                                                 }
4010                                         case PGC_STRING:
4011                                                 {
4012                                                         struct config_string *conf = (struct config_string *) gconf;
4013                                                         char       *newval = newvalue.stringval;
4014
4015                                                         if (*conf->variable != newval)
4016                                                         {
4017                                                                 if (conf->assign_hook && newval)
4018                                                                 {
4019                                                                         const char *newstr;
4020
4021                                                                         newstr = (*conf->assign_hook) (newval, true,
4022                                                                                                                          PGC_S_OVERRIDE);
4023                                                                         if (newstr == NULL)
4024                                                                                 elog(LOG, "failed to commit %s as \"%s\"",
4025                                                                                          conf->gen.name, newval);
4026                                                                         else if (newstr != newval)
4027                                                                         {
4028                                                                                 /*
4029                                                                                  * If newval should now be freed,
4030                                                                                  * it'll be taken care of below.
4031                                                                                  *
4032                                                                                  * See notes in set_config_option
4033                                                                                  * about casting
4034                                                                                  */
4035                                                                                 newval = (char *) newstr;
4036                                                                         }
4037                                                                 }
4038
4039                                                                 set_string_field(conf, conf->variable, newval);
4040                                                                 changed = true;
4041                                                         }
4042
4043                                                         /*
4044                                                          * Release stacked values if not used anymore. We
4045                                                          * could use discard_stack_value() here, but since
4046                                                          * we have type-specific code anyway, might as
4047                                                          * well inline it.
4048                                                          */
4049                                                         set_string_field(conf, &stack->prior.stringval, NULL);
4050                                                         set_string_field(conf, &stack->masked.stringval, NULL);
4051                                                         break;
4052                                                 }
4053                                         case PGC_ENUM:
4054                                                 {
4055                                                         struct config_enum *conf = (struct config_enum *) gconf;
4056                                                         int                     newval = newvalue.enumval;
4057
4058                                                         if (*conf->variable != newval)
4059                                                         {
4060                                                                 if (conf->assign_hook)
4061                                                                         if (!(*conf->assign_hook) (newval,
4062                                                                                                            true, PGC_S_OVERRIDE))
4063                                                                                 elog(LOG, "failed to commit %s as %s",
4064                                                                                          conf->gen.name,
4065                                                                                          config_enum_lookup_by_value(conf, newval));
4066                                                                 *conf->variable = newval;
4067                                                                 changed = true;
4068                                                         }
4069                                                         break;
4070                                                 }
4071                                 }
4072
4073                                 gconf->source = newsource;
4074                         }
4075
4076                         /* Finish popping the state stack */
4077                         gconf->stack = prev;
4078                         pfree(stack);
4079
4080                         /* Report new value if we changed it */
4081                         if (changed && (gconf->flags & GUC_REPORT))
4082                                 ReportGUCOption(gconf);
4083                 }                                               /* end of stack-popping loop */
4084
4085                 if (stack != NULL)
4086                         still_dirty = true;
4087         }
4088
4089         /* If there are no remaining stack entries, we can reset guc_dirty */
4090         guc_dirty = still_dirty;
4091
4092         /* Update nesting level */
4093         GUCNestLevel = nestLevel - 1;
4094 }
4095
4096
4097 /*
4098  * Start up automatic reporting of changes to variables marked GUC_REPORT.
4099  * This is executed at completion of backend startup.
4100  */
4101 void
4102 BeginReportingGUCOptions(void)
4103 {
4104         int                     i;
4105
4106         /*
4107          * Don't do anything unless talking to an interactive frontend of protocol
4108          * 3.0 or later.
4109          */
4110         if (whereToSendOutput != DestRemote ||
4111                 PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
4112                 return;
4113
4114         reporting_enabled = true;
4115
4116         /* Transmit initial values of interesting variables */
4117         for (i = 0; i < num_guc_variables; i++)
4118         {
4119                 struct config_generic *conf = guc_variables[i];
4120
4121                 if (conf->flags & GUC_REPORT)
4122                         ReportGUCOption(conf);
4123         }
4124 }
4125
4126 /*
4127  * ReportGUCOption: if appropriate, transmit option value to frontend
4128  */
4129 static void
4130 ReportGUCOption(struct config_generic * record)
4131 {
4132         if (reporting_enabled && (record->flags & GUC_REPORT))
4133         {
4134                 char       *val = _ShowOption(record, false);
4135                 StringInfoData msgbuf;
4136
4137                 pq_beginmessage(&msgbuf, 'S');
4138                 pq_sendstring(&msgbuf, record->name);
4139                 pq_sendstring(&msgbuf, val);
4140                 pq_endmessage(&msgbuf);
4141
4142                 pfree(val);
4143         }
4144 }
4145
4146 /*
4147  * Try to parse value as an integer.  The accepted formats are the
4148  * usual decimal, octal, or hexadecimal formats, optionally followed by
4149  * a unit name if "flags" indicates a unit is allowed.
4150  *
4151  * If the string parses okay, return true, else false.
4152  * If okay and result is not NULL, return the value in *result.
4153  * If not okay and hintmsg is not NULL, *hintmsg is set to a suitable
4154  *      HINT message, or NULL if no hint provided.
4155  */
4156 bool
4157 parse_int(const char *value, int *result, int flags, const char **hintmsg)
4158 {
4159         int64           val;
4160         char       *endptr;
4161
4162         /* To suppress compiler warnings, always set output params */
4163         if (result)
4164                 *result = 0;
4165         if (hintmsg)
4166                 *hintmsg = NULL;
4167
4168         /* We assume here that int64 is at least as wide as long */
4169         errno = 0;
4170         val = strtol(value, &endptr, 0);
4171
4172         if (endptr == value)
4173                 return false;                   /* no HINT for integer syntax error */
4174
4175         if (errno == ERANGE || val != (int64) ((int32) val))
4176         {
4177                 if (hintmsg)
4178                         *hintmsg = gettext_noop("Value exceeds integer range.");
4179                 return false;
4180         }
4181
4182         /* allow whitespace between integer and unit */
4183         while (isspace((unsigned char) *endptr))
4184                 endptr++;
4185
4186         /* Handle possible unit */
4187         if (*endptr != '\0')
4188         {
4189                 /*
4190                  * Note: the multiple-switch coding technique here is a bit tedious,
4191                  * but seems necessary to avoid intermediate-value overflows.
4192                  *
4193                  * If INT64_IS_BUSTED (ie, it's really int32) we will fail to detect
4194                  * overflow due to units conversion, but there are few enough such
4195                  * machines that it does not seem worth trying to be smarter.
4196                  */
4197                 if (flags & GUC_UNIT_MEMORY)
4198                 {
4199                         /* Set hint for use if no match or trailing garbage */
4200                         if (hintmsg)
4201                                 *hintmsg = gettext_noop("Valid units for this parameter are \"kB\", \"MB\", and \"GB\".");
4202
4203 #if BLCKSZ < 1024 || BLCKSZ > (1024*1024)
4204 #error BLCKSZ must be between 1KB and 1MB
4205 #endif
4206 #if XLOG_BLCKSZ < 1024 || XLOG_BLCKSZ > (1024*1024)
4207 #error XLOG_BLCKSZ must be between 1KB and 1MB
4208 #endif
4209
4210                         if (strncmp(endptr, "kB", 2) == 0)
4211                         {
4212                                 endptr += 2;
4213                                 switch (flags & GUC_UNIT_MEMORY)
4214                                 {
4215                                         case GUC_UNIT_BLOCKS:
4216                                                 val /= (BLCKSZ / 1024);
4217                                                 break;
4218                                         case GUC_UNIT_XBLOCKS:
4219                                                 val /= (XLOG_BLCKSZ / 1024);
4220                                                 break;
4221                                 }
4222                         }
4223                         else if (strncmp(endptr, "MB", 2) == 0)
4224                         {
4225                                 endptr += 2;
4226                                 switch (flags & GUC_UNIT_MEMORY)
4227                                 {
4228                                         case GUC_UNIT_KB:
4229                                                 val *= KB_PER_MB;
4230                                                 break;
4231                                         case GUC_UNIT_BLOCKS:
4232                                                 val *= KB_PER_MB / (BLCKSZ / 1024);
4233                                                 break;
4234                                         case GUC_UNIT_XBLOCKS:
4235                                                 val *= KB_PER_MB / (XLOG_BLCKSZ / 1024);
4236                                                 break;
4237                                 }
4238                         }
4239                         else if (strncmp(endptr, "GB", 2) == 0)
4240                         {
4241                                 endptr += 2;
4242                                 switch (flags & GUC_UNIT_MEMORY)
4243                                 {
4244                                         case GUC_UNIT_KB:
4245                                                 val *= KB_PER_GB;
4246                                                 break;
4247                                         case GUC_UNIT_BLOCKS:
4248                                                 val *= KB_PER_GB / (BLCKSZ / 1024);
4249                                                 break;
4250                                         case GUC_UNIT_XBLOCKS:
4251                                                 val *= KB_PER_GB / (XLOG_BLCKSZ / 1024);
4252                                                 break;
4253                                 }
4254                         }
4255                 }
4256                 else if (flags & GUC_UNIT_TIME)
4257                 {
4258                         /* Set hint for use if no match or trailing garbage */
4259                         if (hintmsg)
4260                                 *hintmsg = gettext_noop("Valid units for this parameter are \"ms\", \"s\", \"min\", \"h\", and \"d\".");
4261
4262                         if (strncmp(endptr, "ms", 2) == 0)
4263                         {
4264                                 endptr += 2;
4265                                 switch (flags & GUC_UNIT_TIME)
4266                                 {
4267                                         case GUC_UNIT_S:
4268                                                 val /= MS_PER_S;
4269                                                 break;
4270                                         case GUC_UNIT_MIN:
4271                                                 val /= MS_PER_MIN;
4272                                                 break;
4273                                 }
4274                         }
4275                         else if (strncmp(endptr, "s", 1) == 0)
4276                         {
4277                                 endptr += 1;
4278                                 switch (flags & GUC_UNIT_TIME)
4279                                 {
4280                                         case GUC_UNIT_MS:
4281                                                 val *= MS_PER_S;
4282                                                 break;
4283                                         case GUC_UNIT_MIN:
4284                                                 val /= S_PER_MIN;
4285                                                 break;
4286                                 }
4287                         }
4288                         else if (strncmp(endptr, "min", 3) == 0)
4289                         {
4290                                 endptr += 3;
4291                                 switch (flags & GUC_UNIT_TIME)
4292                                 {
4293                                         case GUC_UNIT_MS:
4294                                                 val *= MS_PER_MIN;
4295                                                 break;
4296                                         case GUC_UNIT_S:
4297                                                 val *= S_PER_MIN;
4298                                                 break;
4299                                 }
4300                         }
4301                         else if (strncmp(endptr, "h", 1) == 0)
4302                         {
4303                                 endptr += 1;
4304                                 switch (flags & GUC_UNIT_TIME)
4305                                 {
4306                                         case GUC_UNIT_MS:
4307                                                 val *= MS_PER_H;
4308                                                 break;
4309                                         case GUC_UNIT_S:
4310                                                 val *= S_PER_H;
4311                                                 break;
4312                                         case GUC_UNIT_MIN:
4313                                                 val *= MIN_PER_H;
4314                                                 break;
4315                                 }
4316                         }
4317                         else if (strncmp(endptr, "d", 1) == 0)
4318                         {
4319                                 endptr += 1;
4320                                 switch (flags & GUC_UNIT_TIME)
4321                                 {
4322                                         case GUC_UNIT_MS:
4323                                                 val *= MS_PER_D;
4324                                                 break;
4325                                         case GUC_UNIT_S:
4326                                                 val *= S_PER_D;
4327                                                 break;
4328                                         case GUC_UNIT_MIN:
4329                                                 val *= MIN_PER_D;
4330                                                 break;
4331                                 }
4332                         }
4333                 }
4334
4335                 /* allow whitespace after unit */
4336                 while (isspace((unsigned char) *endptr))
4337                         endptr++;
4338
4339                 if (*endptr != '\0')
4340                         return false;           /* appropriate hint, if any, already set */
4341
4342                 /* Check for overflow due to units conversion */
4343                 if (val != (int64) ((int32) val))
4344                 {
4345                         if (hintmsg)
4346                                 *hintmsg = gettext_noop("Value exceeds integer range.");
4347                         return false;
4348                 }
4349         }
4350
4351         if (result)
4352                 *result = (int) val;
4353         return true;
4354 }
4355
4356
4357
4358 /*
4359  * Try to parse value as a floating point number in the usual format.
4360  * If the string parses okay, return true, else false.
4361  * If okay and result is not NULL, return the value in *result.
4362  */
4363 bool
4364 parse_real(const char *value, double *result)
4365 {
4366         double          val;
4367         char       *endptr;
4368
4369         if (result)
4370                 *result = 0;                    /* suppress compiler warning */
4371
4372         errno = 0;
4373         val = strtod(value, &endptr);
4374         if (endptr == value || errno == ERANGE)
4375                 return false;
4376
4377         /* allow whitespace after number */
4378         while (isspace((unsigned char) *endptr))
4379                 endptr++;
4380         if (*endptr != '\0')
4381                 return false;
4382
4383         if (result)
4384                 *result = val;
4385         return true;
4386 }
4387
4388
4389 /*
4390  * Lookup the name for an enum option with the selected value.
4391  * Should only ever be called with known-valid values, so throws
4392  * an elog(ERROR) if the enum option is not found.
4393  *
4394  * The returned string is a pointer to static data and not
4395  * allocated for modification.
4396  */
4397 const char *
4398 config_enum_lookup_by_value(struct config_enum * record, int val)
4399 {
4400         const struct config_enum_entry *entry;
4401
4402         for (entry = record->options; entry && entry->name; entry++)
4403         {
4404                 if (entry->val == val)
4405                         return entry->name;
4406         }
4407
4408         elog(ERROR, "could not find enum option %d for %s",
4409                  val, record->gen.name);
4410         return NULL;                            /* silence compiler */
4411 }
4412
4413
4414 /*
4415  * Lookup the value for an enum option with the selected name
4416  * (case-insensitive).
4417  * If the enum option is found, sets the retval value and returns
4418  * true. If it's not found, return FALSE and retval is set to 0.
4419  */
4420 bool
4421 config_enum_lookup_by_name(struct config_enum * record, const char *value,
4422                                                    int *retval)
4423 {
4424         const struct config_enum_entry *entry;
4425
4426         for (entry = record->options; entry && entry->name; entry++)
4427         {
4428                 if (pg_strcasecmp(value, entry->name) == 0)
4429                 {
4430                         *retval = entry->val;
4431                         return TRUE;
4432                 }
4433         }
4434
4435         *retval = 0;
4436         return FALSE;
4437 }
4438
4439
4440 /*
4441  * Return a list of all available options for an enum, excluding
4442  * hidden ones, separated by the given separator.
4443  * If prefix is non-NULL, it is added before the first enum value.
4444  * If suffix is non-NULL, it is added to the end of the string.
4445  */
4446 static char *
4447 config_enum_get_options(struct config_enum * record, const char *prefix,
4448                                                 const char *suffix, const char *separator)
4449 {
4450         const struct config_enum_entry *entry;
4451         StringInfoData retstr;
4452         int                     seplen;
4453
4454         initStringInfo(&retstr);
4455         appendStringInfoString(&retstr, prefix);
4456
4457         seplen = strlen(separator);
4458         for (entry = record->options; entry && entry->name; entry++)
4459         {
4460                 if (!entry->hidden)
4461                 {
4462                         appendStringInfoString(&retstr, entry->name);
4463                         appendBinaryStringInfo(&retstr, separator, seplen);
4464                 }
4465         }
4466
4467         /*
4468          * All the entries may have been hidden, leaving the string empty if no
4469          * prefix was given. This indicates a broken GUC setup, since there is no
4470          * use for an enum without any values, so we just check to make sure we
4471          * don't write to invalid memory instead of actually trying to do
4472          * something smart with it.
4473          */
4474         if (retstr.len >= seplen)
4475         {
4476                 /* Replace final separator */
4477                 retstr.data[retstr.len - seplen] = '\0';
4478                 retstr.len -= seplen;
4479         }
4480
4481         appendStringInfoString(&retstr, suffix);
4482
4483         return retstr.data;
4484 }
4485
4486 /*
4487  * Call a GucStringAssignHook function, being careful to free the
4488  * "newval" string if the hook ereports.
4489  *
4490  * This is split out of set_config_option just to avoid the "volatile"
4491  * qualifiers that would otherwise have to be plastered all over.
4492  */
4493 static const char *
4494 call_string_assign_hook(GucStringAssignHook assign_hook,
4495                                                 char *newval, bool doit, GucSource source)
4496 {
4497         const char *result;
4498
4499         PG_TRY();
4500         {
4501                 result = (*assign_hook) (newval, doit, source);
4502         }
4503         PG_CATCH();
4504         {
4505                 free(newval);
4506                 PG_RE_THROW();
4507         }
4508         PG_END_TRY();
4509
4510         return result;
4511 }
4512
4513
4514 /*
4515  * Sets option `name' to given value. The value should be a string
4516  * which is going to be parsed and converted to the appropriate data
4517  * type.  The context and source parameters indicate in which context this
4518  * function is being called so it can apply the access restrictions
4519  * properly.
4520  *
4521  * If value is NULL, set the option to its default value (normally the
4522  * reset_val, but if source == PGC_S_DEFAULT we instead use the boot_val).
4523  *
4524  * action indicates whether to set the value globally in the session, locally
4525  * to the current top transaction, or just for the duration of a function call.
4526  *
4527  * If changeVal is false then don't really set the option but do all
4528  * the checks to see if it would work.
4529  *
4530  * If there is an error (non-existing option, invalid value) then an
4531  * ereport(ERROR) is thrown *unless* this is called in a context where we
4532  * don't want to ereport (currently, startup or SIGHUP config file reread).
4533  * In that case we write a suitable error message via ereport(LOG) and
4534  * return false. This is working around the deficiencies in the ereport
4535  * mechanism, so don't blame me.  In all other cases, the function
4536  * returns true, including cases where the input is valid but we chose
4537  * not to apply it because of context or source-priority considerations.
4538  *
4539  * See also SetConfigOption for an external interface.
4540  */
4541 bool
4542 set_config_option(const char *name, const char *value,
4543                                   GucContext context, GucSource source,
4544                                   GucAction action, bool changeVal)
4545 {
4546         struct config_generic *record;
4547         int                     elevel;
4548         bool            makeDefault;
4549
4550         if (context == PGC_SIGHUP || source == PGC_S_DEFAULT)
4551         {
4552                 /*
4553                  * To avoid cluttering the log, only the postmaster bleats loudly
4554                  * about problems with the config file.
4555                  */
4556                 elevel = IsUnderPostmaster ? DEBUG3 : LOG;
4557         }
4558         else if (source == PGC_S_DATABASE || source == PGC_S_USER ||
4559                          source == PGC_S_DATABASE_USER)
4560                 elevel = WARNING;
4561         else
4562                 elevel = ERROR;
4563
4564         record = find_option(name, true, elevel);
4565         if (record == NULL)
4566         {
4567                 ereport(elevel,
4568                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
4569                            errmsg("unrecognized configuration parameter \"%s\"", name)));
4570                 return false;
4571         }
4572
4573         /*
4574          * If source is postgresql.conf, mark the found record with
4575          * GUC_IS_IN_FILE. This is for the convenience of ProcessConfigFile.  Note
4576          * that we do it even if changeVal is false, since ProcessConfigFile wants
4577          * the marking to occur during its testing pass.
4578          */
4579         if (source == PGC_S_FILE)
4580                 record->status |= GUC_IS_IN_FILE;
4581
4582         /*
4583          * Check if the option can be set at this time. See guc.h for the precise
4584          * rules. Note that we don't want to throw errors if we're in the SIGHUP
4585          * context. In that case we just ignore the attempt and return true.
4586          */
4587         switch (record->context)
4588         {
4589                 case PGC_INTERNAL:
4590                         if (context == PGC_SIGHUP)
4591                                 return true;
4592                         if (context != PGC_INTERNAL)
4593                         {
4594                                 ereport(elevel,
4595                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4596                                                  errmsg("parameter \"%s\" cannot be changed",
4597                                                                 name)));
4598                                 return false;
4599                         }
4600                         break;
4601                 case PGC_POSTMASTER:
4602                         if (context == PGC_SIGHUP)
4603                         {
4604                                 /*
4605                                  * We are reading a PGC_POSTMASTER var from postgresql.conf.
4606                                  * We can't change the setting, so give a warning if the DBA
4607                                  * tries to change it.  (Throwing an error would be more
4608                                  * consistent, but seems overly rigid.)
4609                                  */
4610                                 if (changeVal && !is_newvalue_equal(record, value))
4611                                         ereport(elevel,
4612                                                         (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4613                                            errmsg("parameter \"%s\" cannot be changed without restarting the server",
4614                                                           name)));
4615                                 return true;
4616                         }
4617                         if (context != PGC_POSTMASTER)
4618                         {
4619                                 ereport(elevel,
4620                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4621                                            errmsg("parameter \"%s\" cannot be changed without restarting the server",
4622                                                           name)));
4623                                 return false;
4624                         }
4625                         break;
4626                 case PGC_SIGHUP:
4627                         if (context != PGC_SIGHUP && context != PGC_POSTMASTER)
4628                         {
4629                                 ereport(elevel,
4630                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4631                                                  errmsg("parameter \"%s\" cannot be changed now",
4632                                                                 name)));
4633                                 return false;
4634                         }
4635
4636                         /*
4637                          * Hmm, the idea of the SIGHUP context is "ought to be global, but
4638                          * can be changed after postmaster start". But there's nothing
4639                          * that prevents a crafty administrator from sending SIGHUP
4640                          * signals to individual backends only.
4641                          */
4642                         break;
4643                 case PGC_BACKEND:
4644                         if (context == PGC_SIGHUP)
4645                         {
4646                                 /*
4647                                  * If a PGC_BACKEND parameter is changed in the config file,
4648                                  * we want to accept the new value in the postmaster (whence
4649                                  * it will propagate to subsequently-started backends), but
4650                                  * ignore it in existing backends.      This is a tad klugy, but
4651                                  * necessary because we don't re-read the config file during
4652                                  * backend start.
4653                                  */
4654                                 if (IsUnderPostmaster)
4655                                         return true;
4656                         }
4657                         else if (context != PGC_POSTMASTER && context != PGC_BACKEND &&
4658                                          source != PGC_S_CLIENT)
4659                         {
4660                                 ereport(elevel,
4661                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4662                                                  errmsg("parameter \"%s\" cannot be set after connection start",
4663                                                                 name)));
4664                                 return false;
4665                         }
4666                         break;
4667                 case PGC_SUSET:
4668                         if (context == PGC_USERSET || context == PGC_BACKEND)
4669                         {
4670                                 ereport(elevel,
4671                                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
4672                                                  errmsg("permission denied to set parameter \"%s\"",
4673                                                                 name)));
4674                                 return false;
4675                         }
4676                         break;
4677                 case PGC_USERSET:
4678                         /* always okay */
4679                         break;
4680         }
4681
4682         /*
4683          * Disallow changing GUC_NOT_WHILE_SEC_REST values if we are inside a
4684          * security restriction context.  We can reject this regardless of
4685          * the GUC context or source, mainly because sources that it might be
4686          * reasonable to override for won't be seen while inside a function.
4687          *
4688          * Note: variables marked GUC_NOT_WHILE_SEC_REST should usually be marked
4689          * GUC_NO_RESET_ALL as well, because ResetAllOptions() doesn't check this.
4690          * An exception might be made if the reset value is assumed to be "safe".
4691          *
4692          * Note: this flag is currently used for "session_authorization" and
4693          * "role".  We need to prohibit changing these inside a local userid
4694          * context because when we exit it, GUC won't be notified, leaving things
4695          * out of sync.  (This could be fixed by forcing a new GUC nesting level,
4696          * but that would change behavior in possibly-undesirable ways.)  Also,
4697          * we prohibit changing these in a security-restricted operation because
4698          * otherwise RESET could be used to regain the session user's privileges.
4699          */
4700         if (record->flags & GUC_NOT_WHILE_SEC_REST)
4701         {
4702                 if (InLocalUserIdChange())
4703                 {
4704                         /*
4705                          * Phrasing of this error message is historical, but it's the
4706                          * most common case.
4707                          */
4708                         ereport(elevel,
4709                                         (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
4710                                          errmsg("cannot set parameter \"%s\" within security-definer function",
4711                                                         name)));
4712                         return false;
4713                 }
4714                 if (InSecurityRestrictedOperation())
4715                 {
4716                         ereport(elevel,
4717                                         (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
4718                                          errmsg("cannot set parameter \"%s\" within security-restricted operation",
4719                                                         name)));
4720                         return false;
4721                 }
4722         }
4723
4724         /*
4725          * Should we set reset/stacked values?  (If so, the behavior is not
4726          * transactional.)      This is done either when we get a default value from
4727          * the database's/user's/client's default settings or when we reset a
4728          * value to its default.
4729          */
4730         makeDefault = changeVal && (source <= PGC_S_OVERRIDE) &&
4731                 ((value != NULL) || source == PGC_S_DEFAULT);
4732
4733         /*
4734          * Ignore attempted set if overridden by previously processed setting.
4735          * However, if changeVal is false then plow ahead anyway since we are
4736          * trying to find out if the value is potentially good, not actually use
4737          * it. Also keep going if makeDefault is true, since we may want to set
4738          * the reset/stacked values even if we can't set the variable itself.
4739          */
4740         if (record->source > source)
4741         {
4742                 if (changeVal && !makeDefault)
4743                 {
4744                         elog(DEBUG3, "\"%s\": setting ignored because previous source is higher priority",
4745                                  name);
4746                         return true;
4747                 }
4748                 changeVal = false;
4749         }
4750
4751         /*
4752          * Evaluate value and set variable.
4753          */
4754         switch (record->vartype)
4755         {
4756                 case PGC_BOOL:
4757                         {
4758                                 struct config_bool *conf = (struct config_bool *) record;
4759                                 bool            newval;
4760
4761                                 if (value)
4762                                 {
4763                                         if (!parse_bool(value, &newval))
4764                                         {
4765                                                 ereport(elevel,
4766                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4767                                                   errmsg("parameter \"%s\" requires a Boolean value",
4768                                                                  name)));
4769                                                 return false;
4770                                         }
4771                                 }
4772                                 else if (source == PGC_S_DEFAULT)
4773                                         newval = conf->boot_val;
4774                                 else
4775                                 {
4776                                         newval = conf->reset_val;
4777                                         source = conf->gen.reset_source;
4778                                 }
4779
4780                                 /* Save old value to support transaction abort */
4781                                 if (changeVal && !makeDefault)
4782                                         push_old_value(&conf->gen, action);
4783
4784                                 if (conf->assign_hook)
4785                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4786                                         {
4787                                                 ereport(elevel,
4788                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4789                                                          errmsg("invalid value for parameter \"%s\": %d",
4790                                                                         name, (int) newval)));
4791                                                 return false;
4792                                         }
4793
4794                                 if (changeVal)
4795                                 {
4796                                         *conf->variable = newval;
4797                                         conf->gen.source = source;
4798                                 }
4799                                 if (makeDefault)
4800                                 {
4801                                         GucStack   *stack;
4802
4803                                         if (conf->gen.reset_source <= source)
4804                                         {
4805                                                 conf->reset_val = newval;
4806                                                 conf->gen.reset_source = source;
4807                                         }
4808                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4809                                         {
4810                                                 if (stack->source <= source)
4811                                                 {
4812                                                         stack->prior.boolval = newval;
4813                                                         stack->source = source;
4814                                                 }
4815                                         }
4816                                 }
4817                                 break;
4818                         }
4819
4820                 case PGC_INT:
4821                         {
4822                                 struct config_int *conf = (struct config_int *) record;
4823                                 int                     newval;
4824
4825                                 if (value)
4826                                 {
4827                                         const char *hintmsg;
4828
4829                                         if (!parse_int(value, &newval, conf->gen.flags, &hintmsg))
4830                                         {
4831                                                 ereport(elevel,
4832                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4833                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
4834                                                                 name, value),
4835                                                                  hintmsg ? errhint("%s", _(hintmsg)) : 0));
4836                                                 return false;
4837                                         }
4838                                         if (newval < conf->min || newval > conf->max)
4839                                         {
4840                                                 ereport(elevel,
4841                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4842                                                                  errmsg("%d is outside the valid range for parameter \"%s\" (%d .. %d)",
4843                                                                                 newval, name, conf->min, conf->max)));
4844                                                 return false;
4845                                         }
4846                                 }
4847                                 else if (source == PGC_S_DEFAULT)
4848                                         newval = conf->boot_val;
4849                                 else
4850                                 {
4851                                         newval = conf->reset_val;
4852                                         source = conf->gen.reset_source;
4853                                 }
4854
4855                                 /* Save old value to support transaction abort */
4856                                 if (changeVal && !makeDefault)
4857                                         push_old_value(&conf->gen, action);
4858
4859                                 if (conf->assign_hook)
4860                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4861                                         {
4862                                                 ereport(elevel,
4863                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4864                                                          errmsg("invalid value for parameter \"%s\": %d",
4865                                                                         name, newval)));
4866                                                 return false;
4867                                         }
4868
4869                                 if (changeVal)
4870                                 {
4871                                         *conf->variable = newval;
4872                                         conf->gen.source = source;
4873                                 }
4874                                 if (makeDefault)
4875                                 {
4876                                         GucStack   *stack;
4877
4878                                         if (conf->gen.reset_source <= source)
4879                                         {
4880                                                 conf->reset_val = newval;
4881                                                 conf->gen.reset_source = source;
4882                                         }
4883                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4884                                         {
4885                                                 if (stack->source <= source)
4886                                                 {
4887                                                         stack->prior.intval = newval;
4888                                                         stack->source = source;
4889                                                 }
4890                                         }
4891                                 }
4892                                 break;
4893                         }
4894
4895                 case PGC_REAL:
4896                         {
4897                                 struct config_real *conf = (struct config_real *) record;
4898                                 double          newval;
4899
4900                                 if (value)
4901                                 {
4902                                         if (!parse_real(value, &newval))
4903                                         {
4904                                                 ereport(elevel,
4905                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4906                                                   errmsg("parameter \"%s\" requires a numeric value",
4907                                                                  name)));
4908                                                 return false;
4909                                         }
4910                                         if (newval < conf->min || newval > conf->max)
4911                                         {
4912                                                 ereport(elevel,
4913                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4914                                                                  errmsg("%g is outside the valid range for parameter \"%s\" (%g .. %g)",
4915                                                                                 newval, name, conf->min, conf->max)));
4916                                                 return false;
4917                                         }
4918                                 }
4919                                 else if (source == PGC_S_DEFAULT)
4920                                         newval = conf->boot_val;
4921                                 else
4922                                 {
4923                                         newval = conf->reset_val;
4924                                         source = conf->gen.reset_source;
4925                                 }
4926
4927                                 /* Save old value to support transaction abort */
4928                                 if (changeVal && !makeDefault)
4929                                         push_old_value(&conf->gen, action);
4930
4931                                 if (conf->assign_hook)
4932                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4933                                         {
4934                                                 ereport(elevel,
4935                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4936                                                          errmsg("invalid value for parameter \"%s\": %g",
4937                                                                         name, newval)));
4938                                                 return false;
4939                                         }
4940
4941                                 if (changeVal)
4942                                 {
4943                                         *conf->variable = newval;
4944                                         conf->gen.source = source;
4945                                 }
4946                                 if (makeDefault)
4947                                 {
4948                                         GucStack   *stack;
4949
4950                                         if (conf->gen.reset_source <= source)
4951                                         {
4952                                                 conf->reset_val = newval;
4953                                                 conf->gen.reset_source = source;
4954                                         }
4955                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4956                                         {
4957                                                 if (stack->source <= source)
4958                                                 {
4959                                                         stack->prior.realval = newval;
4960                                                         stack->source = source;
4961                                                 }
4962                                         }
4963                                 }
4964                                 break;
4965                         }
4966
4967                 case PGC_STRING:
4968                         {
4969                                 struct config_string *conf = (struct config_string *) record;
4970                                 char       *newval;
4971
4972                                 if (value)
4973                                 {
4974                                         newval = guc_strdup(elevel, value);
4975                                         if (newval == NULL)
4976                                                 return false;
4977
4978                                         /*
4979                                          * The only sort of "parsing" check we need to do is apply
4980                                          * truncation if GUC_IS_NAME.
4981                                          */
4982                                         if (conf->gen.flags & GUC_IS_NAME)
4983                                                 truncate_identifier(newval, strlen(newval), true);
4984                                 }
4985                                 else if (source == PGC_S_DEFAULT)
4986                                 {
4987                                         if (conf->boot_val == NULL)
4988                                                 newval = NULL;
4989                                         else
4990                                         {
4991                                                 newval = guc_strdup(elevel, conf->boot_val);
4992                                                 if (newval == NULL)
4993                                                         return false;
4994                                         }
4995                                 }
4996                                 else
4997                                 {
4998                                         /*
4999                                          * We could possibly avoid strdup here, but easier to make
5000                                          * this case work the same as the normal assignment case;
5001                                          * note the possible free of newval below.
5002                                          */
5003                                         if (conf->reset_val == NULL)
5004                                                 newval = NULL;
5005                                         else
5006                                         {
5007                                                 newval = guc_strdup(elevel, conf->reset_val);
5008                                                 if (newval == NULL)
5009                                                         return false;
5010                                         }
5011                                         source = conf->gen.reset_source;
5012                                 }
5013
5014                                 /* Save old value to support transaction abort */
5015                                 if (changeVal && !makeDefault)
5016                                         push_old_value(&conf->gen, action);
5017
5018                                 if (conf->assign_hook && newval)
5019                                 {
5020                                         const char *hookresult;
5021
5022                                         /*
5023                                          * If the hook ereports, we have to make sure we free
5024                                          * newval, else it will be a permanent memory leak.
5025                                          */
5026                                         hookresult = call_string_assign_hook(conf->assign_hook,
5027                                                                                                                  newval,
5028                                                                                                                  changeVal,
5029                                                                                                                  source);
5030                                         if (hookresult == NULL)
5031                                         {
5032                                                 free(newval);
5033                                                 ereport(elevel,
5034                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5035                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
5036                                                                 name, value ? value : "")));
5037                                                 return false;
5038                                         }
5039                                         else if (hookresult != newval)
5040                                         {
5041                                                 free(newval);
5042
5043                                                 /*
5044                                                  * Having to cast away const here is annoying, but the
5045                                                  * alternative is to declare assign_hooks as returning
5046                                                  * char*, which would mean they'd have to cast away
5047                                                  * const, or as both taking and returning char*, which
5048                                                  * doesn't seem attractive either --- we don't want
5049                                                  * them to scribble on the passed str.
5050                                                  */
5051                                                 newval = (char *) hookresult;
5052                                         }
5053                                 }
5054
5055                                 if (changeVal)
5056                                 {
5057                                         set_string_field(conf, conf->variable, newval);
5058                                         conf->gen.source = source;
5059                                 }
5060                                 if (makeDefault)
5061                                 {
5062                                         GucStack   *stack;
5063
5064                                         if (conf->gen.reset_source <= source)
5065                                         {
5066                                                 set_string_field(conf, &conf->reset_val, newval);
5067                                                 conf->gen.reset_source = source;
5068                                         }
5069                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
5070                                         {
5071                                                 if (stack->source <= source)
5072                                                 {
5073                                                         set_string_field(conf, &stack->prior.stringval,
5074                                                                                          newval);
5075                                                         stack->source = source;
5076                                                 }
5077                                         }
5078                                 }
5079                                 /* Perhaps we didn't install newval anywhere */
5080                                 if (newval && !string_field_used(conf, newval))
5081                                         free(newval);
5082                                 break;
5083                         }
5084                 case PGC_ENUM:
5085                         {
5086                                 struct config_enum *conf = (struct config_enum *) record;
5087                                 int                     newval;
5088
5089                                 if (value)
5090                                 {
5091                                         if (!config_enum_lookup_by_name(conf, value, &newval))
5092                                         {
5093                                                 char       *hintmsg;
5094
5095                                                 hintmsg = config_enum_get_options(conf,
5096                                                                                                                 "Available values: ",
5097                                                                                                                   ".", ", ");
5098
5099                                                 ereport(elevel,
5100                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5101                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
5102                                                                 name, value),
5103                                                                  hintmsg ? errhint("%s", _(hintmsg)) : 0));
5104
5105                                                 if (hintmsg)
5106                                                         pfree(hintmsg);
5107                                                 return false;
5108                                         }
5109                                 }
5110                                 else if (source == PGC_S_DEFAULT)
5111                                         newval = conf->boot_val;
5112                                 else
5113                                 {
5114                                         newval = conf->reset_val;
5115                                         source = conf->gen.reset_source;
5116                                 }
5117
5118                                 /* Save old value to support transaction abort */
5119                                 if (changeVal && !makeDefault)
5120                                         push_old_value(&conf->gen, action);
5121
5122                                 if (conf->assign_hook)
5123                                         if (!(*conf->assign_hook) (newval, changeVal, source))
5124                                         {
5125                                                 ereport(elevel,
5126                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5127                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
5128                                                                 name,
5129                                                                 config_enum_lookup_by_value(conf, newval))));
5130                                                 return false;
5131                                         }
5132
5133                                 if (changeVal)
5134                                 {
5135                                         *conf->variable = newval;
5136                                         conf->gen.source = source;
5137                                 }
5138                                 if (makeDefault)
5139                                 {
5140                                         GucStack   *stack;
5141
5142                                         if (conf->gen.reset_source <= source)
5143                                         {
5144                                                 conf->reset_val = newval;
5145                                                 conf->gen.reset_source = source;
5146                                         }
5147                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
5148                                         {
5149                                                 if (stack->source <= source)
5150                                                 {
5151                                                         stack->prior.enumval = newval;
5152                                                         stack->source = source;
5153                                                 }
5154                                         }
5155                                 }
5156                                 break;
5157                         }
5158         }
5159
5160         if (changeVal && (record->flags & GUC_REPORT))
5161                 ReportGUCOption(record);
5162
5163         return true;
5164 }
5165
5166
5167 /*
5168  * Set the fields for source file and line number the setting came from.
5169  */
5170 static void
5171 set_config_sourcefile(const char *name, char *sourcefile, int sourceline)
5172 {
5173         struct config_generic *record;
5174         int                     elevel;
5175
5176         /*
5177          * To avoid cluttering the log, only the postmaster bleats loudly about
5178          * problems with the config file.
5179          */
5180         elevel = IsUnderPostmaster ? DEBUG3 : LOG;
5181
5182         record = find_option(name, true, elevel);
5183         /* should not happen */
5184         if (record == NULL)
5185                 elog(ERROR, "unrecognized configuration parameter \"%s\"", name);
5186
5187         sourcefile = guc_strdup(elevel, sourcefile);
5188         if (record->sourcefile)
5189                 free(record->sourcefile);
5190         record->sourcefile = sourcefile;
5191         record->sourceline = sourceline;
5192 }
5193
5194 /*
5195  * Set a config option to the given value. See also set_config_option,
5196  * this is just the wrapper to be called from outside GUC.      NB: this
5197  * is used only for non-transactional operations.
5198  *
5199  * Note: there is no support here for setting source file/line, as it
5200  * is currently not needed.
5201  */
5202 void
5203 SetConfigOption(const char *name, const char *value,
5204                                 GucContext context, GucSource source)
5205 {
5206         (void) set_config_option(name, value, context, source,
5207                                                          GUC_ACTION_SET, true);
5208 }
5209
5210
5211
5212 /*
5213  * Fetch the current value of the option `name'. If the option doesn't exist,
5214  * throw an ereport and don't return.
5215  *
5216  * If restrict_superuser is true, we also enforce that only superusers can
5217  * see GUC_SUPERUSER_ONLY variables.  This should only be passed as true
5218  * in user-driven calls.
5219  *
5220  * The string is *not* allocated for modification and is really only
5221  * valid until the next call to configuration related functions.
5222  */
5223 const char *
5224 GetConfigOption(const char *name, bool restrict_superuser)
5225 {
5226         struct config_generic *record;
5227         static char buffer[256];
5228
5229         record = find_option(name, false, ERROR);
5230         if (record == NULL)
5231                 ereport(ERROR,
5232                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5233                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5234         if (restrict_superuser &&
5235                 (record->flags & GUC_SUPERUSER_ONLY) &&
5236                 !superuser())
5237                 ereport(ERROR,
5238                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5239                                  errmsg("must be superuser to examine \"%s\"", name)));
5240
5241         switch (record->vartype)
5242         {
5243                 case PGC_BOOL:
5244                         return *((struct config_bool *) record)->variable ? "on" : "off";
5245
5246                 case PGC_INT:
5247                         snprintf(buffer, sizeof(buffer), "%d",
5248                                          *((struct config_int *) record)->variable);
5249                         return buffer;
5250
5251                 case PGC_REAL:
5252                         snprintf(buffer, sizeof(buffer), "%g",
5253                                          *((struct config_real *) record)->variable);
5254                         return buffer;
5255
5256                 case PGC_STRING:
5257                         return *((struct config_string *) record)->variable;
5258
5259                 case PGC_ENUM:
5260                         return config_enum_lookup_by_value((struct config_enum *) record,
5261                                                                  *((struct config_enum *) record)->variable);
5262         }
5263         return NULL;
5264 }
5265
5266 /*
5267  * Get the RESET value associated with the given option.
5268  *
5269  * Note: this is not re-entrant, due to use of static result buffer;
5270  * not to mention that a string variable could have its reset_val changed.
5271  * Beware of assuming the result value is good for very long.
5272  */
5273 const char *
5274 GetConfigOptionResetString(const char *name)
5275 {
5276         struct config_generic *record;
5277         static char buffer[256];
5278
5279         record = find_option(name, false, ERROR);
5280         if (record == NULL)
5281                 ereport(ERROR,
5282                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5283                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5284         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
5285                 ereport(ERROR,
5286                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5287                                  errmsg("must be superuser to examine \"%s\"", name)));
5288
5289         switch (record->vartype)
5290         {
5291                 case PGC_BOOL:
5292                         return ((struct config_bool *) record)->reset_val ? "on" : "off";
5293
5294                 case PGC_INT:
5295                         snprintf(buffer, sizeof(buffer), "%d",
5296                                          ((struct config_int *) record)->reset_val);
5297                         return buffer;
5298
5299                 case PGC_REAL:
5300                         snprintf(buffer, sizeof(buffer), "%g",
5301                                          ((struct config_real *) record)->reset_val);
5302                         return buffer;
5303
5304                 case PGC_STRING:
5305                         return ((struct config_string *) record)->reset_val;
5306
5307                 case PGC_ENUM:
5308                         return config_enum_lookup_by_value((struct config_enum *) record,
5309                                                                  ((struct config_enum *) record)->reset_val);
5310         }
5311         return NULL;
5312 }
5313
5314
5315 /*
5316  * GUC_complaint_elevel
5317  *              Get the ereport error level to use in an assign_hook's error report.
5318  *
5319  * This should be used by assign hooks that want to emit a custom error
5320  * report (in addition to the generic "invalid value for option FOO" that
5321  * guc.c will provide).  Note that the result might be ERROR or a lower
5322  * level, so the caller must be prepared for control to return from ereport,
5323  * or not.      If control does return, return false/NULL from the hook function.
5324  *
5325  * At some point it'd be nice to replace this with a mechanism that allows
5326  * the custom message to become the DETAIL line of guc.c's generic message.
5327  */
5328 int
5329 GUC_complaint_elevel(GucSource source)
5330 {
5331         int                     elevel;
5332
5333         if (source == PGC_S_FILE)
5334         {
5335                 /*
5336                  * To avoid cluttering the log, only the postmaster bleats loudly
5337                  * about problems with the config file.
5338                  */
5339                 elevel = IsUnderPostmaster ? DEBUG3 : LOG;
5340         }
5341         else if (source == PGC_S_OVERRIDE)
5342         {
5343                 /*
5344                  * If we're a postmaster child, this is probably "undo" during
5345                  * transaction abort, so we don't want to clutter the log.  There's a
5346                  * small chance of a real problem with an OVERRIDE setting, though, so
5347                  * suppressing the message entirely wouldn't be desirable.
5348                  */
5349                 elevel = IsUnderPostmaster ? DEBUG5 : LOG;
5350         }
5351         else if (source < PGC_S_INTERACTIVE)
5352                 elevel = LOG;
5353         else
5354                 elevel = ERROR;
5355
5356         return elevel;
5357 }
5358
5359
5360 /*
5361  * flatten_set_variable_args
5362  *              Given a parsenode List as emitted by the grammar for SET,
5363  *              convert to the flat string representation used by GUC.
5364  *
5365  * We need to be told the name of the variable the args are for, because
5366  * the flattening rules vary (ugh).
5367  *
5368  * The result is NULL if args is NIL (ie, SET ... TO DEFAULT), otherwise
5369  * a palloc'd string.
5370  */
5371 static char *
5372 flatten_set_variable_args(const char *name, List *args)
5373 {
5374         struct config_generic *record;
5375         int                     flags;
5376         StringInfoData buf;
5377         ListCell   *l;
5378
5379         /* Fast path if just DEFAULT */
5380         if (args == NIL)
5381                 return NULL;
5382
5383         /* Else get flags for the variable */
5384         record = find_option(name, true, ERROR);
5385         if (record == NULL)
5386                 ereport(ERROR,
5387                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5388                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5389
5390         flags = record->flags;
5391
5392         /* Complain if list input and non-list variable */
5393         if ((flags & GUC_LIST_INPUT) == 0 &&
5394                 list_length(args) != 1)
5395                 ereport(ERROR,
5396                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5397                                  errmsg("SET %s takes only one argument", name)));
5398
5399         initStringInfo(&buf);
5400
5401         /*
5402          * Each list member may be a plain A_Const node, or an A_Const within a
5403          * TypeCast; the latter case is supported only for ConstInterval arguments
5404          * (for SET TIME ZONE).
5405          */
5406         foreach(l, args)
5407         {
5408                 Node       *arg = (Node *) lfirst(l);
5409                 char       *val;
5410                 TypeName   *typeName = NULL;
5411                 A_Const    *con;
5412
5413                 if (l != list_head(args))
5414                         appendStringInfo(&buf, ", ");
5415
5416                 if (IsA(arg, TypeCast))
5417                 {
5418                         TypeCast   *tc = (TypeCast *) arg;
5419
5420                         arg = tc->arg;
5421                         typeName = tc->typeName;
5422                 }
5423
5424                 if (!IsA(arg, A_Const))
5425                         elog(ERROR, "unrecognized node type: %d", (int) nodeTag(arg));
5426                 con = (A_Const *) arg;
5427
5428                 switch (nodeTag(&con->val))
5429                 {
5430                         case T_Integer:
5431                                 appendStringInfo(&buf, "%ld", intVal(&con->val));
5432                                 break;
5433                         case T_Float:
5434                                 /* represented as a string, so just copy it */
5435                                 appendStringInfoString(&buf, strVal(&con->val));
5436                                 break;
5437                         case T_String:
5438                                 val = strVal(&con->val);
5439                                 if (typeName != NULL)
5440                                 {
5441                                         /*
5442                                          * Must be a ConstInterval argument for TIME ZONE. Coerce
5443                                          * to interval and back to normalize the value and account
5444                                          * for any typmod.
5445                                          */
5446                                         Oid                     typoid;
5447                                         int32           typmod;
5448                                         Datum           interval;
5449                                         char       *intervalout;
5450
5451                                         typoid = typenameTypeId(NULL, typeName, &typmod);
5452                                         Assert(typoid == INTERVALOID);
5453
5454                                         interval =
5455                                                 DirectFunctionCall3(interval_in,
5456                                                                                         CStringGetDatum(val),
5457                                                                                         ObjectIdGetDatum(InvalidOid),
5458                                                                                         Int32GetDatum(typmod));
5459
5460                                         intervalout =
5461                                                 DatumGetCString(DirectFunctionCall1(interval_out,
5462                                                                                                                         interval));
5463                                         appendStringInfo(&buf, "INTERVAL '%s'", intervalout);
5464                                 }
5465                                 else
5466                                 {
5467                                         /*
5468                                          * Plain string literal or identifier.  For quote mode,
5469                                          * quote it if it's not a vanilla identifier.
5470                                          */
5471                                         if (flags & GUC_LIST_QUOTE)
5472                                                 appendStringInfoString(&buf, quote_identifier(val));
5473                                         else
5474                                                 appendStringInfoString(&buf, val);
5475                                 }
5476                                 break;
5477                         default:
5478                                 elog(ERROR, "unrecognized node type: %d",
5479                                          (int) nodeTag(&con->val));
5480                                 break;
5481                 }
5482         }
5483
5484         return buf.data;
5485 }
5486
5487
5488 /*
5489  * SET command
5490  */
5491 void
5492 ExecSetVariableStmt(VariableSetStmt *stmt)
5493 {
5494         GucAction       action = stmt->is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET;
5495
5496         switch (stmt->kind)
5497         {
5498                 case VAR_SET_VALUE:
5499                 case VAR_SET_CURRENT:
5500                         set_config_option(stmt->name,
5501                                                           ExtractSetVariableArgs(stmt),
5502                                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5503                                                           PGC_S_SESSION,
5504                                                           action,
5505                                                           true);
5506                         break;
5507                 case VAR_SET_MULTI:
5508
5509                         /*
5510                          * Special case for special SQL syntax that effectively sets more
5511                          * than one variable per statement.
5512                          */
5513                         if (strcmp(stmt->name, "TRANSACTION") == 0)
5514                         {
5515                                 ListCell   *head;
5516
5517                                 foreach(head, stmt->args)
5518                                 {
5519                                         DefElem    *item = (DefElem *) lfirst(head);
5520
5521                                         if (strcmp(item->defname, "transaction_isolation") == 0)
5522                                                 SetPGVariable("transaction_isolation",
5523                                                                           list_make1(item->arg), stmt->is_local);
5524                                         else if (strcmp(item->defname, "transaction_read_only") == 0)
5525                                                 SetPGVariable("transaction_read_only",
5526                                                                           list_make1(item->arg), stmt->is_local);
5527                                         else
5528                                                 elog(ERROR, "unexpected SET TRANSACTION element: %s",
5529                                                          item->defname);
5530                                 }
5531                         }
5532                         else if (strcmp(stmt->name, "SESSION CHARACTERISTICS") == 0)
5533                         {
5534                                 ListCell   *head;
5535
5536                                 foreach(head, stmt->args)
5537                                 {
5538                                         DefElem    *item = (DefElem *) lfirst(head);
5539
5540                                         if (strcmp(item->defname, "transaction_isolation") == 0)
5541                                                 SetPGVariable("default_transaction_isolation",
5542                                                                           list_make1(item->arg), stmt->is_local);
5543                                         else if (strcmp(item->defname, "transaction_read_only") == 0)
5544                                                 SetPGVariable("default_transaction_read_only",
5545                                                                           list_make1(item->arg), stmt->is_local);
5546                                         else
5547                                                 elog(ERROR, "unexpected SET SESSION element: %s",
5548                                                          item->defname);
5549                                 }
5550                         }
5551                         else
5552                                 elog(ERROR, "unexpected SET MULTI element: %s",
5553                                          stmt->name);
5554                         break;
5555                 case VAR_SET_DEFAULT:
5556                 case VAR_RESET:
5557                         set_config_option(stmt->name,
5558                                                           NULL,
5559                                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5560                                                           PGC_S_SESSION,
5561                                                           action,
5562                                                           true);
5563                         break;
5564                 case VAR_RESET_ALL:
5565                         ResetAllOptions();
5566                         break;
5567         }
5568 }
5569
5570 /*
5571  * Get the value to assign for a VariableSetStmt, or NULL if it's RESET.
5572  * The result is palloc'd.
5573  *
5574  * This is exported for use by actions such as ALTER ROLE SET.
5575  */
5576 char *
5577 ExtractSetVariableArgs(VariableSetStmt *stmt)
5578 {
5579         switch (stmt->kind)
5580         {
5581                 case VAR_SET_VALUE:
5582                         return flatten_set_variable_args(stmt->name, stmt->args);
5583                 case VAR_SET_CURRENT:
5584                         return GetConfigOptionByName(stmt->name, NULL);
5585                 default:
5586                         return NULL;
5587         }
5588 }
5589
5590 /*
5591  * SetPGVariable - SET command exported as an easily-C-callable function.
5592  *
5593  * This provides access to SET TO value, as well as SET TO DEFAULT (expressed
5594  * by passing args == NIL), but not SET FROM CURRENT functionality.
5595  */
5596 void
5597 SetPGVariable(const char *name, List *args, bool is_local)
5598 {
5599         char       *argstring = flatten_set_variable_args(name, args);
5600
5601         /* Note SET DEFAULT (argstring == NULL) is equivalent to RESET */
5602         set_config_option(name,
5603                                           argstring,
5604                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5605                                           PGC_S_SESSION,
5606                                           is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET,
5607                                           true);
5608 }
5609
5610 /*
5611  * SET command wrapped as a SQL callable function.
5612  */
5613 Datum
5614 set_config_by_name(PG_FUNCTION_ARGS)
5615 {
5616         char       *name;
5617         char       *value;
5618         char       *new_value;
5619         bool            is_local;
5620
5621         if (PG_ARGISNULL(0))
5622                 ereport(ERROR,
5623                                 (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
5624                                  errmsg("SET requires parameter name")));
5625
5626         /* Get the GUC variable name */
5627         name = TextDatumGetCString(PG_GETARG_DATUM(0));
5628
5629         /* Get the desired value or set to NULL for a reset request */
5630         if (PG_ARGISNULL(1))
5631                 value = NULL;
5632         else
5633                 value = TextDatumGetCString(PG_GETARG_DATUM(1));
5634
5635         /*
5636          * Get the desired state of is_local. Default to false if provided value
5637          * is NULL
5638          */
5639         if (PG_ARGISNULL(2))
5640                 is_local = false;
5641         else
5642                 is_local = PG_GETARG_BOOL(2);
5643
5644         /* Note SET DEFAULT (argstring == NULL) is equivalent to RESET */
5645         set_config_option(name,
5646                                           value,
5647                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5648                                           PGC_S_SESSION,
5649                                           is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET,
5650                                           true);
5651
5652         /* get the new current value */
5653         new_value = GetConfigOptionByName(name, NULL);
5654
5655         /* Convert return string to text */
5656         PG_RETURN_TEXT_P(cstring_to_text(new_value));
5657 }
5658
5659
5660 /*
5661  * Common code for DefineCustomXXXVariable subroutines: allocate the
5662  * new variable's config struct and fill in generic fields.
5663  */
5664 static struct config_generic *
5665 init_custom_variable(const char *name,
5666                                          const char *short_desc,
5667                                          const char *long_desc,
5668                                          GucContext context,
5669                                          int flags,
5670                                          enum config_type type,
5671                                          size_t sz)
5672 {
5673         struct config_generic *gen;
5674
5675         /*
5676          * Only allow custom PGC_POSTMASTER variables to be created during shared
5677          * library preload; any later than that, we can't ensure that the value
5678          * doesn't change after startup.  This is a fatal elog if it happens; just
5679          * erroring out isn't safe because we don't know what the calling loadable
5680          * module might already have hooked into.
5681          */
5682         if (context == PGC_POSTMASTER &&
5683                 !process_shared_preload_libraries_in_progress)
5684                 elog(FATAL, "cannot create PGC_POSTMASTER variables after startup");
5685
5686         gen = (struct config_generic *) guc_malloc(ERROR, sz);
5687         memset(gen, 0, sz);
5688
5689         gen->name = guc_strdup(ERROR, name);
5690         gen->context = context;
5691         gen->group = CUSTOM_OPTIONS;
5692         gen->short_desc = short_desc;
5693         gen->long_desc = long_desc;
5694         gen->flags = flags;
5695         gen->vartype = type;
5696
5697         return gen;
5698 }
5699
5700 /*
5701  * Common code for DefineCustomXXXVariable subroutines: insert the new
5702  * variable into the GUC variable array, replacing any placeholder.
5703  */
5704 static void
5705 define_custom_variable(struct config_generic * variable)
5706 {
5707         const char *name = variable->name;
5708         const char **nameAddr = &name;
5709         const char *value;
5710         struct config_string *pHolder;
5711         GucContext      phcontext;
5712         struct config_generic **res;
5713
5714         /*
5715          * See if there's a placeholder by the same name.
5716          */
5717         res = (struct config_generic **) bsearch((void *) &nameAddr,
5718                                                                                          (void *) guc_variables,
5719                                                                                          num_guc_variables,
5720                                                                                          sizeof(struct config_generic *),
5721                                                                                          guc_var_compare);
5722         if (res == NULL)
5723         {
5724                 /*
5725                  * No placeholder to replace, so we can just add it ... but first,
5726                  * make sure it's initialized to its default value.
5727                  */
5728                 InitializeOneGUCOption(variable);
5729                 add_guc_variable(variable, ERROR);
5730                 return;
5731         }
5732
5733         /*
5734          * This better be a placeholder
5735          */
5736         if (((*res)->flags & GUC_CUSTOM_PLACEHOLDER) == 0)
5737                 ereport(ERROR,
5738                                 (errcode(ERRCODE_INTERNAL_ERROR),
5739                                  errmsg("attempt to redefine parameter \"%s\"", name)));
5740
5741         Assert((*res)->vartype == PGC_STRING);
5742         pHolder = (struct config_string *) (*res);
5743
5744         /*
5745          * First, set the variable to its default value.  We must do this even
5746          * though we intend to immediately apply a new value, since it's possible
5747          * that the new value is invalid.
5748          */
5749         InitializeOneGUCOption(variable);
5750
5751         /*
5752          * Replace the placeholder. We aren't changing the name, so no re-sorting
5753          * is necessary
5754          */
5755         *res = variable;
5756
5757         /*
5758          * Infer context for assignment based on source of existing value. We
5759          * can't tell this with exact accuracy, but we can at least do something
5760          * reasonable in typical cases.
5761          */
5762         switch (pHolder->gen.source)
5763         {
5764                 case PGC_S_DEFAULT:
5765                 case PGC_S_ENV_VAR:
5766                 case PGC_S_FILE:
5767                 case PGC_S_ARGV:
5768
5769                         /*
5770                          * If we got past the check in init_custom_variable, we can safely
5771                          * assume that any existing value for a PGC_POSTMASTER variable
5772                          * was set in postmaster context.
5773                          */
5774                         if (variable->context == PGC_POSTMASTER)
5775                                 phcontext = PGC_POSTMASTER;
5776                         else
5777                                 phcontext = PGC_SIGHUP;
5778                         break;
5779                 case PGC_S_DATABASE:
5780                 case PGC_S_USER:
5781                 case PGC_S_DATABASE_USER:
5782                 case PGC_S_CLIENT:
5783                 case PGC_S_SESSION:
5784                 default:
5785                         phcontext = PGC_USERSET;
5786                         break;
5787         }
5788
5789         /*
5790          * Assign the string value stored in the placeholder to the real variable.
5791          *
5792          * XXX this is not really good enough --- it should be a nontransactional
5793          * assignment, since we don't want it to roll back if the current xact
5794          * fails later.  (Or do we?)
5795          */
5796         value = *pHolder->variable;
5797
5798         if (value)
5799         {
5800                 if (set_config_option(name, value,
5801                                                           phcontext, pHolder->gen.source,
5802                                                           GUC_ACTION_SET, true))
5803                 {
5804                         /* Also copy over any saved source-location information */
5805                         if (pHolder->gen.sourcefile)
5806                                 set_config_sourcefile(name, pHolder->gen.sourcefile,
5807                                                                           pHolder->gen.sourceline);
5808                 }
5809         }
5810
5811         /*
5812          * Free up as much as we conveniently can of the placeholder structure
5813          * (this neglects any stack items...)
5814          */
5815         set_string_field(pHolder, pHolder->variable, NULL);
5816         set_string_field(pHolder, &pHolder->reset_val, NULL);
5817
5818         free(pHolder);
5819 }
5820
5821 void
5822 DefineCustomBoolVariable(const char *name,
5823                                                  const char *short_desc,
5824                                                  const char *long_desc,
5825                                                  bool *valueAddr,
5826                                                  bool bootValue,
5827                                                  GucContext context,
5828                                                  int flags,
5829                                                  GucBoolAssignHook assign_hook,
5830                                                  GucShowHook show_hook)
5831 {
5832         struct config_bool *var;
5833
5834         var = (struct config_bool *)
5835                 init_custom_variable(name, short_desc, long_desc, context, flags,
5836                                                          PGC_BOOL, sizeof(struct config_bool));
5837         var->variable = valueAddr;
5838         var->boot_val = bootValue;
5839         var->reset_val = bootValue;
5840         var->assign_hook = assign_hook;
5841         var->show_hook = show_hook;
5842         define_custom_variable(&var->gen);
5843 }
5844
5845 void
5846 DefineCustomIntVariable(const char *name,
5847                                                 const char *short_desc,
5848                                                 const char *long_desc,
5849                                                 int *valueAddr,
5850                                                 int bootValue,
5851                                                 int minValue,
5852                                                 int maxValue,
5853                                                 GucContext context,
5854                                                 int flags,
5855                                                 GucIntAssignHook assign_hook,
5856                                                 GucShowHook show_hook)
5857 {
5858         struct config_int *var;
5859
5860         var = (struct config_int *)
5861                 init_custom_variable(name, short_desc, long_desc, context, flags,
5862                                                          PGC_INT, sizeof(struct config_int));
5863         var->variable = valueAddr;
5864         var->boot_val = bootValue;
5865         var->reset_val = bootValue;
5866         var->min = minValue;
5867         var->max = maxValue;
5868         var->assign_hook = assign_hook;
5869         var->show_hook = show_hook;
5870         define_custom_variable(&var->gen);
5871 }
5872
5873 void
5874 DefineCustomRealVariable(const char *name,
5875                                                  const char *short_desc,
5876                                                  const char *long_desc,
5877                                                  double *valueAddr,
5878                                                  double bootValue,
5879                                                  double minValue,
5880                                                  double maxValue,
5881                                                  GucContext context,
5882                                                  int flags,
5883                                                  GucRealAssignHook assign_hook,
5884                                                  GucShowHook show_hook)
5885 {
5886         struct config_real *var;
5887
5888         var = (struct config_real *)
5889                 init_custom_variable(name, short_desc, long_desc, context, flags,
5890                                                          PGC_REAL, sizeof(struct config_real));
5891         var->variable = valueAddr;
5892         var->boot_val = bootValue;
5893         var->reset_val = bootValue;
5894         var->min = minValue;
5895         var->max = maxValue;
5896         var->assign_hook = assign_hook;
5897         var->show_hook = show_hook;
5898         define_custom_variable(&var->gen);
5899 }
5900
5901 void
5902 DefineCustomStringVariable(const char *name,
5903                                                    const char *short_desc,
5904                                                    const char *long_desc,
5905                                                    char **valueAddr,
5906                                                    const char *bootValue,
5907                                                    GucContext context,
5908                                                    int flags,
5909                                                    GucStringAssignHook assign_hook,
5910                                                    GucShowHook show_hook)
5911 {
5912         struct config_string *var;
5913
5914         var = (struct config_string *)
5915                 init_custom_variable(name, short_desc, long_desc, context, flags,
5916                                                          PGC_STRING, sizeof(struct config_string));
5917         var->variable = valueAddr;
5918         var->boot_val = bootValue;
5919         /* we could probably do without strdup, but keep it like normal case */
5920         if (var->boot_val)
5921                 var->reset_val = guc_strdup(ERROR, var->boot_val);
5922         var->assign_hook = assign_hook;
5923         var->show_hook = show_hook;
5924         define_custom_variable(&var->gen);
5925 }
5926
5927 void
5928 DefineCustomEnumVariable(const char *name,
5929                                                  const char *short_desc,
5930                                                  const char *long_desc,
5931                                                  int *valueAddr,
5932                                                  int bootValue,
5933                                                  const struct config_enum_entry * options,
5934                                                  GucContext context,
5935                                                  int flags,
5936                                                  GucEnumAssignHook assign_hook,
5937                                                  GucShowHook show_hook)
5938 {
5939         struct config_enum *var;
5940
5941         var = (struct config_enum *)
5942                 init_custom_variable(name, short_desc, long_desc, context, flags,
5943                                                          PGC_ENUM, sizeof(struct config_enum));
5944         var->variable = valueAddr;
5945         var->boot_val = bootValue;
5946         var->reset_val = bootValue;
5947         var->options = options;
5948         var->assign_hook = assign_hook;
5949         var->show_hook = show_hook;
5950         define_custom_variable(&var->gen);
5951 }
5952
5953 void
5954 EmitWarningsOnPlaceholders(const char *className)
5955 {
5956         int                     classLen = strlen(className);
5957         int                     i;
5958
5959         for (i = 0; i < num_guc_variables; i++)
5960         {
5961                 struct config_generic *var = guc_variables[i];
5962
5963                 if ((var->flags & GUC_CUSTOM_PLACEHOLDER) != 0 &&
5964                         strncmp(className, var->name, classLen) == 0 &&
5965                         var->name[classLen] == GUC_QUALIFIER_SEPARATOR)
5966                 {
5967                         ereport(WARNING,
5968                                         (errcode(ERRCODE_UNDEFINED_OBJECT),
5969                                          errmsg("unrecognized configuration parameter \"%s\"",
5970                                                         var->name)));
5971                 }
5972         }
5973 }
5974
5975
5976 /*
5977  * SHOW command
5978  */
5979 void
5980 GetPGVariable(const char *name, DestReceiver *dest)
5981 {
5982         if (guc_name_compare(name, "all") == 0)
5983                 ShowAllGUCConfig(dest);
5984         else
5985                 ShowGUCConfigOption(name, dest);
5986 }
5987
5988 TupleDesc
5989 GetPGVariableResultDesc(const char *name)
5990 {
5991         TupleDesc       tupdesc;
5992
5993         if (guc_name_compare(name, "all") == 0)
5994         {
5995                 /* need a tuple descriptor representing three TEXT columns */
5996                 tupdesc = CreateTemplateTupleDesc(3, false);
5997                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
5998                                                    TEXTOID, -1, 0);
5999                 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
6000                                                    TEXTOID, -1, 0);
6001                 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "description",
6002                                                    TEXTOID, -1, 0);
6003         }
6004         else
6005         {
6006                 const char *varname;
6007
6008                 /* Get the canonical spelling of name */
6009                 (void) GetConfigOptionByName(name, &varname);
6010
6011                 /* need a tuple descriptor representing a single TEXT column */
6012                 tupdesc = CreateTemplateTupleDesc(1, false);
6013                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, varname,
6014                                                    TEXTOID, -1, 0);
6015         }
6016         return tupdesc;
6017 }
6018
6019
6020 /*
6021  * SHOW command
6022  */
6023 static void
6024 ShowGUCConfigOption(const char *name, DestReceiver *dest)
6025 {
6026         TupOutputState *tstate;
6027         TupleDesc       tupdesc;
6028         const char *varname;
6029         char       *value;
6030
6031         /* Get the value and canonical spelling of name */
6032         value = GetConfigOptionByName(name, &varname);
6033
6034         /* need a tuple descriptor representing a single TEXT column */
6035         tupdesc = CreateTemplateTupleDesc(1, false);
6036         TupleDescInitEntry(tupdesc, (AttrNumber) 1, varname,
6037                                            TEXTOID, -1, 0);
6038
6039         /* prepare for projection of tuples */
6040         tstate = begin_tup_output_tupdesc(dest, tupdesc);
6041
6042         /* Send it */
6043         do_text_output_oneline(tstate, value);
6044
6045         end_tup_output(tstate);
6046 }
6047
6048 /*
6049  * SHOW ALL command
6050  */
6051 static void
6052 ShowAllGUCConfig(DestReceiver *dest)
6053 {
6054         bool            am_superuser = superuser();
6055         int                     i;
6056         TupOutputState *tstate;
6057         TupleDesc       tupdesc;
6058         Datum       values[3];
6059         bool            isnull[3] = { false, false, false };
6060
6061         /* need a tuple descriptor representing three TEXT columns */
6062         tupdesc = CreateTemplateTupleDesc(3, false);
6063         TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
6064                                            TEXTOID, -1, 0);
6065         TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
6066                                            TEXTOID, -1, 0);
6067         TupleDescInitEntry(tupdesc, (AttrNumber) 3, "description",
6068                                            TEXTOID, -1, 0);
6069
6070         /* prepare for projection of tuples */
6071         tstate = begin_tup_output_tupdesc(dest, tupdesc);
6072
6073         for (i = 0; i < num_guc_variables; i++)
6074         {
6075                 struct config_generic *conf = guc_variables[i];
6076                 char   *setting;
6077
6078                 if ((conf->flags & GUC_NO_SHOW_ALL) ||
6079                         ((conf->flags & GUC_SUPERUSER_ONLY) && !am_superuser))
6080                         continue;
6081
6082                 /* assign to the values array */
6083                 values[0] = PointerGetDatum(cstring_to_text(conf->name));
6084
6085                 setting = _ShowOption(conf, true);
6086                 if (setting)
6087                 {
6088                         values[1] = PointerGetDatum(cstring_to_text(setting));
6089                         isnull[1] = false;
6090                 }
6091                 else
6092                 {
6093                         values[1] = PointerGetDatum(NULL);
6094                         isnull[1] = true;
6095                 }
6096
6097                 values[2] = PointerGetDatum(cstring_to_text(conf->short_desc));
6098
6099                 /* send it to dest */
6100                 do_tup_output(tstate, values, isnull);
6101
6102                 /* clean up */
6103                 pfree(DatumGetPointer(values[0]));
6104                 if (setting)
6105                 {
6106                         pfree(setting);
6107                         pfree(DatumGetPointer(values[1]));
6108                 }
6109                 pfree(DatumGetPointer(values[2]));
6110         }
6111
6112         end_tup_output(tstate);
6113 }
6114
6115 /*
6116  * Return GUC variable value by name; optionally return canonical
6117  * form of name.  Return value is palloc'd.
6118  */
6119 char *
6120 GetConfigOptionByName(const char *name, const char **varname)
6121 {
6122         struct config_generic *record;
6123
6124         record = find_option(name, false, ERROR);
6125         if (record == NULL)
6126                 ereport(ERROR,
6127                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
6128                            errmsg("unrecognized configuration parameter \"%s\"", name)));
6129         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
6130                 ereport(ERROR,
6131                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
6132                                  errmsg("must be superuser to examine \"%s\"", name)));
6133
6134         if (varname)
6135                 *varname = record->name;
6136
6137         return _ShowOption(record, true);
6138 }
6139
6140 /*
6141  * Return GUC variable value by variable number; optionally return canonical
6142  * form of name.  Return value is palloc'd.
6143  */
6144 void
6145 GetConfigOptionByNum(int varnum, const char **values, bool *noshow)
6146 {
6147         char            buffer[256];
6148         struct config_generic *conf;
6149
6150         /* check requested variable number valid */
6151         Assert((varnum >= 0) && (varnum < num_guc_variables));
6152
6153         conf = guc_variables[varnum];
6154
6155         if (noshow)
6156         {
6157                 if ((conf->flags & GUC_NO_SHOW_ALL) ||
6158                         ((conf->flags & GUC_SUPERUSER_ONLY) && !superuser()))
6159                         *noshow = true;
6160                 else
6161                         *noshow = false;
6162         }
6163
6164         /* first get the generic attributes */
6165
6166         /* name */
6167         values[0] = conf->name;
6168
6169         /* setting : use _ShowOption in order to avoid duplicating the logic */
6170         values[1] = _ShowOption(conf, false);
6171
6172         /* unit */
6173         if (conf->vartype == PGC_INT)
6174         {
6175                 static char buf[8];
6176
6177                 switch (conf->flags & (GUC_UNIT_MEMORY | GUC_UNIT_TIME))
6178                 {
6179                         case GUC_UNIT_KB:
6180                                 values[2] = "kB";
6181                                 break;
6182                         case GUC_UNIT_BLOCKS:
6183                                 snprintf(buf, sizeof(buf), "%dkB", BLCKSZ / 1024);
6184                                 values[2] = buf;
6185                                 break;
6186                         case GUC_UNIT_XBLOCKS:
6187                                 snprintf(buf, sizeof(buf), "%dkB", XLOG_BLCKSZ / 1024);
6188                                 values[2] = buf;
6189                                 break;
6190                         case GUC_UNIT_MS:
6191                                 values[2] = "ms";
6192                                 break;
6193                         case GUC_UNIT_S:
6194                                 values[2] = "s";
6195                                 break;
6196                         case GUC_UNIT_MIN:
6197                                 values[2] = "min";
6198                                 break;
6199                         default:
6200                                 values[2] = "";
6201                                 break;
6202                 }
6203         }
6204         else
6205                 values[2] = NULL;
6206
6207         /* group */
6208         values[3] = config_group_names[conf->group];
6209
6210         /* short_desc */
6211         values[4] = conf->short_desc;
6212
6213         /* extra_desc */
6214         values[5] = conf->long_desc;
6215
6216         /* context */
6217         values[6] = GucContext_Names[conf->context];
6218
6219         /* vartype */
6220         values[7] = config_type_names[conf->vartype];
6221
6222         /* source */
6223         values[8] = GucSource_Names[conf->source];
6224
6225         /* now get the type specifc attributes */
6226         switch (conf->vartype)
6227         {
6228                 case PGC_BOOL:
6229                         {
6230                                 struct config_bool *lconf = (struct config_bool *) conf;
6231
6232                                 /* min_val */
6233                                 values[9] = NULL;
6234
6235                                 /* max_val */
6236                                 values[10] = NULL;
6237
6238                                 /* enumvals */
6239                                 values[11] = NULL;
6240
6241                                 /* boot_val */
6242                                 values[12] = pstrdup(lconf->boot_val ? "on" : "off");
6243
6244                                 /* reset_val */
6245                                 values[13] = pstrdup(lconf->reset_val ? "on" : "off");
6246                         }
6247                         break;
6248
6249                 case PGC_INT:
6250                         {
6251                                 struct config_int *lconf = (struct config_int *) conf;
6252
6253                                 /* min_val */
6254                                 snprintf(buffer, sizeof(buffer), "%d", lconf->min);
6255                                 values[9] = pstrdup(buffer);
6256
6257                                 /* max_val */
6258                                 snprintf(buffer, sizeof(buffer), "%d", lconf->max);
6259                                 values[10] = pstrdup(buffer);
6260
6261                                 /* enumvals */
6262                                 values[11] = NULL;
6263
6264                                 /* boot_val */
6265                                 snprintf(buffer, sizeof(buffer), "%d", lconf->boot_val);
6266                                 values[12] = pstrdup(buffer);
6267
6268                                 /* reset_val */
6269                                 snprintf(buffer, sizeof(buffer), "%d", lconf->reset_val);
6270                                 values[13] = pstrdup(buffer);
6271                         }
6272                         break;
6273
6274                 case PGC_REAL:
6275                         {
6276                                 struct config_real *lconf = (struct config_real *) conf;
6277
6278                                 /* min_val */
6279                                 snprintf(buffer, sizeof(buffer), "%g", lconf->min);
6280                                 values[9] = pstrdup(buffer);
6281
6282                                 /* max_val */
6283                                 snprintf(buffer, sizeof(buffer), "%g", lconf->max);
6284                                 values[10] = pstrdup(buffer);
6285
6286                                 /* enumvals */
6287                                 values[11] = NULL;
6288
6289                                 /* boot_val */
6290                                 snprintf(buffer, sizeof(buffer), "%g", lconf->boot_val);
6291                                 values[12] = pstrdup(buffer);
6292
6293                                 /* reset_val */
6294                                 snprintf(buffer, sizeof(buffer), "%g", lconf->reset_val);
6295                                 values[13] = pstrdup(buffer);
6296                         }
6297                         break;
6298
6299                 case PGC_STRING:
6300                         {
6301                                 struct config_string *lconf = (struct config_string *) conf;
6302
6303                                 /* min_val */
6304                                 values[9] = NULL;
6305
6306                                 /* max_val */
6307                                 values[10] = NULL;
6308
6309                                 /* enumvals */
6310                                 values[11] = NULL;
6311
6312                                 /* boot_val */
6313                                 if (lconf->boot_val == NULL)
6314                                         values[12] = NULL;
6315                                 else
6316                                         values[12] = pstrdup(lconf->boot_val);
6317
6318                                 /* reset_val */
6319                                 if (lconf->reset_val == NULL)
6320                                         values[13] = NULL;
6321                                 else
6322                                         values[13] = pstrdup(lconf->reset_val);
6323                         }
6324                         break;
6325
6326                 case PGC_ENUM:
6327                         {
6328                                 struct config_enum *lconf = (struct config_enum *) conf;
6329
6330                                 /* min_val */
6331                                 values[9] = NULL;
6332
6333                                 /* max_val */
6334                                 values[10] = NULL;
6335
6336                                 /* enumvals */
6337
6338                                 /*
6339                                  * NOTE! enumvals with double quotes in them are not
6340                                  * supported!
6341                                  */
6342                                 values[11] = config_enum_get_options((struct config_enum *) conf,
6343                                                                                                          "{\"", "\"}", "\",\"");
6344
6345                                 /* boot_val */
6346                                 values[12] = pstrdup(config_enum_lookup_by_value(lconf,
6347                                                                                                                    lconf->boot_val));
6348
6349                                 /* reset_val */
6350                                 values[13] = pstrdup(config_enum_lookup_by_value(lconf,
6351                                                                                                                   lconf->reset_val));
6352                         }
6353                         break;
6354
6355                 default:
6356                         {
6357                                 /*
6358                                  * should never get here, but in case we do, set 'em to NULL
6359                                  */
6360
6361                                 /* min_val */
6362                                 values[9] = NULL;
6363
6364                                 /* max_val */
6365                                 values[10] = NULL;
6366
6367                                 /* enumvals */
6368                                 values[11] = NULL;
6369
6370                                 /* boot_val */
6371                                 values[12] = NULL;
6372
6373                                 /* reset_val */
6374                                 values[13] = NULL;
6375                         }
6376                         break;
6377         }
6378
6379         /*
6380          * If the setting came from a config file, set the source location. For
6381          * security reasons, we don't show source file/line number for
6382          * non-superusers.
6383          */
6384         if (conf->source == PGC_S_FILE && superuser())
6385         {
6386                 values[14] = conf->sourcefile;
6387                 snprintf(buffer, sizeof(buffer), "%d", conf->sourceline);
6388                 values[15] = pstrdup(buffer);
6389         }
6390         else
6391         {
6392                 values[14] = NULL;
6393                 values[15] = NULL;
6394         }
6395 }
6396
6397 /*
6398  * Return the total number of GUC variables
6399  */
6400 int
6401 GetNumConfigOptions(void)
6402 {
6403         return num_guc_variables;
6404 }
6405
6406 /*
6407  * show_config_by_name - equiv to SHOW X command but implemented as
6408  * a function.
6409  */
6410 Datum
6411 show_config_by_name(PG_FUNCTION_ARGS)
6412 {
6413         char       *varname;
6414         char       *varval;
6415
6416         /* Get the GUC variable name */
6417         varname = TextDatumGetCString(PG_GETARG_DATUM(0));
6418
6419         /* Get the value */
6420         varval = GetConfigOptionByName(varname, NULL);
6421
6422         /* Convert to text */
6423         PG_RETURN_TEXT_P(cstring_to_text(varval));
6424 }
6425
6426 /*
6427  * show_all_settings - equiv to SHOW ALL command but implemented as
6428  * a Table Function.
6429  */
6430 #define NUM_PG_SETTINGS_ATTS    16
6431
6432 Datum
6433 show_all_settings(PG_FUNCTION_ARGS)
6434 {
6435         FuncCallContext *funcctx;
6436         TupleDesc       tupdesc;
6437         int                     call_cntr;
6438         int                     max_calls;
6439         AttInMetadata *attinmeta;
6440         MemoryContext oldcontext;
6441
6442         /* stuff done only on the first call of the function */
6443         if (SRF_IS_FIRSTCALL())
6444         {
6445                 /* create a function context for cross-call persistence */
6446                 funcctx = SRF_FIRSTCALL_INIT();
6447
6448                 /*
6449                  * switch to memory context appropriate for multiple function calls
6450                  */
6451                 oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
6452
6453                 /*
6454                  * need a tuple descriptor representing NUM_PG_SETTINGS_ATTS columns
6455                  * of the appropriate types
6456                  */
6457                 tupdesc = CreateTemplateTupleDesc(NUM_PG_SETTINGS_ATTS, false);
6458                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
6459                                                    TEXTOID, -1, 0);
6460                 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
6461                                                    TEXTOID, -1, 0);
6462                 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "unit",
6463                                                    TEXTOID, -1, 0);
6464                 TupleDescInitEntry(tupdesc, (AttrNumber) 4, "category",
6465                                                    TEXTOID, -1, 0);
6466                 TupleDescInitEntry(tupdesc, (AttrNumber) 5, "short_desc",
6467                                                    TEXTOID, -1, 0);
6468                 TupleDescInitEntry(tupdesc, (AttrNumber) 6, "extra_desc",
6469                                                    TEXTOID, -1, 0);
6470                 TupleDescInitEntry(tupdesc, (AttrNumber) 7, "context",
6471                                                    TEXTOID, -1, 0);
6472                 TupleDescInitEntry(tupdesc, (AttrNumber) 8, "vartype",
6473                                                    TEXTOID, -1, 0);
6474                 TupleDescInitEntry(tupdesc, (AttrNumber) 9, "source",
6475                                                    TEXTOID, -1, 0);
6476                 TupleDescInitEntry(tupdesc, (AttrNumber) 10, "min_val",
6477                                                    TEXTOID, -1, 0);
6478                 TupleDescInitEntry(tupdesc, (AttrNumber) 11, "max_val",
6479                                                    TEXTOID, -1, 0);
6480                 TupleDescInitEntry(tupdesc, (AttrNumber) 12, "enumvals",
6481                                                    TEXTARRAYOID, -1, 0);
6482                 TupleDescInitEntry(tupdesc, (AttrNumber) 13, "boot_val",
6483                                                    TEXTOID, -1, 0);
6484                 TupleDescInitEntry(tupdesc, (AttrNumber) 14, "reset_val",
6485                                                    TEXTOID, -1, 0);
6486                 TupleDescInitEntry(tupdesc, (AttrNumber) 15, "sourcefile",
6487                                                    TEXTOID, -1, 0);
6488                 TupleDescInitEntry(tupdesc, (AttrNumber) 16, "sourceline",
6489                                                    INT4OID, -1, 0);
6490
6491                 /*
6492                  * Generate attribute metadata needed later to produce tuples from raw
6493                  * C strings
6494                  */
6495                 attinmeta = TupleDescGetAttInMetadata(tupdesc);
6496                 funcctx->attinmeta = attinmeta;
6497
6498                 /* total number of tuples to be returned */
6499                 funcctx->max_calls = GetNumConfigOptions();
6500
6501                 MemoryContextSwitchTo(oldcontext);
6502         }
6503
6504         /* stuff done on every call of the function */
6505         funcctx = SRF_PERCALL_SETUP();
6506
6507         call_cntr = funcctx->call_cntr;
6508         max_calls = funcctx->max_calls;
6509         attinmeta = funcctx->attinmeta;
6510
6511         if (call_cntr < max_calls)      /* do when there is more left to send */
6512         {
6513                 char       *values[NUM_PG_SETTINGS_ATTS];
6514                 bool            noshow;
6515                 HeapTuple       tuple;
6516                 Datum           result;
6517
6518                 /*
6519                  * Get the next visible GUC variable name and value
6520                  */
6521                 do
6522                 {
6523                         GetConfigOptionByNum(call_cntr, (const char **) values, &noshow);
6524                         if (noshow)
6525                         {
6526                                 /* bump the counter and get the next config setting */
6527                                 call_cntr = ++funcctx->call_cntr;
6528
6529                                 /* make sure we haven't gone too far now */
6530                                 if (call_cntr >= max_calls)
6531                                         SRF_RETURN_DONE(funcctx);
6532                         }
6533                 } while (noshow);
6534
6535                 /* build a tuple */
6536                 tuple = BuildTupleFromCStrings(attinmeta, values);
6537
6538                 /* make the tuple into a datum */
6539                 result = HeapTupleGetDatum(tuple);
6540
6541                 SRF_RETURN_NEXT(funcctx, result);
6542         }
6543         else
6544         {
6545                 /* do when there is no more left */
6546                 SRF_RETURN_DONE(funcctx);
6547         }
6548 }
6549
6550 static char *
6551 _ShowOption(struct config_generic * record, bool use_units)
6552 {
6553         char            buffer[256];
6554         const char *val;
6555
6556         switch (record->vartype)
6557         {
6558                 case PGC_BOOL:
6559                         {
6560                                 struct config_bool *conf = (struct config_bool *) record;
6561
6562                                 if (conf->show_hook)
6563                                         val = (*conf->show_hook) ();
6564                                 else
6565                                         val = *conf->variable ? "on" : "off";
6566                         }
6567                         break;
6568
6569                 case PGC_INT:
6570                         {
6571                                 struct config_int *conf = (struct config_int *) record;
6572
6573                                 if (conf->show_hook)
6574                                         val = (*conf->show_hook) ();
6575                                 else
6576                                 {
6577                                         /*
6578                                          * Use int64 arithmetic to avoid overflows in units
6579                                          * conversion.  If INT64_IS_BUSTED we might overflow
6580                                          * anyway and print bogus answers, but there are few
6581                                          * enough such machines that it doesn't seem worth trying
6582                                          * harder.
6583                                          */
6584                                         int64           result = *conf->variable;
6585                                         const char *unit;
6586
6587                                         if (use_units && result > 0 &&
6588                                                 (record->flags & GUC_UNIT_MEMORY))
6589                                         {
6590                                                 switch (record->flags & GUC_UNIT_MEMORY)
6591                                                 {
6592                                                         case GUC_UNIT_BLOCKS:
6593                                                                 result *= BLCKSZ / 1024;
6594                                                                 break;
6595                                                         case GUC_UNIT_XBLOCKS:
6596                                                                 result *= XLOG_BLCKSZ / 1024;
6597                                                                 break;
6598                                                 }
6599
6600                                                 if (result % KB_PER_GB == 0)
6601                                                 {
6602                                                         result /= KB_PER_GB;
6603                                                         unit = "GB";
6604                                                 }
6605                                                 else if (result % KB_PER_MB == 0)
6606                                                 {
6607                                                         result /= KB_PER_MB;
6608                                                         unit = "MB";
6609                                                 }
6610                                                 else
6611                                                 {
6612                                                         unit = "kB";
6613                                                 }
6614                                         }
6615                                         else if (use_units && result > 0 &&
6616                                                          (record->flags & GUC_UNIT_TIME))
6617                                         {
6618                                                 switch (record->flags & GUC_UNIT_TIME)
6619                                                 {
6620                                                         case GUC_UNIT_S:
6621                                                                 result *= MS_PER_S;
6622                                                                 break;
6623                                                         case GUC_UNIT_MIN:
6624                                                                 result *= MS_PER_MIN;
6625                                                                 break;
6626                                                 }
6627
6628                                                 if (result % MS_PER_D == 0)
6629                                                 {
6630                                                         result /= MS_PER_D;
6631                                                         unit = "d";
6632                                                 }
6633                                                 else if (result % MS_PER_H == 0)
6634                                                 {
6635                                                         result /= MS_PER_H;
6636                                                         unit = "h";
6637                                                 }
6638                                                 else if (result % MS_PER_MIN == 0)
6639                                                 {
6640                                                         result /= MS_PER_MIN;
6641                                                         unit = "min";
6642                                                 }
6643                                                 else if (result % MS_PER_S == 0)
6644                                                 {
6645                                                         result /= MS_PER_S;
6646                                                         unit = "s";
6647                                                 }
6648                                                 else
6649                                                 {
6650                                                         unit = "ms";
6651                                                 }
6652                                         }
6653                                         else
6654                                                 unit = "";
6655
6656                                         snprintf(buffer, sizeof(buffer), INT64_FORMAT "%s",
6657                                                          result, unit);
6658                                         val = buffer;
6659                                 }
6660                         }
6661                         break;
6662
6663                 case PGC_REAL:
6664                         {
6665                                 struct config_real *conf = (struct config_real *) record;
6666
6667                                 if (conf->show_hook)
6668                                         val = (*conf->show_hook) ();
6669                                 else
6670                                 {
6671                                         snprintf(buffer, sizeof(buffer), "%g",
6672                                                          *conf->variable);
6673                                         val = buffer;
6674                                 }
6675                         }
6676                         break;
6677
6678                 case PGC_STRING:
6679                         {
6680                                 struct config_string *conf = (struct config_string *) record;
6681
6682                                 if (conf->show_hook)
6683                                         val = (*conf->show_hook) ();
6684                                 else if (*conf->variable && **conf->variable)
6685                                         val = *conf->variable;
6686                                 else
6687                                         val = "";
6688                         }
6689                         break;
6690
6691                 case PGC_ENUM:
6692                         {
6693                                 struct config_enum *conf = (struct config_enum *) record;
6694
6695                                 if (conf->show_hook)
6696                                         val = (*conf->show_hook) ();
6697                                 else
6698                                         val = config_enum_lookup_by_value(conf, *conf->variable);
6699                         }
6700                         break;
6701
6702                 default:
6703                         /* just to keep compiler quiet */
6704                         val = "???";
6705                         break;
6706         }
6707
6708         return pstrdup(val);
6709 }
6710
6711
6712 /*
6713  * Attempt (badly) to detect if a proposed new GUC setting is the same
6714  * as the current value.
6715  *
6716  * XXX this does not really work because it doesn't account for the
6717  * effects of canonicalization of string values by assign_hooks.
6718  */
6719 static bool
6720 is_newvalue_equal(struct config_generic * record, const char *newvalue)
6721 {
6722         /* newvalue == NULL isn't supported */
6723         Assert(newvalue != NULL);
6724
6725         switch (record->vartype)
6726         {
6727                 case PGC_BOOL:
6728                         {
6729                                 struct config_bool *conf = (struct config_bool *) record;
6730                                 bool            newval;
6731
6732                                 return parse_bool(newvalue, &newval)
6733                                         && *conf->variable == newval;
6734                         }
6735                 case PGC_INT:
6736                         {
6737                                 struct config_int *conf = (struct config_int *) record;
6738                                 int                     newval;
6739
6740                                 return parse_int(newvalue, &newval, record->flags, NULL)
6741                                         && *conf->variable == newval;
6742                         }
6743                 case PGC_REAL:
6744                         {
6745                                 struct config_real *conf = (struct config_real *) record;
6746                                 double          newval;
6747
6748                                 return parse_real(newvalue, &newval)
6749                                         && *conf->variable == newval;
6750                         }
6751                 case PGC_STRING:
6752                         {
6753                                 struct config_string *conf = (struct config_string *) record;
6754
6755                                 return *conf->variable != NULL &&
6756                                         strcmp(*conf->variable, newvalue) == 0;
6757                         }
6758
6759                 case PGC_ENUM:
6760                         {
6761                                 struct config_enum *conf = (struct config_enum *) record;
6762                                 int                     newval;
6763
6764                                 return config_enum_lookup_by_name(conf, newvalue, &newval) &&
6765                                         *conf->variable == newval;
6766                         }
6767         }
6768
6769         return false;
6770 }
6771
6772
6773 #ifdef EXEC_BACKEND
6774
6775 /*
6776  *      These routines dump out all non-default GUC options into a binary
6777  *      file that is read by all exec'ed backends.  The format is:
6778  *
6779  *              variable name, string, null terminated
6780  *              variable value, string, null terminated
6781  *              variable source, integer
6782  */
6783 static void
6784 write_one_nondefault_variable(FILE *fp, struct config_generic * gconf)
6785 {
6786         if (gconf->source == PGC_S_DEFAULT)
6787                 return;
6788
6789         fprintf(fp, "%s", gconf->name);
6790         fputc(0, fp);
6791
6792         switch (gconf->vartype)
6793         {
6794                 case PGC_BOOL:
6795                         {
6796                                 struct config_bool *conf = (struct config_bool *) gconf;
6797
6798                                 if (*conf->variable)
6799                                         fprintf(fp, "true");
6800                                 else
6801                                         fprintf(fp, "false");
6802                         }
6803                         break;
6804
6805                 case PGC_INT:
6806                         {
6807                                 struct config_int *conf = (struct config_int *) gconf;
6808
6809                                 fprintf(fp, "%d", *conf->variable);
6810                         }
6811                         break;
6812
6813                 case PGC_REAL:
6814                         {
6815                                 struct config_real *conf = (struct config_real *) gconf;
6816
6817                                 /* Could lose precision here? */
6818                                 fprintf(fp, "%f", *conf->variable);
6819                         }
6820                         break;
6821
6822                 case PGC_STRING:
6823                         {
6824                                 struct config_string *conf = (struct config_string *) gconf;
6825
6826                                 fprintf(fp, "%s", *conf->variable);
6827                         }
6828                         break;
6829
6830                 case PGC_ENUM:
6831                         {
6832                                 struct config_enum *conf = (struct config_enum *) gconf;
6833
6834                                 fprintf(fp, "%s",
6835                                                 config_enum_lookup_by_value(conf, *conf->variable));
6836                         }
6837                         break;
6838         }
6839
6840         fputc(0, fp);
6841
6842         fwrite(&gconf->source, sizeof(gconf->source), 1, fp);
6843 }
6844
6845 void
6846 write_nondefault_variables(GucContext context)
6847 {
6848         int                     elevel;
6849         FILE       *fp;
6850         struct config_generic *cvc_conf;
6851         int                     i;
6852
6853         Assert(context == PGC_POSTMASTER || context == PGC_SIGHUP);
6854
6855         elevel = (context == PGC_SIGHUP) ? LOG : ERROR;
6856
6857         /*
6858          * Open file
6859          */
6860         fp = AllocateFile(CONFIG_EXEC_PARAMS_NEW, "w");
6861         if (!fp)
6862         {
6863                 ereport(elevel,
6864                                 (errcode_for_file_access(),
6865                                  errmsg("could not write to file \"%s\": %m",
6866                                                 CONFIG_EXEC_PARAMS_NEW)));
6867                 return;
6868         }
6869
6870         /*
6871          * custom_variable_classes must be written out first; otherwise we might
6872          * reject custom variable values while reading the file.
6873          */
6874         cvc_conf = find_option("custom_variable_classes", false, ERROR);
6875         if (cvc_conf)
6876                 write_one_nondefault_variable(fp, cvc_conf);
6877
6878         for (i = 0; i < num_guc_variables; i++)
6879         {
6880                 struct config_generic *gconf = guc_variables[i];
6881
6882                 if (gconf != cvc_conf)
6883                         write_one_nondefault_variable(fp, gconf);
6884         }
6885
6886         if (FreeFile(fp))
6887         {
6888                 ereport(elevel,
6889                                 (errcode_for_file_access(),
6890                                  errmsg("could not write to file \"%s\": %m",
6891                                                 CONFIG_EXEC_PARAMS_NEW)));
6892                 return;
6893         }
6894
6895         /*
6896          * Put new file in place.  This could delay on Win32, but we don't hold
6897          * any exclusive locks.
6898          */
6899         rename(CONFIG_EXEC_PARAMS_NEW, CONFIG_EXEC_PARAMS);
6900 }
6901
6902
6903 /*
6904  *      Read string, including null byte from file
6905  *
6906  *      Return NULL on EOF and nothing read
6907  */
6908 static char *
6909 read_string_with_null(FILE *fp)
6910 {
6911         int                     i = 0,
6912                                 ch,
6913                                 maxlen = 256;
6914         char       *str = NULL;
6915
6916         do
6917         {
6918                 if ((ch = fgetc(fp)) == EOF)
6919                 {
6920                         if (i == 0)
6921                                 return NULL;
6922                         else
6923                                 elog(FATAL, "invalid format of exec config params file");
6924                 }
6925                 if (i == 0)
6926                         str = guc_malloc(FATAL, maxlen);
6927                 else if (i == maxlen)
6928                         str = guc_realloc(FATAL, str, maxlen *= 2);
6929                 str[i++] = ch;
6930         } while (ch != 0);
6931
6932         return str;
6933 }
6934
6935
6936 /*
6937  *      This routine loads a previous postmaster dump of its non-default
6938  *      settings.
6939  */
6940 void
6941 read_nondefault_variables(void)
6942 {
6943         FILE       *fp;
6944         char       *varname,
6945                            *varvalue;
6946         int                     varsource;
6947
6948         /*
6949          * Open file
6950          */
6951         fp = AllocateFile(CONFIG_EXEC_PARAMS, "r");
6952         if (!fp)
6953         {
6954                 /* File not found is fine */
6955                 if (errno != ENOENT)
6956                         ereport(FATAL,
6957                                         (errcode_for_file_access(),
6958                                          errmsg("could not read from file \"%s\": %m",
6959                                                         CONFIG_EXEC_PARAMS)));
6960                 return;
6961         }
6962
6963         for (;;)
6964         {
6965                 struct config_generic *record;
6966
6967                 if ((varname = read_string_with_null(fp)) == NULL)
6968                         break;
6969
6970                 if ((record = find_option(varname, true, FATAL)) == NULL)
6971                         elog(FATAL, "failed to locate variable %s in exec config params file", varname);
6972                 if ((varvalue = read_string_with_null(fp)) == NULL)
6973                         elog(FATAL, "invalid format of exec config params file");
6974                 if (fread(&varsource, sizeof(varsource), 1, fp) == 0)
6975                         elog(FATAL, "invalid format of exec config params file");
6976
6977                 (void) set_config_option(varname, varvalue, record->context,
6978                                                                  varsource, GUC_ACTION_SET, true);
6979                 free(varname);
6980                 free(varvalue);
6981         }
6982
6983         FreeFile(fp);
6984 }
6985 #endif   /* EXEC_BACKEND */
6986
6987
6988 /*
6989  * A little "long argument" simulation, although not quite GNU
6990  * compliant. Takes a string of the form "some-option=some value" and
6991  * returns name = "some_option" and value = "some value" in malloc'ed
6992  * storage. Note that '-' is converted to '_' in the option name. If
6993  * there is no '=' in the input string then value will be NULL.
6994  */
6995 void
6996 ParseLongOption(const char *string, char **name, char **value)
6997 {
6998         size_t          equal_pos;
6999         char       *cp;
7000
7001         AssertArg(string);
7002         AssertArg(name);
7003         AssertArg(value);
7004
7005         equal_pos = strcspn(string, "=");
7006
7007         if (string[equal_pos] == '=')
7008         {
7009                 *name = guc_malloc(FATAL, equal_pos + 1);
7010                 strlcpy(*name, string, equal_pos + 1);
7011
7012                 *value = guc_strdup(FATAL, &string[equal_pos + 1]);
7013         }
7014         else
7015         {
7016                 /* no equal sign in string */
7017                 *name = guc_strdup(FATAL, string);
7018                 *value = NULL;
7019         }
7020
7021         for (cp = *name; *cp; cp++)
7022                 if (*cp == '-')
7023                         *cp = '_';
7024 }
7025
7026
7027 /*
7028  * Handle options fetched from pg_database.datconfig, pg_authid.rolconfig,
7029  * pg_proc.proconfig, etc.      Caller must specify proper context/source/action.
7030  *
7031  * The array parameter must be an array of TEXT (it must not be NULL).
7032  */
7033 void
7034 ProcessGUCArray(ArrayType *array,
7035                                 GucContext context, GucSource source, GucAction action)
7036 {
7037         int                     i;
7038
7039         Assert(array != NULL);
7040         Assert(ARR_ELEMTYPE(array) == TEXTOID);
7041         Assert(ARR_NDIM(array) == 1);
7042         Assert(ARR_LBOUND(array)[0] == 1);
7043
7044         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
7045         {
7046                 Datum           d;
7047                 bool            isnull;
7048                 char       *s;
7049                 char       *name;
7050                 char       *value;
7051
7052                 d = array_ref(array, 1, &i,
7053                                           -1 /* varlenarray */ ,
7054                                           -1 /* TEXT's typlen */ ,
7055                                           false /* TEXT's typbyval */ ,
7056                                           'i' /* TEXT's typalign */ ,
7057                                           &isnull);
7058
7059                 if (isnull)
7060                         continue;
7061
7062                 s = TextDatumGetCString(d);
7063
7064                 ParseLongOption(s, &name, &value);
7065                 if (!value)
7066                 {
7067                         ereport(WARNING,
7068                                         (errcode(ERRCODE_SYNTAX_ERROR),
7069                                          errmsg("could not parse setting for parameter \"%s\"",
7070                                                         name)));
7071                         free(name);
7072                         continue;
7073                 }
7074
7075                 (void) set_config_option(name, value, context, source, action, true);
7076
7077                 free(name);
7078                 if (value)
7079                         free(value);
7080         }
7081 }
7082
7083
7084 /*
7085  * Add an entry to an option array.  The array parameter may be NULL
7086  * to indicate the current table entry is NULL.
7087  */
7088 ArrayType *
7089 GUCArrayAdd(ArrayType *array, const char *name, const char *value)
7090 {
7091         const char *varname;
7092         Datum           datum;
7093         char       *newval;
7094         ArrayType  *a;
7095
7096         Assert(name);
7097         Assert(value);
7098
7099         /* test if the option is valid */
7100         set_config_option(name, value,
7101                                           superuser() ? PGC_SUSET : PGC_USERSET,
7102                                           PGC_S_TEST, GUC_ACTION_SET, false);
7103
7104         /* convert name to canonical spelling, so we can use plain strcmp */
7105         (void) GetConfigOptionByName(name, &varname);
7106         name = varname;
7107
7108         newval = palloc(strlen(name) + 1 + strlen(value) + 1);
7109         sprintf(newval, "%s=%s", name, value);
7110         datum = CStringGetTextDatum(newval);
7111
7112         if (array)
7113         {
7114                 int                     index;
7115                 bool            isnull;
7116                 int                     i;
7117
7118                 Assert(ARR_ELEMTYPE(array) == TEXTOID);
7119                 Assert(ARR_NDIM(array) == 1);
7120                 Assert(ARR_LBOUND(array)[0] == 1);
7121
7122                 index = ARR_DIMS(array)[0] + 1; /* add after end */
7123
7124                 for (i = 1; i <= ARR_DIMS(array)[0]; i++)
7125                 {
7126                         Datum           d;
7127                         char       *current;
7128
7129                         d = array_ref(array, 1, &i,
7130                                                   -1 /* varlenarray */ ,
7131                                                   -1 /* TEXT's typlen */ ,
7132                                                   false /* TEXT's typbyval */ ,
7133                                                   'i' /* TEXT's typalign */ ,
7134                                                   &isnull);
7135                         if (isnull)
7136                                 continue;
7137                         current = TextDatumGetCString(d);
7138                         if (strncmp(current, newval, strlen(name) + 1) == 0)
7139                         {
7140                                 index = i;
7141                                 break;
7142                         }
7143                 }
7144
7145                 a = array_set(array, 1, &index,
7146                                           datum,
7147                                           false,
7148                                           -1 /* varlena array */ ,
7149                                           -1 /* TEXT's typlen */ ,
7150                                           false /* TEXT's typbyval */ ,
7151                                           'i' /* TEXT's typalign */ );
7152         }
7153         else
7154                 a = construct_array(&datum, 1,
7155                                                         TEXTOID,
7156                                                         -1, false, 'i');
7157
7158         return a;
7159 }
7160
7161
7162 /*
7163  * Delete an entry from an option array.  The array parameter may be NULL
7164  * to indicate the current table entry is NULL.  Also, if the return value
7165  * is NULL then a null should be stored.
7166  */
7167 ArrayType *
7168 GUCArrayDelete(ArrayType *array, const char *name)
7169 {
7170         const char *varname;
7171         ArrayType  *newarray;
7172         int                     i;
7173         int                     index;
7174
7175         Assert(name);
7176
7177         /* test if the option is valid */
7178         set_config_option(name, NULL,
7179                                           superuser() ? PGC_SUSET : PGC_USERSET,
7180                                           PGC_S_TEST, GUC_ACTION_SET, false);
7181
7182         /* convert name to canonical spelling, so we can use plain strcmp */
7183         (void) GetConfigOptionByName(name, &varname);
7184         name = varname;
7185
7186         /* if array is currently null, then surely nothing to delete */
7187         if (!array)
7188                 return NULL;
7189
7190         newarray = NULL;
7191         index = 1;
7192
7193         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
7194         {
7195                 Datum           d;
7196                 char       *val;
7197                 bool            isnull;
7198
7199                 d = array_ref(array, 1, &i,
7200                                           -1 /* varlenarray */ ,
7201                                           -1 /* TEXT's typlen */ ,
7202                                           false /* TEXT's typbyval */ ,
7203                                           'i' /* TEXT's typalign */ ,
7204                                           &isnull);
7205                 if (isnull)
7206                         continue;
7207                 val = TextDatumGetCString(d);
7208
7209                 /* ignore entry if it's what we want to delete */
7210                 if (strncmp(val, name, strlen(name)) == 0
7211                         && val[strlen(name)] == '=')
7212                         continue;
7213
7214                 /* else add it to the output array */
7215                 if (newarray)
7216                 {
7217                         newarray = array_set(newarray, 1, &index,
7218                                                                  d,
7219                                                                  false,
7220                                                                  -1 /* varlenarray */ ,
7221                                                                  -1 /* TEXT's typlen */ ,
7222                                                                  false /* TEXT's typbyval */ ,
7223                                                                  'i' /* TEXT's typalign */ );
7224                 }
7225                 else
7226                         newarray = construct_array(&d, 1,
7227                                                                            TEXTOID,
7228                                                                            -1, false, 'i');
7229
7230                 index++;
7231         }
7232
7233         return newarray;
7234 }
7235
7236
7237 /*
7238  * assign_hook and show_hook subroutines
7239  */
7240
7241 static const char *
7242 assign_log_destination(const char *value, bool doit, GucSource source)
7243 {
7244         char       *rawstring;
7245         List       *elemlist;
7246         ListCell   *l;
7247         int                     newlogdest = 0;
7248
7249         /* Need a modifiable copy of string */
7250         rawstring = pstrdup(value);
7251
7252         /* Parse string into list of identifiers */
7253         if (!SplitIdentifierString(rawstring, ',', &elemlist))
7254         {
7255                 /* syntax error in list */
7256                 pfree(rawstring);
7257                 list_free(elemlist);
7258                 ereport(GUC_complaint_elevel(source),
7259                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7260                    errmsg("invalid list syntax for parameter \"log_destination\"")));
7261                 return NULL;
7262         }
7263
7264         foreach(l, elemlist)
7265         {
7266                 char       *tok = (char *) lfirst(l);
7267
7268                 if (pg_strcasecmp(tok, "stderr") == 0)
7269                         newlogdest |= LOG_DESTINATION_STDERR;
7270                 else if (pg_strcasecmp(tok, "csvlog") == 0)
7271                         newlogdest |= LOG_DESTINATION_CSVLOG;
7272 #ifdef HAVE_SYSLOG
7273                 else if (pg_strcasecmp(tok, "syslog") == 0)
7274                         newlogdest |= LOG_DESTINATION_SYSLOG;
7275 #endif
7276 #ifdef WIN32
7277                 else if (pg_strcasecmp(tok, "eventlog") == 0)
7278                         newlogdest |= LOG_DESTINATION_EVENTLOG;
7279 #endif
7280                 else
7281                 {
7282                         ereport(GUC_complaint_elevel(source),
7283                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7284                                   errmsg("unrecognized \"log_destination\" key word: \"%s\"",
7285                                                  tok)));
7286                         pfree(rawstring);
7287                         list_free(elemlist);
7288                         return NULL;
7289                 }
7290         }
7291
7292         if (doit)
7293                 Log_destination = newlogdest;
7294
7295         pfree(rawstring);
7296         list_free(elemlist);
7297
7298         return value;
7299 }
7300
7301 #ifdef HAVE_SYSLOG
7302
7303 static bool
7304 assign_syslog_facility(int newval, bool doit, GucSource source)
7305 {
7306         if (doit)
7307                 set_syslog_parameters(syslog_ident_str ? syslog_ident_str : "postgres",
7308                                                           newval);
7309
7310         return true;
7311 }
7312
7313 static const char *
7314 assign_syslog_ident(const char *ident, bool doit, GucSource source)
7315 {
7316         if (doit)
7317                 set_syslog_parameters(ident, syslog_facility);
7318
7319         return ident;
7320 }
7321 #endif   /* HAVE_SYSLOG */
7322
7323
7324 static bool
7325 assign_session_replication_role(int newval, bool doit, GucSource source)
7326 {
7327         /*
7328          * Must flush the plan cache when changing replication role; but don't
7329          * flush unnecessarily.
7330          */
7331         if (doit && SessionReplicationRole != newval)
7332         {
7333                 ResetPlanCache();
7334         }
7335
7336         return true;
7337 }
7338
7339 static const char *
7340 show_num_temp_buffers(void)
7341 {
7342         /*
7343          * We show the GUC var until local buffers have been initialized, and
7344          * NLocBuffer afterwards.
7345          */
7346         static char nbuf[32];
7347
7348         sprintf(nbuf, "%d", NLocBuffer ? NLocBuffer : num_temp_buffers);
7349         return nbuf;
7350 }
7351
7352 static bool
7353 assign_phony_autocommit(bool newval, bool doit, GucSource source)
7354 {
7355         if (!newval)
7356         {
7357                 ereport(GUC_complaint_elevel(source),
7358                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
7359                                  errmsg("SET AUTOCOMMIT TO OFF is no longer supported")));
7360                 return false;
7361         }
7362         return true;
7363 }
7364
7365 static const char *
7366 assign_custom_variable_classes(const char *newval, bool doit, GucSource source)
7367 {
7368         /*
7369          * Check syntax. newval must be a comma separated list of identifiers.
7370          * Whitespace is allowed but removed from the result.
7371          */
7372         bool            hasSpaceAfterToken = false;
7373         const char *cp = newval;
7374         int                     symLen = 0;
7375         char            c;
7376         StringInfoData buf;
7377
7378         initStringInfo(&buf);
7379         while ((c = *cp++) != '\0')
7380         {
7381                 if (isspace((unsigned char) c))
7382                 {
7383                         if (symLen > 0)
7384                                 hasSpaceAfterToken = true;
7385                         continue;
7386                 }
7387
7388                 if (c == ',')
7389                 {
7390                         if (symLen > 0)         /* terminate identifier */
7391                         {
7392                                 appendStringInfoChar(&buf, ',');
7393                                 symLen = 0;
7394                         }
7395                         hasSpaceAfterToken = false;
7396                         continue;
7397                 }
7398
7399                 if (hasSpaceAfterToken || !(isalnum((unsigned char) c) || c == '_'))
7400                 {
7401                         /*
7402                          * Syntax error due to token following space after token or
7403                          * non-identifier character
7404                          */
7405                         pfree(buf.data);
7406                         return NULL;
7407                 }
7408                 appendStringInfoChar(&buf, c);
7409                 symLen++;
7410         }
7411
7412         /* Remove stray ',' at end */
7413         if (symLen == 0 && buf.len > 0)
7414                 buf.data[--buf.len] = '\0';
7415
7416         /* GUC wants the result malloc'd */
7417         newval = guc_strdup(LOG, buf.data);
7418
7419         pfree(buf.data);
7420         return newval;
7421 }
7422
7423 static bool
7424 assign_debug_assertions(bool newval, bool doit, GucSource source)
7425 {
7426 #ifndef USE_ASSERT_CHECKING
7427         if (newval)
7428         {
7429                 ereport(GUC_complaint_elevel(source),
7430                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7431                            errmsg("assertion checking is not supported by this build")));
7432                 return false;
7433         }
7434 #endif
7435         return true;
7436 }
7437
7438 static bool
7439 assign_bonjour(bool newval, bool doit, GucSource source)
7440 {
7441 #ifndef USE_BONJOUR
7442         if (newval)
7443         {
7444                 ereport(GUC_complaint_elevel(source),
7445                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7446                                  errmsg("Bonjour is not supported by this build")));
7447                 return false;
7448         }
7449 #endif
7450         return true;
7451 }
7452
7453 static bool
7454 assign_ssl(bool newval, bool doit, GucSource source)
7455 {
7456 #ifndef USE_SSL
7457         if (newval)
7458         {
7459                 ereport(GUC_complaint_elevel(source),
7460                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7461                                  errmsg("SSL is not supported by this build")));
7462                 return false;
7463         }
7464 #endif
7465         return true;
7466 }
7467
7468 static bool
7469 assign_stage_log_stats(bool newval, bool doit, GucSource source)
7470 {
7471         if (newval && log_statement_stats)
7472         {
7473                 ereport(GUC_complaint_elevel(source),
7474                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7475                                  errmsg("cannot enable parameter when \"log_statement_stats\" is true")));
7476                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7477                 if (source != PGC_S_OVERRIDE)
7478                         return false;
7479         }
7480         return true;
7481 }
7482
7483 static bool
7484 assign_log_stats(bool newval, bool doit, GucSource source)
7485 {
7486         if (newval &&
7487                 (log_parser_stats || log_planner_stats || log_executor_stats))
7488         {
7489                 ereport(GUC_complaint_elevel(source),
7490                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7491                                  errmsg("cannot enable \"log_statement_stats\" when "
7492                                                 "\"log_parser_stats\", \"log_planner_stats\", "
7493                                                 "or \"log_executor_stats\" is true")));
7494                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7495                 if (source != PGC_S_OVERRIDE)
7496                         return false;
7497         }
7498         return true;
7499 }
7500
7501 static bool
7502 assign_transaction_read_only(bool newval, bool doit, GucSource source)
7503 {
7504         /* Can't go to r/w mode inside a r/o transaction */
7505         if (newval == false && XactReadOnly && IsSubTransaction())
7506         {
7507                 ereport(GUC_complaint_elevel(source),
7508                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7509                                  errmsg("cannot set transaction read-write mode inside a read-only transaction")));
7510                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7511                 if (source != PGC_S_OVERRIDE)
7512                         return false;
7513         }
7514         return true;
7515 }
7516
7517 static const char *
7518 assign_canonical_path(const char *newval, bool doit, GucSource source)
7519 {
7520         if (doit)
7521         {
7522                 char       *canon_val = guc_strdup(ERROR, newval);
7523
7524                 canonicalize_path(canon_val);
7525                 return canon_val;
7526         }
7527         else
7528                 return newval;
7529 }
7530
7531 static const char *
7532 assign_timezone_abbreviations(const char *newval, bool doit, GucSource source)
7533 {
7534         /*
7535          * The powerup value shown above for timezone_abbreviations is "UNKNOWN".
7536          * When we see this we just do nothing.  If this value isn't overridden
7537          * from the config file then pg_timezone_abbrev_initialize() will
7538          * eventually replace it with "Default".  This hack has two purposes: to
7539          * avoid wasting cycles loading values that might soon be overridden from
7540          * the config file, and to avoid trying to read the timezone abbrev files
7541          * during InitializeGUCOptions().  The latter doesn't work in an
7542          * EXEC_BACKEND subprocess because my_exec_path hasn't been set yet and so
7543          * we can't locate PGSHAREDIR.  (Essentially the same hack is used to
7544          * delay initializing TimeZone ... if we have any more, we should try to
7545          * clean up and centralize this mechanism ...)
7546          */
7547         if (strcmp(newval, "UNKNOWN") == 0)
7548         {
7549                 return newval;
7550         }
7551
7552         /* Loading abbrev file is expensive, so only do it when value changes */
7553         if (timezone_abbreviations_string == NULL ||
7554                 strcmp(timezone_abbreviations_string, newval) != 0)
7555         {
7556                 int                     elevel;
7557
7558                 /*
7559                  * If reading config file, only the postmaster should bleat loudly
7560                  * about problems.      Otherwise, it's just this one process doing it,
7561                  * and we use WARNING message level.
7562                  */
7563                 if (source == PGC_S_FILE)
7564                         elevel = IsUnderPostmaster ? DEBUG3 : LOG;
7565                 else
7566                         elevel = WARNING;
7567                 if (!load_tzoffsets(newval, doit, elevel))
7568                         return NULL;
7569         }
7570         return newval;
7571 }
7572
7573 /*
7574  * pg_timezone_abbrev_initialize --- set default value if not done already
7575  *
7576  * This is called after initial loading of postgresql.conf.  If no
7577  * timezone_abbreviations setting was found therein, select default.
7578  */
7579 void
7580 pg_timezone_abbrev_initialize(void)
7581 {
7582         if (strcmp(timezone_abbreviations_string, "UNKNOWN") == 0)
7583         {
7584                 SetConfigOption("timezone_abbreviations", "Default",
7585                                                 PGC_POSTMASTER, PGC_S_ARGV);
7586         }
7587 }
7588
7589 static const char *
7590 show_archive_command(void)
7591 {
7592         if (XLogArchiveMode)
7593                 return XLogArchiveCommand;
7594         else
7595                 return "(disabled)";
7596 }
7597
7598 static bool
7599 assign_tcp_keepalives_idle(int newval, bool doit, GucSource source)
7600 {
7601         if (doit)
7602                 return (pq_setkeepalivesidle(newval, MyProcPort) == STATUS_OK);
7603
7604         return true;
7605 }
7606
7607 static const char *
7608 show_tcp_keepalives_idle(void)
7609 {
7610         static char nbuf[16];
7611
7612         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesidle(MyProcPort));
7613         return nbuf;
7614 }
7615
7616 static bool
7617 assign_tcp_keepalives_interval(int newval, bool doit, GucSource source)
7618 {
7619         if (doit)
7620                 return (pq_setkeepalivesinterval(newval, MyProcPort) == STATUS_OK);
7621
7622         return true;
7623 }
7624
7625 static const char *
7626 show_tcp_keepalives_interval(void)
7627 {
7628         static char nbuf[16];
7629
7630         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesinterval(MyProcPort));
7631         return nbuf;
7632 }
7633
7634 static bool
7635 assign_tcp_keepalives_count(int newval, bool doit, GucSource source)
7636 {
7637         if (doit)
7638                 return (pq_setkeepalivescount(newval, MyProcPort) == STATUS_OK);
7639
7640         return true;
7641 }
7642
7643 static const char *
7644 show_tcp_keepalives_count(void)
7645 {
7646         static char nbuf[16];
7647
7648         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivescount(MyProcPort));
7649         return nbuf;
7650 }
7651
7652 static bool
7653 assign_maxconnections(int newval, bool doit, GucSource source)
7654 {
7655         if (newval + autovacuum_max_workers + 1 > INT_MAX / 4)
7656                 return false;
7657
7658         if (doit)
7659                 MaxBackends = newval + autovacuum_max_workers + 1;
7660
7661         return true;
7662 }
7663
7664 static bool
7665 assign_autovacuum_max_workers(int newval, bool doit, GucSource source)
7666 {
7667         if (MaxConnections + newval + 1 > INT_MAX / 4)
7668                 return false;
7669
7670         if (doit)
7671                 MaxBackends = MaxConnections + newval + 1;
7672
7673         return true;
7674 }
7675
7676 static bool
7677 assign_effective_io_concurrency(int newval, bool doit, GucSource source)
7678 {
7679 #ifdef USE_PREFETCH
7680         double          new_prefetch_pages = 0.0;
7681         int                     i;
7682
7683         /*----------
7684          * The user-visible GUC parameter is the number of drives (spindles),
7685          * which we need to translate to a number-of-pages-to-prefetch target.
7686          *
7687          * The expected number of prefetch pages needed to keep N drives busy is:
7688          *
7689          * drives |   I/O requests
7690          * -------+----------------
7691          *              1 |   1
7692          *              2 |   2/1 + 2/2 = 3
7693          *              3 |   3/1 + 3/2 + 3/3 = 5 1/2
7694          *              4 |   4/1 + 4/2 + 4/3 + 4/4 = 8 1/3
7695          *              n |   n * H(n)
7696          *
7697          * This is called the "coupon collector problem" and H(n) is called the
7698          * harmonic series.  This could be approximated by n * ln(n), but for
7699          * reasonable numbers of drives we might as well just compute the series.
7700          *
7701          * Alternatively we could set the target to the number of pages necessary
7702          * so that the expected number of active spindles is some arbitrary
7703          * percentage of the total.  This sounds the same but is actually slightly
7704          * different.  The result ends up being ln(1-P)/ln((n-1)/n) where P is
7705          * that desired fraction.
7706          *
7707          * Experimental results show that both of these formulas aren't aggressive
7708          * enough, but we don't really have any better proposals.
7709          *
7710          * Note that if newval = 0 (disabled), we must set target = 0.
7711          *----------
7712          */
7713
7714         for (i = 1; i <= newval; i++)
7715                 new_prefetch_pages += (double) newval / (double) i;
7716
7717         /* This range check shouldn't fail, but let's be paranoid */
7718         if (new_prefetch_pages >= 0.0 && new_prefetch_pages < (double) INT_MAX)
7719         {
7720                 if (doit)
7721                         target_prefetch_pages = (int) rint(new_prefetch_pages);
7722                 return true;
7723         }
7724         else
7725                 return false;
7726 #else
7727         return true;
7728 #endif   /* USE_PREFETCH */
7729 }
7730
7731 static const char *
7732 assign_pgstat_temp_directory(const char *newval, bool doit, GucSource source)
7733 {
7734         if (doit)
7735         {
7736                 char       *canon_val = guc_strdup(ERROR, newval);
7737                 char       *tname;
7738                 char       *fname;
7739
7740                 canonicalize_path(canon_val);
7741
7742                 tname = guc_malloc(ERROR, strlen(canon_val) + 12);              /* /pgstat.tmp */
7743                 sprintf(tname, "%s/pgstat.tmp", canon_val);
7744                 fname = guc_malloc(ERROR, strlen(canon_val) + 13);              /* /pgstat.stat */
7745                 sprintf(fname, "%s/pgstat.stat", canon_val);
7746
7747                 if (pgstat_stat_tmpname)
7748                         free(pgstat_stat_tmpname);
7749                 pgstat_stat_tmpname = tname;
7750                 if (pgstat_stat_filename)
7751                         free(pgstat_stat_filename);
7752                 pgstat_stat_filename = fname;
7753
7754                 return canon_val;
7755         }
7756         else
7757                 return newval;
7758 }
7759
7760 static const char *
7761 assign_application_name(const char *newval, bool doit, GucSource source)
7762 {
7763         if (doit)
7764         {
7765                 /* Only allow clean ASCII chars in the application name */
7766                 char       *repval = guc_strdup(ERROR, newval);
7767                 char       *p;
7768
7769                 for (p = repval; *p; p++)
7770                 {
7771                         if (*p < 32 || *p > 126)
7772                                 *p = '?';
7773                 }
7774
7775                 /* Update the pg_stat_activity view */
7776                 pgstat_report_appname(repval);
7777
7778                 return repval;
7779         }
7780         else
7781                 return newval;
7782 }
7783
7784 #include "guc-file.c"