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 1.514 2009/08/31 19:41:00 tgl 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/pqformat.h"
  42 #include "miscadmin.h"
  43 #include "optimizer/cost.h"
  44 #include "optimizer/geqo.h"
  45 #include "optimizer/paths.h"
  46 #include "optimizer/planmain.h"
  47 #include "parser/parse_expr.h"
  48 #include "parser/parse_relation.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 "regex/regex.h"
  59 #include "storage/bufmgr.h"
  60 #include "storage/fd.h"
  61 #include "tcop/tcopprot.h"
  62 #include "tsearch/ts_cache.h"
  63 #include "utils/builtins.h"
  64 #include "utils/bytea.h"
  65 #include "utils/guc_tables.h"
  66 #include "utils/memutils.h"
  67 #include "utils/pg_locale.h"
  68 #include "utils/plancache.h"
  69 #include "utils/portal.h"
  70 #include "utils/ps_status.h"
  71 #include "utils/tzparser.h"
  72 #include "utils/xml.h"
  73
  74 #ifndef PG_KRB_SRVTAB
  75 #define PG_KRB_SRVTAB ""
  76 #endif
  77 #ifndef PG_KRB_SRVNAM
  78 #define PG_KRB_SRVNAM ""
  79 #endif
  80
  81 #define CONFIG_FILENAME "postgresql.conf"
  82 #define HBA_FILENAME    "pg_hba.conf"
  83 #define IDENT_FILENAME  "pg_ident.conf"
  84
  85 #ifdef EXEC_BACKEND
  86 #define CONFIG_EXEC_PARAMS "global/config_exec_params"
  87 #define CONFIG_EXEC_PARAMS_NEW "global/config_exec_params.new"
  88 #endif
  89
  90 /* upper limit for GUC variables measured in kilobytes of memory */
  91 #if SIZEOF_SIZE_T > 4
  92 #define MAX_KILOBYTES   INT_MAX
  93 #else
  94 #define MAX_KILOBYTES   (INT_MAX / 1024)
  95 #endif
  96
  97 #define KB_PER_MB (1024)
  98 #define KB_PER_GB (1024*1024)
  99
 100 #define MS_PER_S 1000
 101 #define S_PER_MIN 60
 102 #define MS_PER_MIN (1000 * 60)
 103 #define MIN_PER_H 60
 104 #define S_PER_H (60 * 60)
 105 #define MS_PER_H (1000 * 60 * 60)
 106 #define MIN_PER_D (60 * 24)
 107 #define S_PER_D (60 * 60 * 24)
 108 #define MS_PER_D (1000 * 60 * 60 * 24)
 109
 110 /* XXX these should appear in other modules' header files */
 111 extern bool Log_disconnections;
 112 extern int      CommitDelay;
 113 extern int      CommitSiblings;
 114 extern char *default_tablespace;
 115 extern char *temp_tablespaces;
 116 extern bool synchronize_seqscans;
 117 extern bool fullPageWrites;
 118
 119 #ifdef TRACE_SORT
 120 extern bool trace_sort;
 121 #endif
 122 #ifdef TRACE_SYNCSCAN
 123 extern bool trace_syncscan;
 124 #endif
 125 #ifdef DEBUG_BOUNDED_SORT
 126 extern bool optimize_bounded_sort;
 127 #endif
 128
 129 #ifdef USE_SSL
 130 extern char *SSLCipherSuites;
 131 #endif
 132
 133 static void set_config_sourcefile(const char *name, char *sourcefile,
 134                                           int sourceline);
 135
 136 static const char *assign_log_destination(const char *value,
 137                                            bool doit, GucSource source);
 138
 139 #ifdef HAVE_SYSLOG
 140 static int      syslog_facility = LOG_LOCAL0;
 141
 142 static bool assign_syslog_facility(int newval,
 143                                            bool doit, GucSource source);
 144 static const char *assign_syslog_ident(const char *ident,
 145                                         bool doit, GucSource source);
 146 #endif
 147
 148 static bool assign_session_replication_role(int newval, bool doit,
 149                                                                 GucSource source);
 150 static const char *show_num_temp_buffers(void);
 151 static bool assign_phony_autocommit(bool newval, bool doit, GucSource source);
 152 static const char *assign_custom_variable_classes(const char *newval, bool doit,
 153                                                            GucSource source);
 154 static bool assign_debug_assertions(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
 173 static char *config_enum_get_options(struct config_enum * record,
 174                                                 const char *prefix, const char *suffix,
 175                                                 const char *separator);
 176
 177
 178 /*
 179  * Options for enum values defined in this module.
 180  *
 181  * NOTE! Option values may not contain double quotes!
 182  */
 183
 184 static const struct config_enum_entry bytea_output_options[] = {
 185         {"escape", BYTEA_OUTPUT_ESCAPE, false},
 186         {"hex", BYTEA_OUTPUT_HEX, false},
 187         {NULL, 0, false}
 188 };
 189
 190 /*
 191  * We have different sets for client and server message level options because
 192  * they sort slightly different (see "log" level)
 193  */
 194 static const struct config_enum_entry client_message_level_options[] = {
 195         {"debug", DEBUG2, true},
 196         {"debug5", DEBUG5, false},
 197         {"debug4", DEBUG4, false},
 198         {"debug3", DEBUG3, false},
 199         {"debug2", DEBUG2, false},
 200         {"debug1", DEBUG1, false},
 201         {"log", LOG, false},
 202         {"info", INFO, true},
 203         {"notice", NOTICE, false},
 204         {"warning", WARNING, false},
 205         {"error", ERROR, false},
 206         {"fatal", FATAL, true},
 207         {"panic", PANIC, true},
 208         {NULL, 0, false}
 209 };
 210
 211 static const struct config_enum_entry server_message_level_options[] = {
 212         {"debug", DEBUG2, true},
 213         {"debug5", DEBUG5, false},
 214         {"debug4", DEBUG4, false},
 215         {"debug3", DEBUG3, false},
 216         {"debug2", DEBUG2, false},
 217         {"debug1", DEBUG1, false},
 218         {"info", INFO, false},
 219         {"notice", NOTICE, false},
 220         {"warning", WARNING, false},
 221         {"error", ERROR, false},
 222         {"log", LOG, false},
 223         {"fatal", FATAL, false},
 224         {"panic", PANIC, false},
 225         {NULL, 0, false}
 226 };
 227
 228 static const struct config_enum_entry intervalstyle_options[] = {
 229         {"postgres", INTSTYLE_POSTGRES, false},
 230         {"postgres_verbose", INTSTYLE_POSTGRES_VERBOSE, false},
 231         {"sql_standard", INTSTYLE_SQL_STANDARD, false},
 232         {"iso_8601", INTSTYLE_ISO_8601, false},
 233         {NULL, 0, false}
 234 };
 235
 236 static const struct config_enum_entry log_error_verbosity_options[] = {
 237         {"terse", PGERROR_TERSE, false},
 238         {"default", PGERROR_DEFAULT, false},
 239         {"verbose", PGERROR_VERBOSE, false},
 240         {NULL, 0, false}
 241 };
 242
 243 static const struct config_enum_entry log_statement_options[] = {
 244         {"none", LOGSTMT_NONE, false},
 245         {"ddl", LOGSTMT_DDL, false},
 246         {"mod", LOGSTMT_MOD, false},
 247         {"all", LOGSTMT_ALL, false},
 248         {NULL, 0, false}
 249 };
 250
 251 static const struct config_enum_entry regex_flavor_options[] = {
 252         {"advanced", REG_ADVANCED, false},
 253         {"extended", REG_EXTENDED, false},
 254         {"basic", REG_BASIC, false},
 255         {NULL, 0, false}
 256 };
 257
 258 static const struct config_enum_entry isolation_level_options[] = {
 259         {"serializable", XACT_SERIALIZABLE, false},
 260         {"repeatable read", XACT_REPEATABLE_READ, false},
 261         {"read committed", XACT_READ_COMMITTED, false},
 262         {"read uncommitted", XACT_READ_UNCOMMITTED, false},
 263         {NULL, 0}
 264 };
 265
 266 static const struct config_enum_entry session_replication_role_options[] = {
 267         {"origin", SESSION_REPLICATION_ROLE_ORIGIN, false},
 268         {"replica", SESSION_REPLICATION_ROLE_REPLICA, false},
 269         {"local", SESSION_REPLICATION_ROLE_LOCAL, false},
 270         {NULL, 0, false}
 271 };
 272
 273 #ifdef HAVE_SYSLOG
 274 static const struct config_enum_entry syslog_facility_options[] = {
 275         {"local0", LOG_LOCAL0, false},
 276         {"local1", LOG_LOCAL1, false},
 277         {"local2", LOG_LOCAL2, false},
 278         {"local3", LOG_LOCAL3, false},
 279         {"local4", LOG_LOCAL4, false},
 280         {"local5", LOG_LOCAL5, false},
 281         {"local6", LOG_LOCAL6, false},
 282         {"local7", LOG_LOCAL7, false},
 283         {NULL, 0}
 284 };
 285 #endif
 286
 287 static const struct config_enum_entry track_function_options[] = {
 288         {"none", TRACK_FUNC_OFF, false},
 289         {"pl", TRACK_FUNC_PL, false},
 290         {"all", TRACK_FUNC_ALL, false},
 291         {NULL, 0, false}
 292 };
 293
 294 static const struct config_enum_entry xmlbinary_options[] = {
 295         {"base64", XMLBINARY_BASE64, false},
 296         {"hex", XMLBINARY_HEX, false},
 297         {NULL, 0, false}
 298 };
 299
 300 static const struct config_enum_entry xmloption_options[] = {
 301         {"content", XMLOPTION_CONTENT, false},
 302         {"document", XMLOPTION_DOCUMENT, false},
 303         {NULL, 0, false}
 304 };
 305
 306 /*
 307  * Although only "on", "off", and "safe_encoding" are documented, we
 308  * accept all the likely variants of "on" and "off".
 309  */
 310 static const struct config_enum_entry backslash_quote_options[] = {
 311         {"safe_encoding", BACKSLASH_QUOTE_SAFE_ENCODING, false},
 312         {"on", BACKSLASH_QUOTE_ON, false},
 313         {"off", BACKSLASH_QUOTE_OFF, false},
 314         {"true", BACKSLASH_QUOTE_ON, true},
 315         {"false", BACKSLASH_QUOTE_OFF, true},
 316         {"yes", BACKSLASH_QUOTE_ON, true},
 317         {"no", BACKSLASH_QUOTE_OFF, true},
 318         {"1", BACKSLASH_QUOTE_ON, true},
 319         {"0", BACKSLASH_QUOTE_OFF, true},
 320         {NULL, 0, false}
 321 };
 322
 323 /*
 324  * Although only "on", "off", and "partition" are documented, we
 325  * accept all the likely variants of "on" and "off".
 326  */
 327 static const struct config_enum_entry constraint_exclusion_options[] = {
 328         {"partition", CONSTRAINT_EXCLUSION_PARTITION, false},
 329         {"on", CONSTRAINT_EXCLUSION_ON, false},
 330         {"off", CONSTRAINT_EXCLUSION_OFF, false},
 331         {"true", CONSTRAINT_EXCLUSION_ON, true},
 332         {"false", CONSTRAINT_EXCLUSION_OFF, true},
 333         {"yes", CONSTRAINT_EXCLUSION_ON, true},
 334         {"no", CONSTRAINT_EXCLUSION_OFF, true},
 335         {"1", CONSTRAINT_EXCLUSION_ON, true},
 336         {"0", CONSTRAINT_EXCLUSION_OFF, true},
 337         {NULL, 0, false}
 338 };
 339
 340 /*
 341  * Options for enum values stored in other modules
 342  */
 343 extern const struct config_enum_entry sync_method_options[];
 344
 345 /*
 346  * GUC option variables that are exported from this module
 347  */
 348 #ifdef USE_ASSERT_CHECKING
 349 bool            assert_enabled = true;
 350 #else
 351 bool            assert_enabled = false;
 352 #endif
 353 bool            log_duration = false;
 354 bool            Debug_print_plan = false;
 355 bool            Debug_print_parse = false;
 356 bool            Debug_print_rewritten = false;
 357 bool            Debug_pretty_print = true;
 358
 359 bool            log_parser_stats = false;
 360 bool            log_planner_stats = false;
 361 bool            log_executor_stats = false;
 362 bool            log_statement_stats = false;            /* this is sort of all three
 363                                                                                                  * above together */
 364 bool            log_btree_build_stats = false;
 365
 366 bool            check_function_bodies = true;
 367 bool            default_with_oids = false;
 368 bool            SQL_inheritance = true;
 369
 370 bool            Password_encryption = true;
 371
 372 int                     log_min_error_statement = ERROR;
 373 int                     log_min_messages = WARNING;
 374 int                     client_min_messages = NOTICE;
 375 int                     log_min_duration_statement = -1;
 376 int                     log_temp_files = -1;
 377
 378 int                     num_temp_buffers = 1000;
 379
 380 char       *ConfigFileName;
 381 char       *HbaFileName;
 382 char       *IdentFileName;
 383 char       *external_pid_file;
 384
 385 char       *pgstat_temp_directory;
 386
 387 int                     tcp_keepalives_idle;
 388 int                     tcp_keepalives_interval;
 389 int                     tcp_keepalives_count;
 390
 391 /*
 392  * These variables are all dummies that don't do anything, except in some
 393  * cases provide the value for SHOW to display.  The real state is elsewhere
 394  * and is kept in sync by assign_hooks.
 395  */
 396 static char *log_destination_string;
 397
 398 #ifdef HAVE_SYSLOG
 399 static char *syslog_ident_str;
 400 #endif
 401 static bool phony_autocommit;
 402 static bool session_auth_is_superuser;
 403 static double phony_random_seed;
 404 static char *client_encoding_string;
 405 static char *datestyle_string;
 406 static char *locale_collate;
 407 static char *locale_ctype;
 408 static char *server_encoding_string;
 409 static char *server_version_string;
 410 static int      server_version_num;
 411 static char *timezone_string;
 412 static char *log_timezone_string;
 413 static char *timezone_abbreviations_string;
 414 static char *XactIsoLevel_string;
 415 static char *data_directory;
 416 static char *custom_variable_classes;
 417 static int      max_function_args;
 418 static int      max_index_keys;
 419 static int      max_identifier_length;
 420 static int      block_size;
 421 static int      segment_size;
 422 static int      wal_block_size;
 423 static int      wal_segment_size;
 424 static bool integer_datetimes;
 425 static int      effective_io_concurrency;
 426
 427 /* should be static, but commands/variable.c needs to get at these */
 428 char       *role_string;
 429 char       *session_authorization_string;
 430
 431
 432 /*
 433  * Displayable names for context types (enum GucContext)
 434  *
 435  * Note: these strings are deliberately not localized.
 436  */
 437 const char *const GucContext_Names[] =
 438 {
 439          /* PGC_INTERNAL */ "internal",
 440          /* PGC_POSTMASTER */ "postmaster",
 441          /* PGC_SIGHUP */ "sighup",
 442          /* PGC_BACKEND */ "backend",
 443          /* PGC_SUSET */ "superuser",
 444          /* PGC_USERSET */ "user"
 445 };
 446
 447 /*
 448  * Displayable names for source types (enum GucSource)
 449  *
 450  * Note: these strings are deliberately not localized.
 451  */
 452 const char *const GucSource_Names[] =
 453 {
 454          /* PGC_S_DEFAULT */ "default",
 455          /* PGC_S_ENV_VAR */ "environment variable",
 456          /* PGC_S_FILE */ "configuration file",
 457          /* PGC_S_ARGV */ "command line",
 458          /* PGC_S_DATABASE */ "database",
 459          /* PGC_S_USER */ "user",
 460          /* PGC_S_CLIENT */ "client",
 461          /* PGC_S_OVERRIDE */ "override",
 462          /* PGC_S_INTERACTIVE */ "interactive",
 463          /* PGC_S_TEST */ "test",
 464          /* PGC_S_SESSION */ "session"
 465 };
 466
 467 /*
 468  * Displayable names for the groupings defined in enum config_group
 469  */
 470 const char *const config_group_names[] =
 471 {
 472         /* UNGROUPED */
 473         gettext_noop("Ungrouped"),
 474         /* FILE_LOCATIONS */
 475         gettext_noop("File Locations"),
 476         /* CONN_AUTH */
 477         gettext_noop("Connections and Authentication"),
 478         /* CONN_AUTH_SETTINGS */
 479         gettext_noop("Connections and Authentication / Connection Settings"),
 480         /* CONN_AUTH_SECURITY */
 481         gettext_noop("Connections and Authentication / Security and Authentication"),
 482         /* RESOURCES */
 483         gettext_noop("Resource Usage"),
 484         /* RESOURCES_MEM */
 485         gettext_noop("Resource Usage / Memory"),
 486         /* RESOURCES_KERNEL */
 487         gettext_noop("Resource Usage / Kernel Resources"),
 488         /* WAL */
 489         gettext_noop("Write-Ahead Log"),
 490         /* WAL_SETTINGS */
 491         gettext_noop("Write-Ahead Log / Settings"),
 492         /* WAL_CHECKPOINTS */
 493         gettext_noop("Write-Ahead Log / Checkpoints"),
 494         /* QUERY_TUNING */
 495         gettext_noop("Query Tuning"),
 496         /* QUERY_TUNING_METHOD */
 497         gettext_noop("Query Tuning / Planner Method Configuration"),
 498         /* QUERY_TUNING_COST */
 499         gettext_noop("Query Tuning / Planner Cost Constants"),
 500         /* QUERY_TUNING_GEQO */
 501         gettext_noop("Query Tuning / Genetic Query Optimizer"),
 502         /* QUERY_TUNING_OTHER */
 503         gettext_noop("Query Tuning / Other Planner Options"),
 504         /* LOGGING */
 505         gettext_noop("Reporting and Logging"),
 506         /* LOGGING_WHERE */
 507         gettext_noop("Reporting and Logging / Where to Log"),
 508         /* LOGGING_WHEN */
 509         gettext_noop("Reporting and Logging / When to Log"),
 510         /* LOGGING_WHAT */
 511         gettext_noop("Reporting and Logging / What to Log"),
 512         /* STATS */
 513         gettext_noop("Statistics"),
 514         /* STATS_MONITORING */
 515         gettext_noop("Statistics / Monitoring"),
 516         /* STATS_COLLECTOR */
 517         gettext_noop("Statistics / Query and Index Statistics Collector"),
 518         /* AUTOVACUUM */
 519         gettext_noop("Autovacuum"),
 520         /* CLIENT_CONN */
 521         gettext_noop("Client Connection Defaults"),
 522         /* CLIENT_CONN_STATEMENT */
 523         gettext_noop("Client Connection Defaults / Statement Behavior"),
 524         /* CLIENT_CONN_LOCALE */
 525         gettext_noop("Client Connection Defaults / Locale and Formatting"),
 526         /* CLIENT_CONN_OTHER */
 527         gettext_noop("Client Connection Defaults / Other Defaults"),
 528         /* LOCK_MANAGEMENT */
 529         gettext_noop("Lock Management"),
 530         /* COMPAT_OPTIONS */
 531         gettext_noop("Version and Platform Compatibility"),
 532         /* COMPAT_OPTIONS_PREVIOUS */
 533         gettext_noop("Version and Platform Compatibility / Previous PostgreSQL Versions"),
 534         /* COMPAT_OPTIONS_CLIENT */
 535         gettext_noop("Version and Platform Compatibility / Other Platforms and Clients"),
 536         /* PRESET_OPTIONS */
 537         gettext_noop("Preset Options"),
 538         /* CUSTOM_OPTIONS */
 539         gettext_noop("Customized Options"),
 540         /* DEVELOPER_OPTIONS */
 541         gettext_noop("Developer Options"),
 542         /* help_config wants this array to be null-terminated */
 543         NULL
 544 };
 545
 546 /*
 547  * Displayable names for GUC variable types (enum config_type)
 548  *
 549  * Note: these strings are deliberately not localized.
 550  */
 551 const char *const config_type_names[] =
 552 {
 553          /* PGC_BOOL */ "bool",
 554          /* PGC_INT */ "integer",
 555          /* PGC_REAL */ "real",
 556          /* PGC_STRING */ "string",
 557          /* PGC_ENUM */ "enum"
 558 };
 559
 560
 561 /*
 562  * Contents of GUC tables
 563  *
 564  * See src/backend/utils/misc/README for design notes.
 565  *
 566  * TO ADD AN OPTION:
 567  *
 568  * 1. Declare a global variable of type bool, int, double, or char*
 569  *        and make use of it.
 570  *
 571  * 2. Decide at what times it's safe to set the option. See guc.h for
 572  *        details.
 573  *
 574  * 3. Decide on a name, a default value, upper and lower bounds (if
 575  *        applicable), etc.
 576  *
 577  * 4. Add a record below.
 578  *
 579  * 5. Add it to src/backend/utils/misc/postgresql.conf.sample, if
 580  *        appropriate.
 581  *
 582  * 6. Don't forget to document the option (at least in config.sgml).
 583  *
 584  * 7. If it's a new GUC_LIST option you must edit pg_dumpall.c to ensure
 585  *        it is not single quoted at dump time.
 586  */
 587
 588
 589 /******** option records follow ********/
 590
 591 static struct config_bool ConfigureNamesBool[] =
 592 {
 593         {
 594                 {"enable_seqscan", PGC_USERSET, QUERY_TUNING_METHOD,
 595                         gettext_noop("Enables the planner's use of sequential-scan plans."),
 596                         NULL
 597                 },
 598                 &enable_seqscan,
 599                 true, NULL, NULL
 600         },
 601         {
 602                 {"enable_indexscan", PGC_USERSET, QUERY_TUNING_METHOD,
 603                         gettext_noop("Enables the planner's use of index-scan plans."),
 604                         NULL
 605                 },
 606                 &enable_indexscan,
 607                 true, NULL, NULL
 608         },
 609         {
 610                 {"enable_bitmapscan", PGC_USERSET, QUERY_TUNING_METHOD,
 611                         gettext_noop("Enables the planner's use of bitmap-scan plans."),
 612                         NULL
 613                 },
 614                 &enable_bitmapscan,
 615                 true, NULL, NULL
 616         },
 617         {
 618                 {"enable_tidscan", PGC_USERSET, QUERY_TUNING_METHOD,
 619                         gettext_noop("Enables the planner's use of TID scan plans."),
 620                         NULL
 621                 },
 622                 &enable_tidscan,
 623                 true, NULL, NULL
 624         },
 625         {
 626                 {"enable_sort", PGC_USERSET, QUERY_TUNING_METHOD,
 627                         gettext_noop("Enables the planner's use of explicit sort steps."),
 628                         NULL
 629                 },
 630                 &enable_sort,
 631                 true, NULL, NULL
 632         },
 633         {
 634                 {"enable_hashagg", PGC_USERSET, QUERY_TUNING_METHOD,
 635                         gettext_noop("Enables the planner's use of hashed aggregation plans."),
 636                         NULL
 637                 },
 638                 &enable_hashagg,
 639                 true, NULL, NULL
 640         },
 641         {
 642                 {"enable_nestloop", PGC_USERSET, QUERY_TUNING_METHOD,
 643                         gettext_noop("Enables the planner's use of nested-loop join plans."),
 644                         NULL
 645                 },
 646                 &enable_nestloop,
 647                 true, NULL, NULL
 648         },
 649         {
 650                 {"enable_mergejoin", PGC_USERSET, QUERY_TUNING_METHOD,
 651                         gettext_noop("Enables the planner's use of merge join plans."),
 652                         NULL
 653                 },
 654                 &enable_mergejoin,
 655                 true, NULL, NULL
 656         },
 657         {
 658                 {"enable_hashjoin", PGC_USERSET, QUERY_TUNING_METHOD,
 659                         gettext_noop("Enables the planner's use of hash join plans."),
 660                         NULL
 661                 },
 662                 &enable_hashjoin,
 663                 true, NULL, NULL
 664         },
 665         {
 666                 {"geqo", PGC_USERSET, QUERY_TUNING_GEQO,
 667                         gettext_noop("Enables genetic query optimization."),
 668                         gettext_noop("This algorithm attempts to do planning without "
 669                                                  "exhaustive searching.")
 670                 },
 671                 &enable_geqo,
 672                 true, NULL, NULL
 673         },
 674         {
 675                 /* Not for general use --- used by SET SESSION AUTHORIZATION */
 676                 {"is_superuser", PGC_INTERNAL, UNGROUPED,
 677                         gettext_noop("Shows whether the current user is a superuser."),
 678                         NULL,
 679                         GUC_REPORT | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
 680                 },
 681                 &session_auth_is_superuser,
 682                 false, NULL, NULL
 683         },
 684         {
 685                 {"ssl", PGC_POSTMASTER, CONN_AUTH_SECURITY,
 686                         gettext_noop("Enables SSL connections."),
 687                         NULL
 688                 },
 689                 &EnableSSL,
 690                 false, assign_ssl, NULL
 691         },
 692         {
 693                 {"fsync", PGC_SIGHUP, WAL_SETTINGS,
 694                         gettext_noop("Forces synchronization of updates to disk."),
 695                         gettext_noop("The server will use the fsync() system call in several places to make "
 696                         "sure that updates are physically written to disk. This insures "
 697                                                  "that a database cluster will recover to a consistent state after "
 698                                                  "an operating system or hardware crash.")
 699                 },
 700                 &enableFsync,
 701                 true, NULL, NULL
 702         },
 703         {
 704                 {"synchronous_commit", PGC_USERSET, WAL_SETTINGS,
 705                         gettext_noop("Sets immediate fsync at commit."),
 706                         NULL
 707                 },
 708                 &XactSyncCommit,
 709                 true, NULL, NULL
 710         },
 711         {
 712                 {"zero_damaged_pages", PGC_SUSET, DEVELOPER_OPTIONS,
 713                         gettext_noop("Continues processing past damaged page headers."),
 714                         gettext_noop("Detection of a damaged page header normally causes PostgreSQL to "
 715                                 "report an error, aborting the current transaction. Setting "
 716                                                  "zero_damaged_pages to true causes the system to instead report a "
 717                                                  "warning, zero out the damaged page, and continue processing. This "
 718                                                  "behavior will destroy data, namely all the rows on the damaged page."),
 719                         GUC_NOT_IN_SAMPLE
 720                 },
 721                 &zero_damaged_pages,
 722                 false, NULL, NULL
 723         },
 724         {
 725                 {"full_page_writes", PGC_SIGHUP, WAL_SETTINGS,
 726                         gettext_noop("Writes full pages to WAL when first modified after a checkpoint."),
 727                         gettext_noop("A page write in process during an operating system crash might be "
 728                                                  "only partially written to disk.  During recovery, the row changes "
 729                           "stored in WAL are not enough to recover.  This option writes "
 730                                                  "pages when first modified after a checkpoint to WAL so full recovery "
 731                                                  "is possible.")
 732                 },
 733                 &fullPageWrites,
 734                 true, NULL, NULL
 735         },
 736         {
 737                 {"silent_mode", PGC_POSTMASTER, LOGGING_WHERE,
 738                         gettext_noop("Runs the server silently."),
 739                         gettext_noop("If this parameter is set, the server will automatically run in the "
 740                                  "background and any controlling terminals are dissociated.")
 741                 },
 742                 &SilentMode,
 743                 false, NULL, NULL
 744         },
 745         {
 746                 {"log_checkpoints", PGC_SIGHUP, LOGGING_WHAT,
 747                         gettext_noop("Logs each checkpoint."),
 748                         NULL
 749                 },
 750                 &log_checkpoints,
 751                 false, NULL, NULL
 752         },
 753         {
 754                 {"log_connections", PGC_BACKEND, LOGGING_WHAT,
 755                         gettext_noop("Logs each successful connection."),
 756                         NULL
 757                 },
 758                 &Log_connections,
 759                 false, NULL, NULL
 760         },
 761         {
 762                 {"log_disconnections", PGC_BACKEND, LOGGING_WHAT,
 763                         gettext_noop("Logs end of a session, including duration."),
 764                         NULL
 765                 },
 766                 &Log_disconnections,
 767                 false, NULL, NULL
 768         },
 769         {
 770                 {"debug_assertions", PGC_USERSET, DEVELOPER_OPTIONS,
 771                         gettext_noop("Turns on various assertion checks."),
 772                         gettext_noop("This is a debugging aid."),
 773                         GUC_NOT_IN_SAMPLE
 774                 },
 775                 &assert_enabled,
 776 #ifdef USE_ASSERT_CHECKING
 777                 true,
 778 #else
 779                 false,
 780 #endif
 781                 assign_debug_assertions, NULL
 782         },
 783         {
 784                 /* currently undocumented, so don't show in SHOW ALL */
 785                 {"exit_on_error", PGC_USERSET, UNGROUPED,
 786                         gettext_noop("No description available."),
 787                         NULL,
 788                         GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE
 789                 },
 790                 &ExitOnAnyError,
 791                 false, NULL, NULL
 792         },
 793         {
 794                 {"log_duration", PGC_SUSET, LOGGING_WHAT,
 795                         gettext_noop("Logs the duration of each completed SQL statement."),
 796                         NULL
 797                 },
 798                 &log_duration,
 799                 false, NULL, NULL
 800         },
 801         {
 802                 {"debug_print_parse", PGC_USERSET, LOGGING_WHAT,
 803                         gettext_noop("Logs each query's parse tree."),
 804                         NULL
 805                 },
 806                 &Debug_print_parse,
 807                 false, NULL, NULL
 808         },
 809         {
 810                 {"debug_print_rewritten", PGC_USERSET, LOGGING_WHAT,
 811                         gettext_noop("Logs each query's rewritten parse tree."),
 812                         NULL
 813                 },
 814                 &Debug_print_rewritten,
 815                 false, NULL, NULL
 816         },
 817         {
 818                 {"debug_print_plan", PGC_USERSET, LOGGING_WHAT,
 819                         gettext_noop("Logs each query's execution plan."),
 820                         NULL
 821                 },
 822                 &Debug_print_plan,
 823                 false, NULL, NULL
 824         },
 825         {
 826                 {"debug_pretty_print", PGC_USERSET, LOGGING_WHAT,
 827                         gettext_noop("Indents parse and plan tree displays."),
 828                         NULL
 829                 },
 830                 &Debug_pretty_print,
 831                 true, NULL, NULL
 832         },
 833         {
 834                 {"log_parser_stats", PGC_SUSET, STATS_MONITORING,
 835                         gettext_noop("Writes parser performance statistics to the server log."),
 836                         NULL
 837                 },
 838                 &log_parser_stats,
 839                 false, assign_stage_log_stats, NULL
 840         },
 841         {
 842                 {"log_planner_stats", PGC_SUSET, STATS_MONITORING,
 843                         gettext_noop("Writes planner performance statistics to the server log."),
 844                         NULL
 845                 },
 846                 &log_planner_stats,
 847                 false, assign_stage_log_stats, NULL
 848         },
 849         {
 850                 {"log_executor_stats", PGC_SUSET, STATS_MONITORING,
 851                         gettext_noop("Writes executor performance statistics to the server log."),
 852                         NULL
 853                 },
 854                 &log_executor_stats,
 855                 false, assign_stage_log_stats, NULL
 856         },
 857         {
 858                 {"log_statement_stats", PGC_SUSET, STATS_MONITORING,
 859                         gettext_noop("Writes cumulative performance statistics to the server log."),
 860                         NULL
 861                 },
 862                 &log_statement_stats,
 863                 false, assign_log_stats, NULL
 864         },
 865 #ifdef BTREE_BUILD_STATS
 866         {
 867                 {"log_btree_build_stats", PGC_SUSET, DEVELOPER_OPTIONS,
 868                         gettext_noop("No description available."),
 869                         NULL,
 870                         GUC_NOT_IN_SAMPLE
 871                 },
 872                 &log_btree_build_stats,
 873                 false, NULL, NULL
 874         },
 875 #endif
 876
 877         {
 878                 {"track_activities", PGC_SUSET, STATS_COLLECTOR,
 879                         gettext_noop("Collects information about executing commands."),
 880                         gettext_noop("Enables the collection of information on the currently "
 881                                                  "executing command of each session, along with "
 882                                                  "the time at which that command began execution.")
 883                 },
 884                 &pgstat_track_activities,
 885                 true, NULL, NULL
 886         },
 887         {
 888                 {"track_counts", PGC_SUSET, STATS_COLLECTOR,
 889                         gettext_noop("Collects statistics on database activity."),
 890                         NULL
 891                 },
 892                 &pgstat_track_counts,
 893                 true, NULL, NULL
 894         },
 895
 896         {
 897                 {"update_process_title", PGC_SUSET, STATS_COLLECTOR,
 898                         gettext_noop("Updates the process title to show the active SQL command."),
 899                         gettext_noop("Enables updating of the process title every time a new SQL command is received by the server.")
 900                 },
 901                 &update_process_title,
 902                 true, NULL, NULL
 903         },
 904
 905         {
 906                 {"autovacuum", PGC_SIGHUP, AUTOVACUUM,
 907                         gettext_noop("Starts the autovacuum subprocess."),
 908                         NULL
 909                 },
 910                 &autovacuum_start_daemon,
 911                 true, NULL, NULL
 912         },
 913
 914         {
 915                 {"trace_notify", PGC_USERSET, DEVELOPER_OPTIONS,
 916                         gettext_noop("Generates debugging output for LISTEN and NOTIFY."),
 917                         NULL,
 918                         GUC_NOT_IN_SAMPLE
 919                 },
 920                 &Trace_notify,
 921                 false, NULL, NULL
 922         },
 923
 924 #ifdef LOCK_DEBUG
 925         {
 926                 {"trace_locks", PGC_SUSET, DEVELOPER_OPTIONS,
 927                         gettext_noop("No description available."),
 928                         NULL,
 929                         GUC_NOT_IN_SAMPLE
 930                 },
 931                 &Trace_locks,
 932                 false, NULL, NULL
 933         },
 934         {
 935                 {"trace_userlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 936                         gettext_noop("No description available."),
 937                         NULL,
 938                         GUC_NOT_IN_SAMPLE
 939                 },
 940                 &Trace_userlocks,
 941                 false, NULL, NULL
 942         },
 943         {
 944                 {"trace_lwlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 945                         gettext_noop("No description available."),
 946                         NULL,
 947                         GUC_NOT_IN_SAMPLE
 948                 },
 949                 &Trace_lwlocks,
 950                 false, NULL, NULL
 951         },
 952         {
 953                 {"debug_deadlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 954                         gettext_noop("No description available."),
 955                         NULL,
 956                         GUC_NOT_IN_SAMPLE
 957                 },
 958                 &Debug_deadlocks,
 959                 false, NULL, NULL
 960         },
 961 #endif
 962
 963         {
 964                 {"log_lock_waits", PGC_SUSET, LOGGING_WHAT,
 965                         gettext_noop("Logs long lock waits."),
 966                         NULL
 967                 },
 968                 &log_lock_waits,
 969                 false, NULL, NULL
 970         },
 971
 972         {
 973                 {"log_hostname", PGC_SIGHUP, LOGGING_WHAT,
 974                         gettext_noop("Logs the host name in the connection logs."),
 975                         gettext_noop("By default, connection logs only show the IP address "
 976                                                  "of the connecting host. If you want them to show the host name you "
 977                           "can turn this on, but depending on your host name resolution "
 978                            "setup it might impose a non-negligible performance penalty.")
 979                 },
 980                 &log_hostname,
 981                 false, NULL, NULL
 982         },
 983         {
 984                 {"sql_inheritance", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
 985                         gettext_noop("Causes subtables to be included by default in various commands."),
 986                         NULL
 987                 },
 988                 &SQL_inheritance,
 989                 true, NULL, NULL
 990         },
 991         {
 992                 {"password_encryption", PGC_USERSET, CONN_AUTH_SECURITY,
 993                         gettext_noop("Encrypt passwords."),
 994                         gettext_noop("When a password is specified in CREATE USER or "
 995                            "ALTER USER without writing either ENCRYPTED or UNENCRYPTED, "
 996                                                  "this parameter determines whether the password is to be encrypted.")
 997                 },
 998                 &Password_encryption,
 999                 true, NULL, NULL
1000         },
1001         {
1002                 {"transform_null_equals", PGC_USERSET, COMPAT_OPTIONS_CLIENT,
1003                         gettext_noop("Treats \"expr=NULL\" as \"expr IS NULL\"."),
1004                         gettext_noop("When turned on, expressions of the form expr = NULL "
1005                            "(or NULL = expr) are treated as expr IS NULL, that is, they "
1006                                 "return true if expr evaluates to the null value, and false "
1007                            "otherwise. The correct behavior of expr = NULL is to always "
1008                                                  "return null (unknown).")
1009                 },
1010                 &Transform_null_equals,
1011                 false, NULL, NULL
1012         },
1013         {
1014                 {"db_user_namespace", PGC_SIGHUP, CONN_AUTH_SECURITY,
1015                         gettext_noop("Enables per-database user names."),
1016                         NULL
1017                 },
1018                 &Db_user_namespace,
1019                 false, NULL, NULL
1020         },
1021         {
1022                 /* only here for backwards compatibility */
1023                 {"autocommit", PGC_USERSET, CLIENT_CONN_STATEMENT,
1024                         gettext_noop("This parameter doesn't do anything."),
1025                         gettext_noop("It's just here so that we won't choke on SET AUTOCOMMIT TO ON from 7.3-vintage clients."),
1026                         GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE
1027                 },
1028                 &phony_autocommit,
1029                 true, assign_phony_autocommit, NULL
1030         },
1031         {
1032                 {"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
1033                         gettext_noop("Sets the default read-only status of new transactions."),
1034                         NULL
1035                 },
1036                 &DefaultXactReadOnly,
1037                 false, NULL, NULL
1038         },
1039         {
1040                 {"transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
1041                         gettext_noop("Sets the current transaction's read-only status."),
1042                         NULL,
1043                         GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1044                 },
1045                 &XactReadOnly,
1046                 false, assign_transaction_read_only, NULL
1047         },
1048         {
1049                 {"add_missing_from", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1050                         gettext_noop("Automatically adds missing table references to FROM clauses."),
1051                         NULL
1052                 },
1053                 &add_missing_from,
1054                 false, NULL, NULL
1055         },
1056         {
1057                 {"check_function_bodies", PGC_USERSET, CLIENT_CONN_STATEMENT,
1058                         gettext_noop("Check function bodies during CREATE FUNCTION."),
1059                         NULL
1060                 },
1061                 &check_function_bodies,
1062                 true, NULL, NULL
1063         },
1064         {
1065                 {"array_nulls", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1066                         gettext_noop("Enable input of NULL elements in arrays."),
1067                         gettext_noop("When turned on, unquoted NULL in an array input "
1068                                                  "value means a null value; "
1069                                                  "otherwise it is taken literally.")
1070                 },
1071                 &Array_nulls,
1072                 true, NULL, NULL
1073         },
1074         {
1075                 {"default_with_oids", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1076                         gettext_noop("Create new tables with OIDs by default."),
1077                         NULL
1078                 },
1079                 &default_with_oids,
1080                 false, NULL, NULL
1081         },
1082         {
1083                 {"logging_collector", PGC_POSTMASTER, LOGGING_WHERE,
1084                         gettext_noop("Start a subprocess to capture stderr output and/or csvlogs into log files."),
1085                         NULL
1086                 },
1087                 &Logging_collector,
1088                 false, NULL, NULL
1089         },
1090         {
1091                 {"log_truncate_on_rotation", PGC_SIGHUP, LOGGING_WHERE,
1092                         gettext_noop("Truncate existing log files of same name during log rotation."),
1093                         NULL
1094                 },
1095                 &Log_truncate_on_rotation,
1096                 false, NULL, NULL
1097         },
1098
1099 #ifdef TRACE_SORT
1100         {
1101                 {"trace_sort", PGC_USERSET, DEVELOPER_OPTIONS,
1102                         gettext_noop("Emit information about resource usage in sorting."),
1103                         NULL,
1104                         GUC_NOT_IN_SAMPLE
1105                 },
1106                 &trace_sort,
1107                 false, NULL, NULL
1108         },
1109 #endif
1110
1111 #ifdef TRACE_SYNCSCAN
1112         /* this is undocumented because not exposed in a standard build */
1113         {
1114                 {"trace_syncscan", PGC_USERSET, DEVELOPER_OPTIONS,
1115                         gettext_noop("Generate debugging output for synchronized scanning."),
1116                         NULL,
1117                         GUC_NOT_IN_SAMPLE
1118                 },
1119                 &trace_syncscan,
1120                 false, NULL, NULL
1121         },
1122 #endif
1123
1124 #ifdef DEBUG_BOUNDED_SORT
1125         /* this is undocumented because not exposed in a standard build */
1126         {
1127                 {
1128                         "optimize_bounded_sort", PGC_USERSET, QUERY_TUNING_METHOD,
1129                         gettext_noop("Enable bounded sorting using heap sort."),
1130                         NULL,
1131                         GUC_NOT_IN_SAMPLE
1132                 },
1133                 &optimize_bounded_sort,
1134                 true, NULL, NULL
1135         },
1136 #endif
1137
1138 #ifdef WAL_DEBUG
1139         {
1140                 {"wal_debug", PGC_SUSET, DEVELOPER_OPTIONS,
1141                         gettext_noop("Emit WAL-related debugging output."),
1142                         NULL,
1143                         GUC_NOT_IN_SAMPLE
1144                 },
1145                 &XLOG_DEBUG,
1146                 false, NULL, NULL
1147         },
1148 #endif
1149
1150         {
1151                 {"integer_datetimes", PGC_INTERNAL, PRESET_OPTIONS,
1152                         gettext_noop("Datetimes are integer based."),
1153                         NULL,
1154                         GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1155                 },
1156                 &integer_datetimes,
1157 #ifdef HAVE_INT64_TIMESTAMP
1158                 true, NULL, NULL
1159 #else
1160                 false, NULL, NULL
1161 #endif
1162         },
1163
1164         {
1165                 {"krb_caseins_users", PGC_SIGHUP, CONN_AUTH_SECURITY,
1166                         gettext_noop("Sets whether Kerberos and GSSAPI user names should be treated as case-insensitive."),
1167                         NULL
1168                 },
1169                 &pg_krb_caseins_users,
1170                 false, NULL, NULL
1171         },
1172
1173         {
1174                 {"escape_string_warning", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1175                         gettext_noop("Warn about backslash escapes in ordinary string literals."),
1176                         NULL
1177                 },
1178                 &escape_string_warning,
1179                 true, NULL, NULL
1180         },
1181
1182         {
1183                 {"standard_conforming_strings", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1184                         gettext_noop("Causes '...' strings to treat backslashes literally."),
1185                         NULL,
1186                         GUC_REPORT
1187                 },
1188                 &standard_conforming_strings,
1189                 false, NULL, NULL
1190         },
1191
1192         {
1193                 {"synchronize_seqscans", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1194                         gettext_noop("Enable synchronized sequential scans."),
1195                         NULL
1196                 },
1197                 &synchronize_seqscans,
1198                 true, NULL, NULL
1199         },
1200
1201         {
1202                 {"archive_mode", PGC_POSTMASTER, WAL_SETTINGS,
1203                         gettext_noop("Allows archiving of WAL files using archive_command."),
1204                         NULL
1205                 },
1206                 &XLogArchiveMode,
1207                 false, NULL, NULL
1208         },
1209
1210         {
1211                 {"allow_system_table_mods", PGC_POSTMASTER, DEVELOPER_OPTIONS,
1212                         gettext_noop("Allows modifications of the structure of system tables."),
1213                         NULL,
1214                         GUC_NOT_IN_SAMPLE
1215                 },
1216                 &allowSystemTableMods,
1217                 false, NULL, NULL
1218         },
1219
1220         {
1221                 {"ignore_system_indexes", PGC_BACKEND, DEVELOPER_OPTIONS,
1222                         gettext_noop("Disables reading from system indexes."),
1223                         gettext_noop("It does not prevent updating the indexes, so it is safe "
1224                                                  "to use.  The worst consequence is slowness."),
1225                         GUC_NOT_IN_SAMPLE
1226                 },
1227                 &IgnoreSystemIndexes,
1228                 false, NULL, NULL
1229         },
1230
1231         /* End-of-list marker */
1232         {
1233                 {NULL, 0, 0, NULL, NULL}, NULL, false, NULL, NULL
1234         }
1235 };
1236
1237
1238 static struct config_int ConfigureNamesInt[] =
1239 {
1240         {
1241                 {"archive_timeout", PGC_SIGHUP, WAL_SETTINGS,
1242                         gettext_noop("Forces a switch to the next xlog file if a "
1243                                                  "new file has not been started within N seconds."),
1244                         NULL,
1245                         GUC_UNIT_S
1246                 },
1247                 &XLogArchiveTimeout,
1248                 0, 0, INT_MAX, NULL, NULL
1249         },
1250         {
1251                 {"post_auth_delay", PGC_BACKEND, DEVELOPER_OPTIONS,
1252                         gettext_noop("Waits N seconds on connection startup after authentication."),
1253                         gettext_noop("This allows attaching a debugger to the process."),
1254                         GUC_NOT_IN_SAMPLE | GUC_UNIT_S
1255                 },
1256                 &PostAuthDelay,
1257                 0, 0, INT_MAX, NULL, NULL
1258         },
1259         {
1260                 {"default_statistics_target", PGC_USERSET, QUERY_TUNING_OTHER,
1261                         gettext_noop("Sets the default statistics target."),
1262                         gettext_noop("This applies to table columns that have not had a "
1263                                 "column-specific target set via ALTER TABLE SET STATISTICS.")
1264                 },
1265                 &default_statistics_target,
1266                 100, 1, 10000, NULL, NULL
1267         },
1268         {
1269                 {"from_collapse_limit", PGC_USERSET, QUERY_TUNING_OTHER,
1270                         gettext_noop("Sets the FROM-list size beyond which subqueries "
1271                                                  "are not collapsed."),
1272                         gettext_noop("The planner will merge subqueries into upper "
1273                                 "queries if the resulting FROM list would have no more than "
1274                                                  "this many items.")
1275                 },
1276                 &from_collapse_limit,
1277                 8, 1, INT_MAX, NULL, NULL
1278         },
1279         {
1280                 {"join_collapse_limit", PGC_USERSET, QUERY_TUNING_OTHER,
1281                         gettext_noop("Sets the FROM-list size beyond which JOIN "
1282                                                  "constructs are not flattened."),
1283                         gettext_noop("The planner will flatten explicit JOIN "
1284                                                  "constructs into lists of FROM items whenever a "
1285                                                  "list of no more than this many items would result.")
1286                 },
1287                 &join_collapse_limit,
1288                 8, 1, INT_MAX, NULL, NULL
1289         },
1290         {
1291                 {"geqo_threshold", PGC_USERSET, QUERY_TUNING_GEQO,
1292                         gettext_noop("Sets the threshold of FROM items beyond which GEQO is used."),
1293                         NULL
1294                 },
1295                 &geqo_threshold,
1296                 12, 2, INT_MAX, NULL, NULL
1297         },
1298         {
1299                 {"geqo_effort", PGC_USERSET, QUERY_TUNING_GEQO,
1300                         gettext_noop("GEQO: effort is used to set the default for other GEQO parameters."),
1301                         NULL
1302                 },
1303                 &Geqo_effort,
1304                 DEFAULT_GEQO_EFFORT, MIN_GEQO_EFFORT, MAX_GEQO_EFFORT, NULL, NULL
1305         },
1306         {
1307                 {"geqo_pool_size", PGC_USERSET, QUERY_TUNING_GEQO,
1308                         gettext_noop("GEQO: number of individuals in the population."),
1309                         gettext_noop("Zero selects a suitable default value.")
1310                 },
1311                 &Geqo_pool_size,
1312                 0, 0, INT_MAX, NULL, NULL
1313         },
1314         {
1315                 {"geqo_generations", PGC_USERSET, QUERY_TUNING_GEQO,
1316                         gettext_noop("GEQO: number of iterations of the algorithm."),
1317                         gettext_noop("Zero selects a suitable default value.")
1318                 },
1319                 &Geqo_generations,
1320                 0, 0, INT_MAX, NULL, NULL
1321         },
1322
1323         {
1324                 /* This is PGC_SIGHUP so all backends have the same value. */
1325                 {"deadlock_timeout", PGC_SIGHUP, LOCK_MANAGEMENT,
1326                         gettext_noop("Sets the time to wait on a lock before checking for deadlock."),
1327                         NULL,
1328                         GUC_UNIT_MS
1329                 },
1330                 &DeadlockTimeout,
1331                 1000, 1, INT_MAX / 1000, NULL, NULL
1332         },
1333
1334         /*
1335          * Note: MaxBackends is limited to INT_MAX/4 because some places compute
1336          * 4*MaxBackends without any overflow check.  This check is made in
1337          * assign_maxconnections, since MaxBackends is computed as MaxConnections
1338          * plus autovacuum_max_workers plus one (for the autovacuum launcher).
1339          *
1340          * Likewise we have to limit NBuffers to INT_MAX/2.
1341          */
1342         {
1343                 {"max_connections", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1344                         gettext_noop("Sets the maximum number of concurrent connections."),
1345                         NULL
1346                 },
1347                 &MaxConnections,
1348                 100, 1, INT_MAX / 4, assign_maxconnections, NULL
1349         },
1350
1351         {
1352                 {"superuser_reserved_connections", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1353                         gettext_noop("Sets the number of connection slots reserved for superusers."),
1354                         NULL
1355                 },
1356                 &ReservedBackends,
1357                 3, 0, INT_MAX / 4, NULL, NULL
1358         },
1359
1360         {
1361                 {"shared_buffers", PGC_POSTMASTER, RESOURCES_MEM,
1362                         gettext_noop("Sets the number of shared memory buffers used by the server."),
1363                         NULL,
1364                         GUC_UNIT_BLOCKS
1365                 },
1366                 &NBuffers,
1367                 1024, 16, INT_MAX / 2, NULL, NULL
1368         },
1369
1370         {
1371                 {"temp_buffers", PGC_USERSET, RESOURCES_MEM,
1372                         gettext_noop("Sets the maximum number of temporary buffers used by each session."),
1373                         NULL,
1374                         GUC_UNIT_BLOCKS
1375                 },
1376                 &num_temp_buffers,
1377                 1024, 100, INT_MAX / 2, NULL, show_num_temp_buffers
1378         },
1379
1380         {
1381                 {"port", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1382                         gettext_noop("Sets the TCP port the server listens on."),
1383                         NULL
1384                 },
1385                 &PostPortNumber,
1386                 DEF_PGPORT, 1, 65535, NULL, NULL
1387         },
1388
1389         {
1390                 {"unix_socket_permissions", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1391                         gettext_noop("Sets the access permissions of the Unix-domain socket."),
1392                         gettext_noop("Unix-domain sockets use the usual Unix file system "
1393                                                  "permission set. The parameter value is expected to be a numeric mode "
1394                                                  "specification in the form accepted by the chmod and umask system "
1395                                                  "calls. (To use the customary octal format the number must start with "
1396                                                  "a 0 (zero).)")
1397                 },
1398                 &Unix_socket_permissions,
1399                 0777, 0000, 0777, NULL, NULL
1400         },
1401
1402         {
1403                 {"work_mem", PGC_USERSET, RESOURCES_MEM,
1404                         gettext_noop("Sets the maximum memory to be used for query workspaces."),
1405                         gettext_noop("This much memory can be used by each internal "
1406                                                  "sort operation and hash table before switching to "
1407                                                  "temporary disk files."),
1408                         GUC_UNIT_KB
1409                 },
1410                 &work_mem,
1411                 1024, 64, MAX_KILOBYTES, NULL, NULL
1412         },
1413
1414         {
1415                 {"maintenance_work_mem", PGC_USERSET, RESOURCES_MEM,
1416                         gettext_noop("Sets the maximum memory to be used for maintenance operations."),
1417                         gettext_noop("This includes operations such as VACUUM and CREATE INDEX."),
1418                         GUC_UNIT_KB
1419                 },
1420                 &maintenance_work_mem,
1421                 16384, 1024, MAX_KILOBYTES, NULL, NULL
1422         },
1423
1424         {
1425                 {"max_stack_depth", PGC_SUSET, RESOURCES_MEM,
1426                         gettext_noop("Sets the maximum stack depth, in kilobytes."),
1427                         NULL,
1428                         GUC_UNIT_KB
1429                 },
1430                 &max_stack_depth,
1431                 100, 100, MAX_KILOBYTES, assign_max_stack_depth, NULL
1432         },
1433
1434         {
1435                 {"vacuum_cost_page_hit", PGC_USERSET, RESOURCES,
1436                         gettext_noop("Vacuum cost for a page found in the buffer cache."),
1437                         NULL
1438                 },
1439                 &VacuumCostPageHit,
1440                 1, 0, 10000, NULL, NULL
1441         },
1442
1443         {
1444                 {"vacuum_cost_page_miss", PGC_USERSET, RESOURCES,
1445                         gettext_noop("Vacuum cost for a page not found in the buffer cache."),
1446                         NULL
1447                 },
1448                 &VacuumCostPageMiss,
1449                 10, 0, 10000, NULL, NULL
1450         },
1451
1452         {
1453                 {"vacuum_cost_page_dirty", PGC_USERSET, RESOURCES,
1454                         gettext_noop("Vacuum cost for a page dirtied by vacuum."),
1455                         NULL
1456                 },
1457                 &VacuumCostPageDirty,
1458                 20, 0, 10000, NULL, NULL
1459         },
1460
1461         {
1462                 {"vacuum_cost_limit", PGC_USERSET, RESOURCES,
1463                         gettext_noop("Vacuum cost amount available before napping."),
1464                         NULL
1465                 },
1466                 &VacuumCostLimit,
1467                 200, 1, 10000, NULL, NULL
1468         },
1469
1470         {
1471                 {"vacuum_cost_delay", PGC_USERSET, RESOURCES,
1472                         gettext_noop("Vacuum cost delay in milliseconds."),
1473                         NULL,
1474                         GUC_UNIT_MS
1475                 },
1476                 &VacuumCostDelay,
1477                 0, 0, 100, NULL, NULL
1478         },
1479
1480         {
1481                 {"autovacuum_vacuum_cost_delay", PGC_SIGHUP, AUTOVACUUM,
1482                         gettext_noop("Vacuum cost delay in milliseconds, for autovacuum."),
1483                         NULL,
1484                         GUC_UNIT_MS
1485                 },
1486                 &autovacuum_vac_cost_delay,
1487                 20, -1, 100, NULL, NULL
1488         },
1489
1490         {
1491                 {"autovacuum_vacuum_cost_limit", PGC_SIGHUP, AUTOVACUUM,
1492                         gettext_noop("Vacuum cost amount available before napping, for autovacuum."),
1493                         NULL
1494                 },
1495                 &autovacuum_vac_cost_limit,
1496                 -1, -1, 10000, NULL, NULL
1497         },
1498
1499         {
1500                 {"max_files_per_process", PGC_POSTMASTER, RESOURCES_KERNEL,
1501                         gettext_noop("Sets the maximum number of simultaneously open files for each server process."),
1502                         NULL
1503                 },
1504                 &max_files_per_process,
1505                 1000, 25, INT_MAX, NULL, NULL
1506         },
1507
1508         {
1509                 {"max_prepared_transactions", PGC_POSTMASTER, RESOURCES,
1510                         gettext_noop("Sets the maximum number of simultaneously prepared transactions."),
1511                         NULL
1512                 },
1513                 &max_prepared_xacts,
1514                 0, 0, INT_MAX / 4, NULL, NULL
1515         },
1516
1517 #ifdef LOCK_DEBUG
1518         {
1519                 {"trace_lock_oidmin", PGC_SUSET, DEVELOPER_OPTIONS,
1520                         gettext_noop("No description available."),
1521                         NULL,
1522                         GUC_NOT_IN_SAMPLE
1523                 },
1524                 &Trace_lock_oidmin,
1525                 FirstNormalObjectId, 0, INT_MAX, NULL, NULL
1526         },
1527         {
1528                 {"trace_lock_table", PGC_SUSET, DEVELOPER_OPTIONS,
1529                         gettext_noop("No description available."),
1530                         NULL,
1531                         GUC_NOT_IN_SAMPLE
1532                 },
1533                 &Trace_lock_table,
1534                 0, 0, INT_MAX, NULL, NULL
1535         },
1536 #endif
1537
1538         {
1539                 {"statement_timeout", PGC_USERSET, CLIENT_CONN_STATEMENT,
1540                         gettext_noop("Sets the maximum allowed duration of any statement."),
1541                         gettext_noop("A value of 0 turns off the timeout."),
1542                         GUC_UNIT_MS
1543                 },
1544                 &StatementTimeout,
1545                 0, 0, INT_MAX, NULL, NULL
1546         },
1547
1548         {
1549                 {"vacuum_freeze_min_age", PGC_USERSET, CLIENT_CONN_STATEMENT,
1550                         gettext_noop("Minimum age at which VACUUM should freeze a table row."),
1551                         NULL
1552                 },
1553                 &vacuum_freeze_min_age,
1554                 50000000, 0, 1000000000, NULL, NULL
1555         },
1556
1557         {
1558                 {"vacuum_freeze_table_age", PGC_USERSET, CLIENT_CONN_STATEMENT,
1559                         gettext_noop("Age at which VACUUM should scan whole table to freeze tuples."),
1560                         NULL
1561                 },
1562                 &vacuum_freeze_table_age,
1563                 150000000, 0, 2000000000, NULL, NULL
1564         },
1565
1566         {
1567                 {"max_locks_per_transaction", PGC_POSTMASTER, LOCK_MANAGEMENT,
1568                         gettext_noop("Sets the maximum number of locks per transaction."),
1569                         gettext_noop("The shared lock table is sized on the assumption that "
1570                           "at most max_locks_per_transaction * max_connections distinct "
1571                                                  "objects will need to be locked at any one time.")
1572                 },
1573                 &max_locks_per_xact,
1574                 64, 10, INT_MAX, NULL, NULL
1575         },
1576
1577         {
1578                 {"authentication_timeout", PGC_SIGHUP, CONN_AUTH_SECURITY,
1579                         gettext_noop("Sets the maximum allowed time to complete client authentication."),
1580                         NULL,
1581                         GUC_UNIT_S
1582                 },
1583                 &AuthenticationTimeout,
1584                 60, 1, 600, NULL, NULL
1585         },
1586
1587         {
1588                 /* Not for general use */
1589                 {"pre_auth_delay", PGC_SIGHUP, DEVELOPER_OPTIONS,
1590                         gettext_noop("Waits N seconds on connection startup before authentication."),
1591                         gettext_noop("This allows attaching a debugger to the process."),
1592                         GUC_NOT_IN_SAMPLE | GUC_UNIT_S
1593                 },
1594                 &PreAuthDelay,
1595                 0, 0, 60, NULL, NULL
1596         },
1597
1598         {
1599                 {"checkpoint_segments", PGC_SIGHUP, WAL_CHECKPOINTS,
1600                         gettext_noop("Sets the maximum distance in log segments between automatic WAL checkpoints."),
1601                         NULL
1602                 },
1603                 &CheckPointSegments,
1604                 3, 1, INT_MAX, NULL, NULL
1605         },
1606
1607         {
1608                 {"checkpoint_timeout", PGC_SIGHUP, WAL_CHECKPOINTS,
1609                         gettext_noop("Sets the maximum time between automatic WAL checkpoints."),
1610                         NULL,
1611                         GUC_UNIT_S
1612                 },
1613                 &CheckPointTimeout,
1614                 300, 30, 3600, NULL, NULL
1615         },
1616
1617         {
1618                 {"checkpoint_warning", PGC_SIGHUP, WAL_CHECKPOINTS,
1619                         gettext_noop("Enables warnings if checkpoint segments are filled more "
1620                                                  "frequently than this."),
1621                         gettext_noop("Write a message to the server log if checkpoints "
1622                         "caused by the filling of checkpoint segment files happens more "
1623                                                  "frequently than this number of seconds. Zero turns off the warning."),
1624                         GUC_UNIT_S
1625                 },
1626                 &CheckPointWarning,
1627                 30, 0, INT_MAX, NULL, NULL
1628         },
1629
1630         {
1631                 {"wal_buffers", PGC_POSTMASTER, WAL_SETTINGS,
1632                         gettext_noop("Sets the number of disk-page buffers in shared memory for WAL."),
1633                         NULL,
1634                         GUC_UNIT_XBLOCKS
1635                 },
1636                 &XLOGbuffers,
1637                 8, 4, INT_MAX, NULL, NULL
1638         },
1639
1640         {
1641                 {"wal_writer_delay", PGC_SIGHUP, WAL_SETTINGS,
1642                         gettext_noop("WAL writer sleep time between WAL flushes."),
1643                         NULL,
1644                         GUC_UNIT_MS
1645                 },
1646                 &WalWriterDelay,
1647                 200, 1, 10000, NULL, NULL
1648         },
1649
1650         {
1651                 {"commit_delay", PGC_USERSET, WAL_SETTINGS,
1652                         gettext_noop("Sets the delay in microseconds between transaction commit and "
1653                                                  "flushing WAL to disk."),
1654                         NULL
1655                 },
1656                 &CommitDelay,
1657                 0, 0, 100000, NULL, NULL
1658         },
1659
1660         {
1661                 {"commit_siblings", PGC_USERSET, WAL_SETTINGS,
1662                         gettext_noop("Sets the minimum concurrent open transactions before performing "
1663                                                  "commit_delay."),
1664                         NULL
1665                 },
1666                 &CommitSiblings,
1667                 5, 1, 1000, NULL, NULL
1668         },
1669
1670         {
1671                 {"extra_float_digits", PGC_USERSET, CLIENT_CONN_LOCALE,
1672                         gettext_noop("Sets the number of digits displayed for floating-point values."),
1673                         gettext_noop("This affects real, double precision, and geometric data types. "
1674                          "The parameter value is added to the standard number of digits "
1675                                                  "(FLT_DIG or DBL_DIG as appropriate).")
1676                 },
1677                 &extra_float_digits,
1678                 0, -15, 2, NULL, NULL
1679         },
1680
1681         {
1682                 {"log_min_duration_statement", PGC_SUSET, LOGGING_WHEN,
1683                         gettext_noop("Sets the minimum execution time above which "
1684                                                  "statements will be logged."),
1685                         gettext_noop("Zero prints all queries. -1 turns this feature off."),
1686                         GUC_UNIT_MS
1687                 },
1688                 &log_min_duration_statement,
1689                 -1, -1, INT_MAX / 1000, NULL, NULL
1690         },
1691
1692         {
1693                 {"log_autovacuum_min_duration", PGC_SIGHUP, LOGGING_WHAT,
1694                         gettext_noop("Sets the minimum execution time above which "
1695                                                  "autovacuum actions will be logged."),
1696                         gettext_noop("Zero prints all actions. -1 turns autovacuum logging off."),
1697                         GUC_UNIT_MS
1698                 },
1699                 &Log_autovacuum_min_duration,
1700                 -1, -1, INT_MAX / 1000, NULL, NULL
1701         },
1702
1703         {
1704                 {"bgwriter_delay", PGC_SIGHUP, RESOURCES,
1705                         gettext_noop("Background writer sleep time between rounds."),
1706                         NULL,
1707                         GUC_UNIT_MS
1708                 },
1709                 &BgWriterDelay,
1710                 200, 10, 10000, NULL, NULL
1711         },
1712
1713         {
1714                 {"bgwriter_lru_maxpages", PGC_SIGHUP, RESOURCES,
1715                         gettext_noop("Background writer maximum number of LRU pages to flush per round."),
1716                         NULL
1717                 },
1718                 &bgwriter_lru_maxpages,
1719                 100, 0, 1000, NULL, NULL
1720         },
1721
1722         {
1723                 {"effective_io_concurrency",
1724 #ifdef USE_PREFETCH
1725                         PGC_USERSET,
1726 #else
1727                         PGC_INTERNAL,
1728 #endif
1729                         RESOURCES,
1730                         gettext_noop("Number of simultaneous requests that can be handled efficiently by the disk subsystem."),
1731                         gettext_noop("For RAID arrays, this should be approximately the number of drive spindles in the array.")
1732                 },
1733                 &effective_io_concurrency,
1734 #ifdef USE_PREFETCH
1735                 1, 0, 1000,
1736 #else
1737                 0, 0, 0,
1738 #endif
1739                 assign_effective_io_concurrency, NULL
1740         },
1741
1742         {
1743                 {"log_rotation_age", PGC_SIGHUP, LOGGING_WHERE,
1744                         gettext_noop("Automatic log file rotation will occur after N minutes."),
1745                         NULL,
1746                         GUC_UNIT_MIN
1747                 },
1748                 &Log_RotationAge,
1749                 HOURS_PER_DAY * MINS_PER_HOUR, 0, INT_MAX / MINS_PER_HOUR, NULL, NULL
1750         },
1751
1752         {
1753                 {"log_rotation_size", PGC_SIGHUP, LOGGING_WHERE,
1754                         gettext_noop("Automatic log file rotation will occur after N kilobytes."),
1755                         NULL,
1756                         GUC_UNIT_KB
1757                 },
1758                 &Log_RotationSize,
1759                 10 * 1024, 0, INT_MAX / 1024, NULL, NULL
1760         },
1761
1762         {
1763                 {"max_function_args", PGC_INTERNAL, PRESET_OPTIONS,
1764                         gettext_noop("Shows the maximum number of function arguments."),
1765                         NULL,
1766                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1767                 },
1768                 &max_function_args,
1769                 FUNC_MAX_ARGS, FUNC_MAX_ARGS, FUNC_MAX_ARGS, NULL, NULL
1770         },
1771
1772         {
1773                 {"max_index_keys", PGC_INTERNAL, PRESET_OPTIONS,
1774                         gettext_noop("Shows the maximum number of index keys."),
1775                         NULL,
1776                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1777                 },
1778                 &max_index_keys,
1779                 INDEX_MAX_KEYS, INDEX_MAX_KEYS, INDEX_MAX_KEYS, NULL, NULL
1780         },
1781
1782         {
1783                 {"max_identifier_length", PGC_INTERNAL, PRESET_OPTIONS,
1784                         gettext_noop("Shows the maximum identifier length."),
1785                         NULL,
1786                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1787                 },
1788                 &max_identifier_length,
1789                 NAMEDATALEN - 1, NAMEDATALEN - 1, NAMEDATALEN - 1, NULL, NULL
1790         },
1791
1792         {
1793                 {"block_size", PGC_INTERNAL, PRESET_OPTIONS,
1794                         gettext_noop("Shows the size of a disk block."),
1795                         NULL,
1796                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1797                 },
1798                 &block_size,
1799                 BLCKSZ, BLCKSZ, BLCKSZ, NULL, NULL
1800         },
1801
1802         {
1803                 {"segment_size", PGC_INTERNAL, PRESET_OPTIONS,
1804                         gettext_noop("Shows the number of pages per disk file."),
1805                         NULL,
1806                         GUC_UNIT_BLOCKS | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1807                 },
1808                 &segment_size,
1809                 RELSEG_SIZE, RELSEG_SIZE, RELSEG_SIZE, NULL, NULL
1810         },
1811
1812         {
1813                 {"wal_block_size", PGC_INTERNAL, PRESET_OPTIONS,
1814                         gettext_noop("Shows the block size in the write ahead log."),
1815                         NULL,
1816                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1817                 },
1818                 &wal_block_size,
1819                 XLOG_BLCKSZ, XLOG_BLCKSZ, XLOG_BLCKSZ, NULL, NULL
1820         },
1821
1822         {
1823                 {"wal_segment_size", PGC_INTERNAL, PRESET_OPTIONS,
1824                         gettext_noop("Shows the number of pages per write ahead log segment."),
1825                         NULL,
1826                         GUC_UNIT_XBLOCKS | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1827                 },
1828                 &wal_segment_size,
1829                 (XLOG_SEG_SIZE / XLOG_BLCKSZ),
1830                 (XLOG_SEG_SIZE / XLOG_BLCKSZ),
1831                 (XLOG_SEG_SIZE / XLOG_BLCKSZ),
1832                 NULL, NULL
1833         },
1834
1835         {
1836                 {"autovacuum_naptime", PGC_SIGHUP, AUTOVACUUM,
1837                         gettext_noop("Time to sleep between autovacuum runs."),
1838                         NULL,
1839                         GUC_UNIT_S
1840                 },
1841                 &autovacuum_naptime,
1842                 60, 1, INT_MAX / 1000, NULL, NULL
1843         },
1844         {
1845                 {"autovacuum_vacuum_threshold", PGC_SIGHUP, AUTOVACUUM,
1846                         gettext_noop("Minimum number of tuple updates or deletes prior to vacuum."),
1847                         NULL
1848                 },
1849                 &autovacuum_vac_thresh,
1850                 50, 0, INT_MAX, NULL, NULL
1851         },
1852         {
1853                 {"autovacuum_analyze_threshold", PGC_SIGHUP, AUTOVACUUM,
1854                         gettext_noop("Minimum number of tuple inserts, updates or deletes prior to analyze."),
1855                         NULL
1856                 },
1857                 &autovacuum_anl_thresh,
1858                 50, 0, INT_MAX, NULL, NULL
1859         },
1860         {
1861                 /* see varsup.c for why this is PGC_POSTMASTER not PGC_SIGHUP */
1862                 {"autovacuum_freeze_max_age", PGC_POSTMASTER, AUTOVACUUM,
1863                         gettext_noop("Age at which to autovacuum a table to prevent transaction ID wraparound."),
1864                         NULL
1865                 },
1866                 &autovacuum_freeze_max_age,
1867                 /* see pg_resetxlog if you change the upper-limit value */
1868                 200000000, 100000000, 2000000000, NULL, NULL
1869         },
1870         {
1871                 /* see max_connections */
1872                 {"autovacuum_max_workers", PGC_POSTMASTER, AUTOVACUUM,
1873                         gettext_noop("Sets the maximum number of simultaneously running autovacuum worker processes."),
1874                         NULL
1875                 },
1876                 &autovacuum_max_workers,
1877                 3, 1, INT_MAX / 4, assign_autovacuum_max_workers, NULL
1878         },
1879
1880         {
1881                 {"tcp_keepalives_idle", PGC_USERSET, CLIENT_CONN_OTHER,
1882                         gettext_noop("Time between issuing TCP keepalives."),
1883                         gettext_noop("A value of 0 uses the system default."),
1884                         GUC_UNIT_S
1885                 },
1886                 &tcp_keepalives_idle,
1887                 0, 0, INT_MAX, assign_tcp_keepalives_idle, show_tcp_keepalives_idle
1888         },
1889
1890         {
1891                 {"tcp_keepalives_interval", PGC_USERSET, CLIENT_CONN_OTHER,
1892                         gettext_noop("Time between TCP keepalive retransmits."),
1893                         gettext_noop("A value of 0 uses the system default."),
1894                         GUC_UNIT_S
1895                 },
1896                 &tcp_keepalives_interval,
1897                 0, 0, INT_MAX, assign_tcp_keepalives_interval, show_tcp_keepalives_interval
1898         },
1899
1900         {
1901                 {"tcp_keepalives_count", PGC_USERSET, CLIENT_CONN_OTHER,
1902                         gettext_noop("Maximum number of TCP keepalive retransmits."),
1903                         gettext_noop("This controls the number of consecutive keepalive retransmits that can be "
1904                                                  "lost before a connection is considered dead. A value of 0 uses the "
1905                                                  "system default."),
1906                 },
1907                 &tcp_keepalives_count,
1908                 0, 0, INT_MAX, assign_tcp_keepalives_count, show_tcp_keepalives_count
1909         },
1910
1911         {
1912                 {"gin_fuzzy_search_limit", PGC_USERSET, CLIENT_CONN_OTHER,
1913                         gettext_noop("Sets the maximum allowed result for exact search by GIN."),
1914                         NULL,
1915                         0
1916                 },
1917                 &GinFuzzySearchLimit,
1918                 0, 0, INT_MAX, NULL, NULL
1919         },
1920
1921         {
1922                 {"effective_cache_size", PGC_USERSET, QUERY_TUNING_COST,
1923                         gettext_noop("Sets the planner's assumption about the size of the disk cache."),
1924                         gettext_noop("That is, the portion of the kernel's disk cache that "
1925                                                  "will be used for PostgreSQL data files. This is measured in disk "
1926                                                  "pages, which are normally 8 kB each."),
1927                         GUC_UNIT_BLOCKS,
1928                 },
1929                 &effective_cache_size,
1930                 DEFAULT_EFFECTIVE_CACHE_SIZE, 1, INT_MAX, NULL, NULL
1931         },
1932
1933         {
1934                 /* Can't be set in postgresql.conf */
1935                 {"server_version_num", PGC_INTERNAL, PRESET_OPTIONS,
1936                         gettext_noop("Shows the server version as an integer."),
1937                         NULL,
1938                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1939                 },
1940                 &server_version_num,
1941                 PG_VERSION_NUM, PG_VERSION_NUM, PG_VERSION_NUM, NULL, NULL
1942         },
1943
1944         {
1945                 {"log_temp_files", PGC_SUSET, LOGGING_WHAT,
1946                         gettext_noop("Log the use of temporary files larger than this number of kilobytes."),
1947                         gettext_noop("Zero logs all files. The default is -1 (turning this feature off)."),
1948                         GUC_UNIT_KB
1949                 },
1950                 &log_temp_files,
1951                 -1, -1, INT_MAX, NULL, NULL
1952         },
1953
1954         {
1955                 {"track_activity_query_size", PGC_POSTMASTER, RESOURCES_MEM,
1956                         gettext_noop("Sets the size reserved for pg_stat_activity.current_query, in bytes."),
1957                         NULL,
1958                 },
1959                 &pgstat_track_activity_query_size,
1960                 1024, 100, 102400, NULL, NULL
1961         },
1962
1963         /* End-of-list marker */
1964         {
1965                 {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL
1966         }
1967 };
1968
1969
1970 static struct config_real ConfigureNamesReal[] =
1971 {
1972         {
1973                 {"seq_page_cost", PGC_USERSET, QUERY_TUNING_COST,
1974                         gettext_noop("Sets the planner's estimate of the cost of a "
1975                                                  "sequentially fetched disk page."),
1976                         NULL
1977                 },
1978                 &seq_page_cost,
1979                 DEFAULT_SEQ_PAGE_COST, 0, DBL_MAX, NULL, NULL
1980         },
1981         {
1982                 {"random_page_cost", PGC_USERSET, QUERY_TUNING_COST,
1983                         gettext_noop("Sets the planner's estimate of the cost of a "
1984                                                  "nonsequentially fetched disk page."),
1985                         NULL
1986                 },
1987                 &random_page_cost,
1988                 DEFAULT_RANDOM_PAGE_COST, 0, DBL_MAX, NULL, NULL
1989         },
1990         {
1991                 {"cpu_tuple_cost", PGC_USERSET, QUERY_TUNING_COST,
1992                         gettext_noop("Sets the planner's estimate of the cost of "
1993                                                  "processing each tuple (row)."),
1994                         NULL
1995                 },
1996                 &cpu_tuple_cost,
1997                 DEFAULT_CPU_TUPLE_COST, 0, DBL_MAX, NULL, NULL
1998         },
1999         {
2000                 {"cpu_index_tuple_cost", PGC_USERSET, QUERY_TUNING_COST,
2001                         gettext_noop("Sets the planner's estimate of the cost of "
2002                                                  "processing each index entry during an index scan."),
2003                         NULL
2004                 },
2005                 &cpu_index_tuple_cost,
2006                 DEFAULT_CPU_INDEX_TUPLE_COST, 0, DBL_MAX, NULL, NULL
2007         },
2008         {
2009                 {"cpu_operator_cost", PGC_USERSET, QUERY_TUNING_COST,
2010                         gettext_noop("Sets the planner's estimate of the cost of "
2011                                                  "processing each operator or function call."),
2012                         NULL
2013                 },
2014                 &cpu_operator_cost,
2015                 DEFAULT_CPU_OPERATOR_COST, 0, DBL_MAX, NULL, NULL
2016         },
2017
2018         {
2019                 {"cursor_tuple_fraction", PGC_USERSET, QUERY_TUNING_OTHER,
2020                         gettext_noop("Sets the planner's estimate of the fraction of "
2021                                                  "a cursor's rows that will be retrieved."),
2022                         NULL
2023                 },
2024                 &cursor_tuple_fraction,
2025                 DEFAULT_CURSOR_TUPLE_FRACTION, 0.0, 1.0, NULL, NULL
2026         },
2027
2028         {
2029                 {"geqo_selection_bias", PGC_USERSET, QUERY_TUNING_GEQO,
2030                         gettext_noop("GEQO: selective pressure within the population."),
2031                         NULL
2032                 },
2033                 &Geqo_selection_bias,
2034                 DEFAULT_GEQO_SELECTION_BIAS, MIN_GEQO_SELECTION_BIAS,
2035                 MAX_GEQO_SELECTION_BIAS, NULL, NULL
2036         },
2037         {
2038                 {"geqo_seed", PGC_USERSET, QUERY_TUNING_GEQO,
2039                         gettext_noop("GEQO: seed for random path selection."),
2040                         NULL
2041                 },
2042                 &Geqo_seed,
2043                 0.0, 0.0, 1.0, NULL, NULL
2044         },
2045
2046         {
2047                 {"bgwriter_lru_multiplier", PGC_SIGHUP, RESOURCES,
2048                         gettext_noop("Multiple of the average buffer usage to free per round."),
2049                         NULL
2050                 },
2051                 &bgwriter_lru_multiplier,
2052                 2.0, 0.0, 10.0, NULL, NULL
2053         },
2054
2055         {
2056                 {"seed", PGC_USERSET, UNGROUPED,
2057                         gettext_noop("Sets the seed for random-number generation."),
2058                         NULL,
2059                         GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2060                 },
2061                 &phony_random_seed,
2062                 0.0, -1.0, 1.0, assign_random_seed, show_random_seed
2063         },
2064
2065         {
2066                 {"autovacuum_vacuum_scale_factor", PGC_SIGHUP, AUTOVACUUM,
2067                         gettext_noop("Number of tuple updates or deletes prior to vacuum as a fraction of reltuples."),
2068                         NULL
2069                 },
2070                 &autovacuum_vac_scale,
2071                 0.2, 0.0, 100.0, NULL, NULL
2072         },
2073         {
2074                 {"autovacuum_analyze_scale_factor", PGC_SIGHUP, AUTOVACUUM,
2075                         gettext_noop("Number of tuple inserts, updates or deletes prior to analyze as a fraction of reltuples."),
2076                         NULL
2077                 },
2078                 &autovacuum_anl_scale,
2079                 0.1, 0.0, 100.0, NULL, NULL
2080         },
2081
2082         {
2083                 {"checkpoint_completion_target", PGC_SIGHUP, WAL_CHECKPOINTS,
2084                         gettext_noop("Time spent flushing dirty buffers during checkpoint, as fraction of checkpoint interval."),
2085                         NULL
2086                 },
2087                 &CheckPointCompletionTarget,
2088                 0.5, 0.0, 1.0, NULL, NULL
2089         },
2090
2091         /* End-of-list marker */
2092         {
2093                 {NULL, 0, 0, NULL, NULL}, NULL, 0.0, 0.0, 0.0, NULL, NULL
2094         }
2095 };
2096
2097
2098 static struct config_string ConfigureNamesString[] =
2099 {
2100         {
2101                 {"archive_command", PGC_SIGHUP, WAL_SETTINGS,
2102                         gettext_noop("Sets the shell command that will be called to archive a WAL file."),
2103                         NULL
2104                 },
2105                 &XLogArchiveCommand,
2106                 "", NULL, show_archive_command
2107         },
2108
2109         {
2110                 {"client_encoding", PGC_USERSET, CLIENT_CONN_LOCALE,
2111                         gettext_noop("Sets the client's character set encoding."),
2112                         NULL,
2113                         GUC_IS_NAME | GUC_REPORT
2114                 },
2115                 &client_encoding_string,
2116                 "SQL_ASCII", assign_client_encoding, NULL
2117         },
2118
2119         {
2120                 {"log_line_prefix", PGC_SIGHUP, LOGGING_WHAT,
2121                         gettext_noop("Controls information prefixed to each log line."),
2122                         gettext_noop("If blank, no prefix is used.")
2123                 },
2124                 &Log_line_prefix,
2125                 "", NULL, NULL
2126         },
2127
2128         {
2129                 {"log_timezone", PGC_SIGHUP, LOGGING_WHAT,
2130                         gettext_noop("Sets the time zone to use in log messages."),
2131                         NULL
2132                 },
2133                 &log_timezone_string,
2134                 "UNKNOWN", assign_log_timezone, show_log_timezone
2135         },
2136
2137         {
2138                 {"DateStyle", PGC_USERSET, CLIENT_CONN_LOCALE,
2139                         gettext_noop("Sets the display format for date and time values."),
2140                         gettext_noop("Also controls interpretation of ambiguous "
2141                                                  "date inputs."),
2142                         GUC_LIST_INPUT | GUC_REPORT
2143                 },
2144                 &datestyle_string,
2145                 "ISO, MDY", assign_datestyle, NULL
2146         },
2147
2148         {
2149                 {"default_tablespace", PGC_USERSET, CLIENT_CONN_STATEMENT,
2150                         gettext_noop("Sets the default tablespace to create tables and indexes in."),
2151                         gettext_noop("An empty string selects the database's default tablespace."),
2152                         GUC_IS_NAME
2153                 },
2154                 &default_tablespace,
2155                 "", assign_default_tablespace, NULL
2156         },
2157
2158         {
2159                 {"temp_tablespaces", PGC_USERSET, CLIENT_CONN_STATEMENT,
2160                         gettext_noop("Sets the tablespace(s) to use for temporary tables and sort files."),
2161                         NULL,
2162                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2163                 },
2164                 &temp_tablespaces,
2165                 "", assign_temp_tablespaces, NULL
2166         },
2167
2168         {
2169                 {"dynamic_library_path", PGC_SUSET, CLIENT_CONN_OTHER,
2170                         gettext_noop("Sets the path for dynamically loadable modules."),
2171                         gettext_noop("If a dynamically loadable module needs to be opened and "
2172                                                  "the specified name does not have a directory component (i.e., the "
2173                                                  "name does not contain a slash), the system will search this path for "
2174                                                  "the specified file."),
2175                         GUC_SUPERUSER_ONLY
2176                 },
2177                 &Dynamic_library_path,
2178                 "$libdir", NULL, NULL
2179         },
2180
2181         {
2182                 {"krb_server_keyfile", PGC_SIGHUP, CONN_AUTH_SECURITY,
2183                         gettext_noop("Sets the location of the Kerberos server key file."),
2184                         NULL,
2185                         GUC_SUPERUSER_ONLY
2186                 },
2187                 &pg_krb_server_keyfile,
2188                 PG_KRB_SRVTAB, NULL, NULL
2189         },
2190
2191         {
2192                 {"krb_srvname", PGC_SIGHUP, CONN_AUTH_SECURITY,
2193                         gettext_noop("Sets the name of the Kerberos service."),
2194                         NULL
2195                 },
2196                 &pg_krb_srvnam,
2197                 PG_KRB_SRVNAM, NULL, NULL
2198         },
2199
2200         {
2201                 {"bonjour_name", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2202                         gettext_noop("Sets the Bonjour broadcast service name."),
2203                         NULL
2204                 },
2205                 &bonjour_name,
2206                 "", NULL, NULL
2207         },
2208
2209         /* See main.c about why defaults for LC_foo are not all alike */
2210
2211         {
2212                 {"lc_collate", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2213                         gettext_noop("Shows the collation order locale."),
2214                         NULL,
2215                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2216                 },
2217                 &locale_collate,
2218                 "C", NULL, NULL
2219         },
2220
2221         {
2222                 {"lc_ctype", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2223                         gettext_noop("Shows the character classification and case conversion locale."),
2224                         NULL,
2225                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2226                 },
2227                 &locale_ctype,
2228                 "C", NULL, NULL
2229         },
2230
2231         {
2232                 {"lc_messages", PGC_SUSET, CLIENT_CONN_LOCALE,
2233                         gettext_noop("Sets the language in which messages are displayed."),
2234                         NULL
2235                 },
2236                 &locale_messages,
2237                 "", locale_messages_assign, NULL
2238         },
2239
2240         {
2241                 {"lc_monetary", PGC_USERSET, CLIENT_CONN_LOCALE,
2242                         gettext_noop("Sets the locale for formatting monetary amounts."),
2243                         NULL
2244                 },
2245                 &locale_monetary,
2246                 "C", locale_monetary_assign, NULL
2247         },
2248
2249         {
2250                 {"lc_numeric", PGC_USERSET, CLIENT_CONN_LOCALE,
2251                         gettext_noop("Sets the locale for formatting numbers."),
2252                         NULL
2253                 },
2254                 &locale_numeric,
2255                 "C", locale_numeric_assign, NULL
2256         },
2257
2258         {
2259                 {"lc_time", PGC_USERSET, CLIENT_CONN_LOCALE,
2260                         gettext_noop("Sets the locale for formatting date and time values."),
2261                         NULL
2262                 },
2263                 &locale_time,
2264                 "C", locale_time_assign, NULL
2265         },
2266
2267         {
2268                 {"shared_preload_libraries", PGC_POSTMASTER, RESOURCES_KERNEL,
2269                         gettext_noop("Lists shared libraries to preload into server."),
2270                         NULL,
2271                         GUC_LIST_INPUT | GUC_LIST_QUOTE | GUC_SUPERUSER_ONLY
2272                 },
2273                 &shared_preload_libraries_string,
2274                 "", NULL, NULL
2275         },
2276
2277         {
2278                 {"local_preload_libraries", PGC_BACKEND, CLIENT_CONN_OTHER,
2279                         gettext_noop("Lists shared libraries to preload into each backend."),
2280                         NULL,
2281                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2282                 },
2283                 &local_preload_libraries_string,
2284                 "", NULL, NULL
2285         },
2286
2287         {
2288                 {"search_path", PGC_USERSET, CLIENT_CONN_STATEMENT,
2289                         gettext_noop("Sets the schema search order for names that are not schema-qualified."),
2290                         NULL,
2291                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2292                 },
2293                 &namespace_search_path,
2294                 "\"$user\",public", assign_search_path, NULL
2295         },
2296
2297         {
2298                 /* Can't be set in postgresql.conf */
2299                 {"server_encoding", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2300                         gettext_noop("Sets the server (database) character set encoding."),
2301                         NULL,
2302                         GUC_IS_NAME | GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2303                 },
2304                 &server_encoding_string,
2305                 "SQL_ASCII", NULL, NULL
2306         },
2307
2308         {
2309                 /* Can't be set in postgresql.conf */
2310                 {"server_version", PGC_INTERNAL, PRESET_OPTIONS,
2311                         gettext_noop("Shows the server version."),
2312                         NULL,
2313                         GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2314                 },
2315                 &server_version_string,
2316                 PG_VERSION, NULL, NULL
2317         },
2318
2319         {
2320                 /* Not for general use --- used by SET ROLE */
2321                 {"role", PGC_USERSET, UNGROUPED,
2322                         gettext_noop("Sets the current role."),
2323                         NULL,
2324                         GUC_IS_NAME | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2325                 },
2326                 &role_string,
2327                 "none", assign_role, show_role
2328         },
2329
2330         {
2331                 /* Not for general use --- used by SET SESSION AUTHORIZATION */
2332                 {"session_authorization", PGC_USERSET, UNGROUPED,
2333                         gettext_noop("Sets the session user name."),
2334                         NULL,
2335                         GUC_IS_NAME | GUC_REPORT | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2336                 },
2337                 &session_authorization_string,
2338                 NULL, assign_session_authorization, show_session_authorization
2339         },
2340
2341         {
2342                 {"log_destination", PGC_SIGHUP, LOGGING_WHERE,
2343                         gettext_noop("Sets the destination for server log output."),
2344                         gettext_noop("Valid values are combinations of \"stderr\", "
2345                                                  "\"syslog\", \"csvlog\", and \"eventlog\", "
2346                                                  "depending on the platform."),
2347                         GUC_LIST_INPUT
2348                 },
2349                 &log_destination_string,
2350                 "stderr", assign_log_destination, NULL
2351         },
2352         {
2353                 {"log_directory", PGC_SIGHUP, LOGGING_WHERE,
2354                         gettext_noop("Sets the destination directory for log files."),
2355                         gettext_noop("Can be specified as relative to the data directory "
2356                                                  "or as absolute path."),
2357                         GUC_SUPERUSER_ONLY
2358                 },
2359                 &Log_directory,
2360                 "pg_log", assign_canonical_path, NULL
2361         },
2362         {
2363                 {"log_filename", PGC_SIGHUP, LOGGING_WHERE,
2364                         gettext_noop("Sets the file name pattern for log files."),
2365                         NULL,
2366                         GUC_SUPERUSER_ONLY
2367                 },
2368                 &Log_filename,
2369                 "postgresql-%Y-%m-%d_%H%M%S.log", NULL, NULL
2370         },
2371
2372 #ifdef HAVE_SYSLOG
2373         {
2374                 {"syslog_ident", PGC_SIGHUP, LOGGING_WHERE,
2375                         gettext_noop("Sets the program name used to identify PostgreSQL "
2376                                                  "messages in syslog."),
2377                         NULL
2378                 },
2379                 &syslog_ident_str,
2380                 "postgres", assign_syslog_ident, NULL
2381         },
2382 #endif
2383
2384         {
2385                 {"TimeZone", PGC_USERSET, CLIENT_CONN_LOCALE,
2386                         gettext_noop("Sets the time zone for displaying and interpreting time stamps."),
2387                         NULL,
2388                         GUC_REPORT
2389                 },
2390                 &timezone_string,
2391                 "UNKNOWN", assign_timezone, show_timezone
2392         },
2393         {
2394                 {"timezone_abbreviations", PGC_USERSET, CLIENT_CONN_LOCALE,
2395                         gettext_noop("Selects a file of time zone abbreviations."),
2396                         NULL
2397                 },
2398                 &timezone_abbreviations_string,
2399                 "UNKNOWN", assign_timezone_abbreviations, NULL
2400         },
2401
2402         {
2403                 {"transaction_isolation", PGC_USERSET, CLIENT_CONN_STATEMENT,
2404                         gettext_noop("Sets the current transaction's isolation level."),
2405                         NULL,
2406                         GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2407                 },
2408                 &XactIsoLevel_string,
2409                 NULL, assign_XactIsoLevel, show_XactIsoLevel
2410         },
2411
2412         {
2413                 {"unix_socket_group", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2414                         gettext_noop("Sets the owning group of the Unix-domain socket."),
2415                         gettext_noop("The owning user of the socket is always the user "
2416                                                  "that starts the server.")
2417                 },
2418                 &Unix_socket_group,
2419                 "", NULL, NULL
2420         },
2421
2422         {
2423                 {"unix_socket_directory", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2424                         gettext_noop("Sets the directory where the Unix-domain socket will be created."),
2425                         NULL,
2426                         GUC_SUPERUSER_ONLY
2427                 },
2428                 &UnixSocketDir,
2429                 "", assign_canonical_path, NULL
2430         },
2431
2432         {
2433                 {"listen_addresses", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2434                         gettext_noop("Sets the host name or IP address(es) to listen to."),
2435                         NULL,
2436                         GUC_LIST_INPUT
2437                 },
2438                 &ListenAddresses,
2439                 "localhost", NULL, NULL
2440         },
2441
2442         {
2443                 {"custom_variable_classes", PGC_SIGHUP, CUSTOM_OPTIONS,
2444                         gettext_noop("Sets the list of known custom variable classes."),
2445                         NULL,
2446                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2447                 },
2448                 &custom_variable_classes,
2449                 NULL, assign_custom_variable_classes, NULL
2450         },
2451
2452         {
2453                 {"data_directory", PGC_POSTMASTER, FILE_LOCATIONS,
2454                         gettext_noop("Sets the server's data directory."),
2455                         NULL,
2456                         GUC_SUPERUSER_ONLY
2457                 },
2458                 &data_directory,
2459                 NULL, NULL, NULL
2460         },
2461
2462         {
2463                 {"config_file", PGC_POSTMASTER, FILE_LOCATIONS,
2464                         gettext_noop("Sets the server's main configuration file."),
2465                         NULL,
2466                         GUC_DISALLOW_IN_FILE | GUC_SUPERUSER_ONLY
2467                 },
2468                 &ConfigFileName,
2469                 NULL, NULL, NULL
2470         },
2471
2472         {
2473                 {"hba_file", PGC_POSTMASTER, FILE_LOCATIONS,
2474                         gettext_noop("Sets the server's \"hba\" configuration file."),
2475                         NULL,
2476                         GUC_SUPERUSER_ONLY
2477                 },
2478                 &HbaFileName,
2479                 NULL, NULL, NULL
2480         },
2481
2482         {
2483                 {"ident_file", PGC_POSTMASTER, FILE_LOCATIONS,
2484                         gettext_noop("Sets the server's \"ident\" configuration file."),
2485                         NULL,
2486                         GUC_SUPERUSER_ONLY
2487                 },
2488                 &IdentFileName,
2489                 NULL, NULL, NULL
2490         },
2491
2492         {
2493                 {"external_pid_file", PGC_POSTMASTER, FILE_LOCATIONS,
2494                         gettext_noop("Writes the postmaster PID to the specified file."),
2495                         NULL,
2496                         GUC_SUPERUSER_ONLY
2497                 },
2498                 &external_pid_file,
2499                 NULL, assign_canonical_path, NULL
2500         },
2501
2502         {
2503                 {"stats_temp_directory", PGC_SIGHUP, STATS_COLLECTOR,
2504                         gettext_noop("Writes temporary statistics files to the specified directory."),
2505                         NULL,
2506                         GUC_SUPERUSER_ONLY
2507                 },
2508                 &pgstat_temp_directory,
2509                 "pg_stat_tmp", assign_pgstat_temp_directory, NULL
2510         },
2511
2512         {
2513                 {"default_text_search_config", PGC_USERSET, CLIENT_CONN_LOCALE,
2514                         gettext_noop("Sets default text search configuration."),
2515                         NULL
2516                 },
2517                 &TSCurrentConfig,
2518                 "pg_catalog.simple", assignTSCurrentConfig, NULL
2519         },
2520
2521 #ifdef USE_SSL
2522         {
2523                 {"ssl_ciphers", PGC_POSTMASTER, CONN_AUTH_SECURITY,
2524                         gettext_noop("Sets the list of allowed SSL ciphers."),
2525                         NULL,
2526                         GUC_SUPERUSER_ONLY
2527                 },
2528                 &SSLCipherSuites,
2529                 "ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH", NULL, NULL
2530         },
2531 #endif   /* USE_SSL */
2532
2533         /* End-of-list marker */
2534         {
2535                 {NULL, 0, 0, NULL, NULL}, NULL, NULL, NULL, NULL
2536         }
2537 };
2538
2539
2540 static struct config_enum ConfigureNamesEnum[] =
2541 {
2542         {
2543                 {"backslash_quote", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
2544                         gettext_noop("Sets whether \"\\'\" is allowed in string literals."),
2545                         NULL
2546                 },
2547                 &backslash_quote,
2548                 BACKSLASH_QUOTE_SAFE_ENCODING, backslash_quote_options, NULL, NULL
2549         },
2550
2551         {
2552                 {"bytea_output", PGC_USERSET, CLIENT_CONN_STATEMENT,
2553                         gettext_noop("Sets the output format for bytea."),
2554                         NULL
2555                 },
2556                 &bytea_output,
2557                 BYTEA_OUTPUT_HEX, bytea_output_options, NULL, NULL
2558         },
2559
2560         {
2561                 {"client_min_messages", PGC_USERSET, LOGGING_WHEN,
2562                         gettext_noop("Sets the message levels that are sent to the client."),
2563                         gettext_noop("Each level includes all the levels that follow it. The later"
2564                                                  " the level, the fewer messages are sent.")
2565                 },
2566                 &client_min_messages,
2567                 NOTICE, client_message_level_options, NULL, NULL
2568         },
2569
2570         {
2571                 {"constraint_exclusion", PGC_USERSET, QUERY_TUNING_OTHER,
2572                         gettext_noop("Enables the planner to use constraints to optimize queries."),
2573                         gettext_noop("Table scans will be skipped if their constraints"
2574                                                  " guarantee that no rows match the query.")
2575                 },
2576                 &constraint_exclusion,
2577                 CONSTRAINT_EXCLUSION_PARTITION, constraint_exclusion_options,
2578                 NULL, NULL
2579         },
2580
2581         {
2582                 {"default_transaction_isolation", PGC_USERSET, CLIENT_CONN_STATEMENT,
2583                         gettext_noop("Sets the transaction isolation level of each new transaction."),
2584                         NULL
2585                 },
2586                 &DefaultXactIsoLevel,
2587                 XACT_READ_COMMITTED, isolation_level_options, NULL, NULL
2588         },
2589
2590         {
2591                 {"IntervalStyle", PGC_USERSET, CLIENT_CONN_LOCALE,
2592                         gettext_noop("Sets the display format for interval values."),
2593                         NULL,
2594                         GUC_REPORT
2595                 },
2596                 &IntervalStyle,
2597                 INTSTYLE_POSTGRES, intervalstyle_options, NULL, NULL
2598         },
2599
2600         {
2601                 {"log_error_verbosity", PGC_SUSET, LOGGING_WHEN,
2602                         gettext_noop("Sets the verbosity of logged messages."),
2603                         NULL
2604                 },
2605                 &Log_error_verbosity,
2606                 PGERROR_DEFAULT, log_error_verbosity_options, NULL, NULL
2607         },
2608
2609         {
2610                 {"log_min_messages", PGC_SUSET, LOGGING_WHEN,
2611                         gettext_noop("Sets the message levels that are logged."),
2612                         gettext_noop("Each level includes all the levels that follow it. The later"
2613                                                  " the level, the fewer messages are sent.")
2614                 },
2615                 &log_min_messages,
2616                 WARNING, server_message_level_options, NULL, NULL
2617         },
2618
2619         {
2620                 {"log_min_error_statement", PGC_SUSET, LOGGING_WHEN,
2621                         gettext_noop("Causes all statements generating error at or above this level to be logged."),
2622                         gettext_noop("Each level includes all the levels that follow it. The later"
2623                                                  " the level, the fewer messages are sent.")
2624                 },
2625                 &log_min_error_statement,
2626                 ERROR, server_message_level_options, NULL, NULL
2627         },
2628
2629         {
2630                 {"log_statement", PGC_SUSET, LOGGING_WHAT,
2631                         gettext_noop("Sets the type of statements logged."),
2632                         NULL
2633                 },
2634                 &log_statement,
2635                 LOGSTMT_NONE, log_statement_options, NULL, NULL
2636         },
2637
2638 #ifdef HAVE_SYSLOG
2639         {
2640                 {"syslog_facility", PGC_SIGHUP, LOGGING_WHERE,
2641                         gettext_noop("Sets the syslog \"facility\" to be used when syslog enabled."),
2642                         NULL
2643                 },
2644                 &syslog_facility,
2645                 LOG_LOCAL0, syslog_facility_options, assign_syslog_facility, NULL
2646         },
2647 #endif
2648
2649         {
2650                 {"regex_flavor", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
2651                         gettext_noop("Sets the regular expression \"flavor\"."),
2652                         NULL
2653                 },
2654                 &regex_flavor,
2655                 REG_ADVANCED, regex_flavor_options, NULL, NULL
2656         },
2657
2658         {
2659                 {"session_replication_role", PGC_SUSET, CLIENT_CONN_STATEMENT,
2660                         gettext_noop("Sets the session's behavior for triggers and rewrite rules."),
2661                         NULL
2662                 },
2663                 &SessionReplicationRole,
2664                 SESSION_REPLICATION_ROLE_ORIGIN, session_replication_role_options,
2665                 assign_session_replication_role, NULL
2666         },
2667
2668         {
2669                 {"track_functions", PGC_SUSET, STATS_COLLECTOR,
2670                         gettext_noop("Collects function-level statistics on database activity."),
2671                         NULL
2672                 },
2673                 &pgstat_track_functions,
2674                 TRACK_FUNC_OFF, track_function_options, NULL, NULL
2675         },
2676
2677         {
2678                 {"wal_sync_method", PGC_SIGHUP, WAL_SETTINGS,
2679                         gettext_noop("Selects the method used for forcing WAL updates to disk."),
2680                         NULL
2681                 },
2682                 &sync_method,
2683                 DEFAULT_SYNC_METHOD, sync_method_options,
2684                 assign_xlog_sync_method, NULL
2685         },
2686
2687         {
2688                 {"xmlbinary", PGC_USERSET, CLIENT_CONN_STATEMENT,
2689                         gettext_noop("Sets how binary values are to be encoded in XML."),
2690                         NULL
2691                 },
2692                 &xmlbinary,
2693                 XMLBINARY_BASE64, xmlbinary_options, NULL, NULL
2694         },
2695
2696         {
2697                 {"xmloption", PGC_USERSET, CLIENT_CONN_STATEMENT,
2698                         gettext_noop("Sets whether XML data in implicit parsing and serialization "
2699                                                  "operations is to be considered as documents or content fragments."),
2700                         NULL
2701                 },
2702                 &xmloption,
2703                 XMLOPTION_CONTENT, xmloption_options, NULL, NULL
2704         },
2705
2706
2707         /* End-of-list marker */
2708         {
2709                 {NULL, 0, 0, NULL, NULL}, NULL, 0, NULL, NULL, NULL
2710         }
2711 };
2712
2713 /******** end of options list ********/
2714
2715
2716 /*
2717  * To allow continued support of obsolete names for GUC variables, we apply
2718  * the following mappings to any unrecognized name.  Note that an old name
2719  * should be mapped to a new one only if the new variable has very similar
2720  * semantics to the old.
2721  */
2722 static const char *const map_old_guc_names[] = {
2723         "sort_mem", "work_mem",
2724         "vacuum_mem", "maintenance_work_mem",
2725         NULL
2726 };
2727
2728
2729 /*
2730  * Actual lookup of variables is done through this single, sorted array.
2731  */
2732 static struct config_generic **guc_variables;
2733
2734 /* Current number of variables contained in the vector */
2735 static int      num_guc_variables;
2736
2737 /* Vector capacity */
2738 static int      size_guc_variables;
2739
2740
2741 static bool guc_dirty;                  /* TRUE if need to do commit/abort work */
2742
2743 static bool reporting_enabled;  /* TRUE to enable GUC_REPORT */
2744
2745 static int      GUCNestLevel = 0;       /* 1 when in main transaction */
2746
2747
2748 static int      guc_var_compare(const void *a, const void *b);
2749 static int      guc_name_compare(const char *namea, const char *nameb);
2750 static void InitializeOneGUCOption(struct config_generic * gconf);
2751 static void push_old_value(struct config_generic * gconf, GucAction action);
2752 static void ReportGUCOption(struct config_generic * record);
2753 static void ShowGUCConfigOption(const char *name, DestReceiver *dest);
2754 static void ShowAllGUCConfig(DestReceiver *dest);
2755 static char *_ShowOption(struct config_generic * record, bool use_units);
2756 static bool is_newvalue_equal(struct config_generic * record, const char *newvalue);
2757
2758
2759 /*
2760  * Some infrastructure for checking malloc/strdup/realloc calls
2761  */
2762 static void *
2763 guc_malloc(int elevel, size_t size)
2764 {
2765         void       *data;
2766
2767         data = malloc(size);
2768         if (data == NULL)
2769                 ereport(elevel,
2770                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2771                                  errmsg("out of memory")));
2772         return data;
2773 }
2774
2775 static void *
2776 guc_realloc(int elevel, void *old, size_t size)
2777 {
2778         void       *data;
2779
2780         data = realloc(old, size);
2781         if (data == NULL)
2782                 ereport(elevel,
2783                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2784                                  errmsg("out of memory")));
2785         return data;
2786 }
2787
2788 static char *
2789 guc_strdup(int elevel, const char *src)
2790 {
2791         char       *data;
2792
2793         data = strdup(src);
2794         if (data == NULL)
2795                 ereport(elevel,
2796                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2797                                  errmsg("out of memory")));
2798         return data;
2799 }
2800
2801
2802 /*
2803  * Support for assigning to a field of a string GUC item.  Free the prior
2804  * value if it's not referenced anywhere else in the item (including stacked
2805  * states).
2806  */
2807 static void
2808 set_string_field(struct config_string * conf, char **field, char *newval)
2809 {
2810         char       *oldval = *field;
2811         GucStack   *stack;
2812
2813         /* Do the assignment */
2814         *field = newval;
2815
2816         /* Exit if any duplicate references, or if old value was NULL anyway */
2817         if (oldval == NULL ||
2818                 oldval == *(conf->variable) ||
2819                 oldval == conf->reset_val ||
2820                 oldval == conf->boot_val)
2821                 return;
2822         for (stack = conf->gen.stack; stack; stack = stack->prev)
2823         {
2824                 if (oldval == stack->prior.stringval ||
2825                         oldval == stack->masked.stringval)
2826                         return;
2827         }
2828
2829         /* Not used anymore, so free it */
2830         free(oldval);
2831 }
2832
2833 /*
2834  * Detect whether strval is referenced anywhere in a GUC string item
2835  */
2836 static bool
2837 string_field_used(struct config_string * conf, char *strval)
2838 {
2839         GucStack   *stack;
2840
2841         if (strval == *(conf->variable) ||
2842                 strval == conf->reset_val ||
2843                 strval == conf->boot_val)
2844                 return true;
2845         for (stack = conf->gen.stack; stack; stack = stack->prev)
2846         {
2847                 if (strval == stack->prior.stringval ||
2848                         strval == stack->masked.stringval)
2849                         return true;
2850         }
2851         return false;
2852 }
2853
2854 /*
2855  * Support for copying a variable's active value into a stack entry
2856  */
2857 static void
2858 set_stack_value(struct config_generic * gconf, union config_var_value * val)
2859 {
2860         switch (gconf->vartype)
2861         {
2862                 case PGC_BOOL:
2863                         val->boolval =
2864                                 *((struct config_bool *) gconf)->variable;
2865                         break;
2866                 case PGC_INT:
2867                         val->intval =
2868                                 *((struct config_int *) gconf)->variable;
2869                         break;
2870                 case PGC_REAL:
2871                         val->realval =
2872                                 *((struct config_real *) gconf)->variable;
2873                         break;
2874                 case PGC_STRING:
2875                         /* we assume stringval is NULL if not valid */
2876                         set_string_field((struct config_string *) gconf,
2877                                                          &(val->stringval),
2878                                                          *((struct config_string *) gconf)->variable);
2879                         break;
2880                 case PGC_ENUM:
2881                         val->enumval =
2882                                 *((struct config_enum *) gconf)->variable;
2883                         break;
2884         }
2885 }
2886
2887 /*
2888  * Support for discarding a no-longer-needed value in a stack entry
2889  */
2890 static void
2891 discard_stack_value(struct config_generic * gconf, union config_var_value * val)
2892 {
2893         switch (gconf->vartype)
2894         {
2895                 case PGC_BOOL:
2896                 case PGC_INT:
2897                 case PGC_REAL:
2898                 case PGC_ENUM:
2899                         /* no need to do anything */
2900                         break;
2901                 case PGC_STRING:
2902                         set_string_field((struct config_string *) gconf,
2903                                                          &(val->stringval),
2904                                                          NULL);
2905                         break;
2906         }
2907 }
2908
2909
2910 /*
2911  * Fetch the sorted array pointer (exported for help_config.c's use ONLY)
2912  */
2913 struct config_generic **
2914 get_guc_variables(void)
2915 {
2916         return guc_variables;
2917 }
2918
2919
2920 /*
2921  * Build the sorted array.      This is split out so that it could be
2922  * re-executed after startup (eg, we could allow loadable modules to
2923  * add vars, and then we'd need to re-sort).
2924  */
2925 void
2926 build_guc_variables(void)
2927 {
2928         int                     size_vars;
2929         int                     num_vars = 0;
2930         struct config_generic **guc_vars;
2931         int                     i;
2932
2933         for (i = 0; ConfigureNamesBool[i].gen.name; i++)
2934         {
2935                 struct config_bool *conf = &ConfigureNamesBool[i];
2936
2937                 /* Rather than requiring vartype to be filled in by hand, do this: */
2938                 conf->gen.vartype = PGC_BOOL;
2939                 num_vars++;
2940         }
2941
2942         for (i = 0; ConfigureNamesInt[i].gen.name; i++)
2943         {
2944                 struct config_int *conf = &ConfigureNamesInt[i];
2945
2946                 conf->gen.vartype = PGC_INT;
2947                 num_vars++;
2948         }
2949
2950         for (i = 0; ConfigureNamesReal[i].gen.name; i++)
2951         {
2952                 struct config_real *conf = &ConfigureNamesReal[i];
2953
2954                 conf->gen.vartype = PGC_REAL;
2955                 num_vars++;
2956         }
2957
2958         for (i = 0; ConfigureNamesString[i].gen.name; i++)
2959         {
2960                 struct config_string *conf = &ConfigureNamesString[i];
2961
2962                 conf->gen.vartype = PGC_STRING;
2963                 num_vars++;
2964         }
2965
2966         for (i = 0; ConfigureNamesEnum[i].gen.name; i++)
2967         {
2968                 struct config_enum *conf = &ConfigureNamesEnum[i];
2969
2970                 conf->gen.vartype = PGC_ENUM;
2971                 num_vars++;
2972         }
2973
2974         /*
2975          * Create table with 20% slack
2976          */
2977         size_vars = num_vars + num_vars / 4;
2978
2979         guc_vars = (struct config_generic **)
2980                 guc_malloc(FATAL, size_vars * sizeof(struct config_generic *));
2981
2982         num_vars = 0;
2983
2984         for (i = 0; ConfigureNamesBool[i].gen.name; i++)
2985                 guc_vars[num_vars++] = &ConfigureNamesBool[i].gen;
2986
2987         for (i = 0; ConfigureNamesInt[i].gen.name; i++)
2988                 guc_vars[num_vars++] = &ConfigureNamesInt[i].gen;
2989
2990         for (i = 0; ConfigureNamesReal[i].gen.name; i++)
2991                 guc_vars[num_vars++] = &ConfigureNamesReal[i].gen;
2992
2993         for (i = 0; ConfigureNamesString[i].gen.name; i++)
2994                 guc_vars[num_vars++] = &ConfigureNamesString[i].gen;
2995
2996         for (i = 0; ConfigureNamesEnum[i].gen.name; i++)
2997                 guc_vars[num_vars++] = &ConfigureNamesEnum[i].gen;
2998
2999         if (guc_variables)
3000                 free(guc_variables);
3001         guc_variables = guc_vars;
3002         num_guc_variables = num_vars;
3003         size_guc_variables = size_vars;
3004         qsort((void *) guc_variables, num_guc_variables,
3005                   sizeof(struct config_generic *), guc_var_compare);
3006 }
3007
3008 /*
3009  * Add a new GUC variable to the list of known variables. The
3010  * list is expanded if needed.
3011  */
3012 static bool
3013 add_guc_variable(struct config_generic * var, int elevel)
3014 {
3015         if (num_guc_variables + 1 >= size_guc_variables)
3016         {
3017                 /*
3018                  * Increase the vector by 25%
3019                  */
3020                 int                     size_vars = size_guc_variables + size_guc_variables / 4;
3021                 struct config_generic **guc_vars;
3022
3023                 if (size_vars == 0)
3024                 {
3025                         size_vars = 100;
3026                         guc_vars = (struct config_generic **)
3027                                 guc_malloc(elevel, size_vars * sizeof(struct config_generic *));
3028                 }
3029                 else
3030                 {
3031                         guc_vars = (struct config_generic **)
3032                                 guc_realloc(elevel, guc_variables, size_vars * sizeof(struct config_generic *));
3033                 }
3034
3035                 if (guc_vars == NULL)
3036                         return false;           /* out of memory */
3037
3038                 guc_variables = guc_vars;
3039                 size_guc_variables = size_vars;
3040         }
3041         guc_variables[num_guc_variables++] = var;
3042         qsort((void *) guc_variables, num_guc_variables,
3043                   sizeof(struct config_generic *), guc_var_compare);
3044         return true;
3045 }
3046
3047 /*
3048  * Create and add a placeholder variable. It's presumed to belong
3049  * to a valid custom variable class at this point.
3050  */
3051 static struct config_generic *
3052 add_placeholder_variable(const char *name, int elevel)
3053 {
3054         size_t          sz = sizeof(struct config_string) + sizeof(char *);
3055         struct config_string *var;
3056         struct config_generic *gen;
3057
3058         var = (struct config_string *) guc_malloc(elevel, sz);
3059         if (var == NULL)
3060                 return NULL;
3061         memset(var, 0, sz);
3062         gen = &var->gen;
3063
3064         gen->name = guc_strdup(elevel, name);
3065         if (gen->name == NULL)
3066         {
3067                 free(var);
3068                 return NULL;
3069         }
3070
3071         gen->context = PGC_USERSET;
3072         gen->group = CUSTOM_OPTIONS;
3073         gen->short_desc = "GUC placeholder variable";
3074         gen->flags = GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE | GUC_CUSTOM_PLACEHOLDER;
3075         gen->vartype = PGC_STRING;
3076
3077         /*
3078          * The char* is allocated at the end of the struct since we have no
3079          * 'static' place to point to.  Note that the current value, as well as
3080          * the boot and reset values, start out NULL.
3081          */
3082         var->variable = (char **) (var + 1);
3083
3084         if (!add_guc_variable((struct config_generic *) var, elevel))
3085         {
3086                 free((void *) gen->name);
3087                 free(var);
3088                 return NULL;
3089         }
3090
3091         return gen;
3092 }
3093
3094 /*
3095  * Detect whether the portion of "name" before dotPos matches any custom
3096  * variable class name listed in custom_var_classes.  The latter must be
3097  * formatted the way that assign_custom_variable_classes does it, ie,
3098  * no whitespace.  NULL is valid for custom_var_classes.
3099  */
3100 static bool
3101 is_custom_class(const char *name, int dotPos, const char *custom_var_classes)
3102 {
3103         bool            result = false;
3104         const char *ccs = custom_var_classes;
3105
3106         if (ccs != NULL)
3107         {
3108                 const char *start = ccs;
3109
3110                 for (;; ++ccs)
3111                 {
3112                         char            c = *ccs;
3113
3114                         if (c == '\0' || c == ',')
3115                         {
3116                                 if (dotPos == ccs - start && strncmp(start, name, dotPos) == 0)
3117                                 {
3118                                         result = true;
3119                                         break;
3120                                 }
3121                                 if (c == '\0')
3122                                         break;
3123                                 start = ccs + 1;
3124                         }
3125                 }
3126         }
3127         return result;
3128 }
3129
3130 /*
3131  * Look up option NAME.  If it exists, return a pointer to its record,
3132  * else return NULL.  If create_placeholders is TRUE, we'll create a
3133  * placeholder record for a valid-looking custom variable name.
3134  */
3135 static struct config_generic *
3136 find_option(const char *name, bool create_placeholders, int elevel)
3137 {
3138         const char **key = &name;
3139         struct config_generic **res;
3140         int                     i;
3141
3142         Assert(name);
3143
3144         /*
3145          * By equating const char ** with struct config_generic *, we are assuming
3146          * the name field is first in config_generic.
3147          */
3148         res = (struct config_generic **) bsearch((void *) &key,
3149                                                                                          (void *) guc_variables,
3150                                                                                          num_guc_variables,
3151                                                                                          sizeof(struct config_generic *),
3152                                                                                          guc_var_compare);
3153         if (res)
3154                 return *res;
3155
3156         /*
3157          * See if the name is an obsolete name for a variable.  We assume that the
3158          * set of supported old names is short enough that a brute-force search is
3159          * the best way.
3160          */
3161         for (i = 0; map_old_guc_names[i] != NULL; i += 2)
3162         {
3163                 if (guc_name_compare(name, map_old_guc_names[i]) == 0)
3164                         return find_option(map_old_guc_names[i + 1], false, elevel);
3165         }
3166
3167         if (create_placeholders)
3168         {
3169                 /*
3170                  * Check if the name is qualified, and if so, check if the qualifier
3171                  * matches any custom variable class.  If so, add a placeholder.
3172                  */
3173                 const char *dot = strchr(name, GUC_QUALIFIER_SEPARATOR);
3174
3175                 if (dot != NULL &&
3176                         is_custom_class(name, dot - name, custom_variable_classes))
3177                         return add_placeholder_variable(name, elevel);
3178         }
3179
3180         /* Unknown name */
3181         return NULL;
3182 }
3183
3184
3185 /*
3186  * comparator for qsorting and bsearching guc_variables array
3187  */
3188 static int
3189 guc_var_compare(const void *a, const void *b)
3190 {
3191         struct config_generic *confa = *(struct config_generic **) a;
3192         struct config_generic *confb = *(struct config_generic **) b;
3193
3194         return guc_name_compare(confa->name, confb->name);
3195 }
3196
3197 /*
3198  * the bare comparison function for GUC names
3199  */
3200 static int
3201 guc_name_compare(const char *namea, const char *nameb)
3202 {
3203         /*
3204          * The temptation to use strcasecmp() here must be resisted, because the
3205          * array ordering has to remain stable across setlocale() calls. So, build
3206          * our own with a simple ASCII-only downcasing.
3207          */
3208         while (*namea && *nameb)
3209         {
3210                 char            cha = *namea++;
3211                 char            chb = *nameb++;
3212
3213                 if (cha >= 'A' && cha <= 'Z')
3214                         cha += 'a' - 'A';
3215                 if (chb >= 'A' && chb <= 'Z')
3216                         chb += 'a' - 'A';
3217                 if (cha != chb)
3218                         return cha - chb;
3219         }
3220         if (*namea)
3221                 return 1;                               /* a is longer */
3222         if (*nameb)
3223                 return -1;                              /* b is longer */
3224         return 0;
3225 }
3226
3227
3228 /*
3229  * Initialize GUC options during program startup.
3230  *
3231  * Note that we cannot read the config file yet, since we have not yet
3232  * processed command-line switches.
3233  */
3234 void
3235 InitializeGUCOptions(void)
3236 {
3237         int                     i;
3238         char       *env;
3239         long            stack_rlimit;
3240
3241         /*
3242          * Before log_line_prefix could possibly receive a nonempty setting, make
3243          * sure that timezone processing is minimally alive (see elog.c).
3244          */
3245         pg_timezone_pre_initialize();
3246
3247         /*
3248          * Build sorted array of all GUC variables.
3249          */
3250         build_guc_variables();
3251
3252         /*
3253          * Load all variables with their compiled-in defaults, and initialize
3254          * status fields as needed.
3255          */
3256         for (i = 0; i < num_guc_variables; i++)
3257         {
3258                 InitializeOneGUCOption(guc_variables[i]);
3259         }
3260
3261         guc_dirty = false;
3262
3263         reporting_enabled = false;
3264
3265         /*
3266          * Prevent any attempt to override the transaction modes from
3267          * non-interactive sources.
3268          */
3269         SetConfigOption("transaction_isolation", "default",
3270                                         PGC_POSTMASTER, PGC_S_OVERRIDE);
3271         SetConfigOption("transaction_read_only", "no",
3272                                         PGC_POSTMASTER, PGC_S_OVERRIDE);
3273
3274         /*
3275          * For historical reasons, some GUC parameters can receive defaults from
3276          * environment variables.  Process those settings.      NB: if you add or
3277          * remove anything here, see also ProcessConfigFile().
3278          */
3279
3280         env = getenv("PGPORT");
3281         if (env != NULL)
3282                 SetConfigOption("port", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3283
3284         env = getenv("PGDATESTYLE");
3285         if (env != NULL)
3286                 SetConfigOption("datestyle", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3287
3288         env = getenv("PGCLIENTENCODING");
3289         if (env != NULL)
3290                 SetConfigOption("client_encoding", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3291
3292         /*
3293          * rlimit isn't exactly an "environment variable", but it behaves about
3294          * the same.  If we can identify the platform stack depth rlimit, increase
3295          * default stack depth setting up to whatever is safe (but at most 2MB).
3296          */
3297         stack_rlimit = get_stack_depth_rlimit();
3298         if (stack_rlimit > 0)
3299         {
3300                 int                     new_limit = (stack_rlimit - STACK_DEPTH_SLOP) / 1024L;
3301
3302                 if (new_limit > 100)
3303                 {
3304                         char            limbuf[16];
3305
3306                         new_limit = Min(new_limit, 2048);
3307                         sprintf(limbuf, "%d", new_limit);
3308                         SetConfigOption("max_stack_depth", limbuf,
3309                                                         PGC_POSTMASTER, PGC_S_ENV_VAR);
3310                 }
3311         }
3312 }
3313
3314 /*
3315  * Initialize one GUC option variable to its compiled-in default.
3316  */
3317 static void
3318 InitializeOneGUCOption(struct config_generic * gconf)
3319 {
3320         gconf->status = 0;
3321         gconf->reset_source = PGC_S_DEFAULT;
3322         gconf->source = PGC_S_DEFAULT;
3323         gconf->stack = NULL;
3324         gconf->sourcefile = NULL;
3325         gconf->sourceline = 0;
3326
3327         switch (gconf->vartype)
3328         {
3329                 case PGC_BOOL:
3330                         {
3331                                 struct config_bool *conf = (struct config_bool *) gconf;
3332
3333                                 if (conf->assign_hook)
3334                                         if (!(*conf->assign_hook) (conf->boot_val, true,
3335                                                                                            PGC_S_DEFAULT))
3336                                                 elog(FATAL, "failed to initialize %s to %d",
3337                                                          conf->gen.name, (int) conf->boot_val);
3338                                 *conf->variable = conf->reset_val = conf->boot_val;
3339                                 break;
3340                         }
3341                 case PGC_INT:
3342                         {
3343                                 struct config_int *conf = (struct config_int *) gconf;
3344
3345                                 Assert(conf->boot_val >= conf->min);
3346                                 Assert(conf->boot_val <= conf->max);
3347                                 if (conf->assign_hook)
3348                                         if (!(*conf->assign_hook) (conf->boot_val, true,
3349                                                                                            PGC_S_DEFAULT))
3350                                                 elog(FATAL, "failed to initialize %s to %d",
3351                                                          conf->gen.name, conf->boot_val);
3352                                 *conf->variable = conf->reset_val = conf->boot_val;
3353                                 break;
3354                         }
3355                 case PGC_REAL:
3356                         {
3357                                 struct config_real *conf = (struct config_real *) gconf;
3358
3359                                 Assert(conf->boot_val >= conf->min);
3360                                 Assert(conf->boot_val <= conf->max);
3361                                 if (conf->assign_hook)
3362                                         if (!(*conf->assign_hook) (conf->boot_val, true,
3363                                                                                            PGC_S_DEFAULT))
3364                                                 elog(FATAL, "failed to initialize %s to %g",
3365                                                          conf->gen.name, conf->boot_val);
3366                                 *conf->variable = conf->reset_val = conf->boot_val;
3367                                 break;
3368                         }
3369                 case PGC_STRING:
3370                         {
3371                                 struct config_string *conf = (struct config_string *) gconf;
3372                                 char       *str;
3373
3374                                 *conf->variable = NULL;
3375                                 conf->reset_val = NULL;
3376
3377                                 if (conf->boot_val == NULL)
3378                                 {
3379                                         /* leave the value NULL, do not call assign hook */
3380                                         break;
3381                                 }
3382
3383                                 str = guc_strdup(FATAL, conf->boot_val);
3384                                 conf->reset_val = str;
3385
3386                                 if (conf->assign_hook)
3387                                 {
3388                                         const char *newstr;
3389
3390                                         newstr = (*conf->assign_hook) (str, true,
3391                                                                                                    PGC_S_DEFAULT);
3392                                         if (newstr == NULL)
3393                                         {
3394                                                 elog(FATAL, "failed to initialize %s to \"%s\"",
3395                                                          conf->gen.name, str);
3396                                         }
3397                                         else if (newstr != str)
3398                                         {
3399                                                 free(str);
3400
3401                                                 /*
3402                                                  * See notes in set_config_option about casting
3403                                                  */
3404                                                 str = (char *) newstr;
3405                                                 conf->reset_val = str;
3406                                         }
3407                                 }
3408                                 *conf->variable = str;
3409                                 break;
3410                         }
3411                 case PGC_ENUM:
3412                         {
3413                                 struct config_enum *conf = (struct config_enum *) gconf;
3414
3415                                 if (conf->assign_hook)
3416                                         if (!(*conf->assign_hook) (conf->boot_val, true,
3417                                                                                            PGC_S_DEFAULT))
3418                                                 elog(FATAL, "failed to initialize %s to %s",
3419                                                          conf->gen.name,
3420                                                   config_enum_lookup_by_value(conf, conf->boot_val));
3421                                 *conf->variable = conf->reset_val = conf->boot_val;
3422                                 break;
3423                         }
3424         }
3425 }
3426
3427
3428 /*
3429  * Select the configuration files and data directory to be used, and
3430  * do the initial read of postgresql.conf.
3431  *
3432  * This is called after processing command-line switches.
3433  *              userDoption is the -D switch value if any (NULL if unspecified).
3434  *              progname is just for use in error messages.
3435  *
3436  * Returns true on success; on failure, prints a suitable error message
3437  * to stderr and returns false.
3438  */
3439 bool
3440 SelectConfigFiles(const char *userDoption, const char *progname)
3441 {
3442         char       *configdir;
3443         char       *fname;
3444         struct stat stat_buf;
3445
3446         /* configdir is -D option, or $PGDATA if no -D */
3447         if (userDoption)
3448                 configdir = make_absolute_path(userDoption);
3449         else
3450                 configdir = make_absolute_path(getenv("PGDATA"));
3451
3452         /*
3453          * Find the configuration file: if config_file was specified on the
3454          * command line, use it, else use configdir/postgresql.conf.  In any case
3455          * ensure the result is an absolute path, so that it will be interpreted
3456          * the same way by future backends.
3457          */
3458         if (ConfigFileName)
3459                 fname = make_absolute_path(ConfigFileName);
3460         else if (configdir)
3461         {
3462                 fname = guc_malloc(FATAL,
3463                                                    strlen(configdir) + strlen(CONFIG_FILENAME) + 2);
3464                 sprintf(fname, "%s/%s", configdir, CONFIG_FILENAME);
3465         }
3466         else
3467         {
3468                 write_stderr("%s does not know where to find the server configuration file.\n"
3469                                          "You must specify the --config-file or -D invocation "
3470                                          "option or set the PGDATA environment variable.\n",
3471                                          progname);
3472                 return false;
3473         }
3474
3475         /*
3476          * Set the ConfigFileName GUC variable to its final value, ensuring that
3477          * it can't be overridden later.
3478          */
3479         SetConfigOption("config_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3480         free(fname);
3481
3482         /*
3483          * Now read the config file for the first time.
3484          */
3485         if (stat(ConfigFileName, &stat_buf) != 0)
3486         {
3487                 write_stderr("%s cannot access the server configuration file \"%s\": %s\n",
3488                                          progname, ConfigFileName, strerror(errno));
3489                 return false;
3490         }
3491
3492         ProcessConfigFile(PGC_POSTMASTER);
3493
3494         /*
3495          * If the data_directory GUC variable has been set, use that as DataDir;
3496          * otherwise use configdir if set; else punt.
3497          *
3498          * Note: SetDataDir will copy and absolute-ize its argument, so we don't
3499          * have to.
3500          */
3501         if (data_directory)
3502                 SetDataDir(data_directory);
3503         else if (configdir)
3504                 SetDataDir(configdir);
3505         else
3506         {
3507                 write_stderr("%s does not know where to find the database system data.\n"
3508                                          "This can be specified as \"data_directory\" in \"%s\", "
3509                                          "or by the -D invocation option, or by the "
3510                                          "PGDATA environment variable.\n",
3511                                          progname, ConfigFileName);
3512                 return false;
3513         }
3514
3515         /*
3516          * Reflect the final DataDir value back into the data_directory GUC var.
3517          * (If you are wondering why we don't just make them a single variable,
3518          * it's because the EXEC_BACKEND case needs DataDir to be transmitted to
3519          * child backends specially.  XXX is that still true?  Given that we now
3520          * chdir to DataDir, EXEC_BACKEND can read the config file without knowing
3521          * DataDir in advance.)
3522          */
3523         SetConfigOption("data_directory", DataDir, PGC_POSTMASTER, PGC_S_OVERRIDE);
3524
3525         /*
3526          * Figure out where pg_hba.conf is, and make sure the path is absolute.
3527          */
3528         if (HbaFileName)
3529                 fname = make_absolute_path(HbaFileName);
3530         else if (configdir)
3531         {
3532                 fname = guc_malloc(FATAL,
3533                                                    strlen(configdir) + strlen(HBA_FILENAME) + 2);
3534                 sprintf(fname, "%s/%s", configdir, HBA_FILENAME);
3535         }
3536         else
3537         {
3538                 write_stderr("%s does not know where to find the \"hba\" configuration file.\n"
3539                                          "This can be specified as \"hba_file\" in \"%s\", "
3540                                          "or by the -D invocation option, or by the "
3541                                          "PGDATA environment variable.\n",
3542                                          progname, ConfigFileName);
3543                 return false;
3544         }
3545         SetConfigOption("hba_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3546         free(fname);
3547
3548         /*
3549          * Likewise for pg_ident.conf.
3550          */
3551         if (IdentFileName)
3552                 fname = make_absolute_path(IdentFileName);
3553         else if (configdir)
3554         {
3555                 fname = guc_malloc(FATAL,
3556                                                    strlen(configdir) + strlen(IDENT_FILENAME) + 2);
3557                 sprintf(fname, "%s/%s", configdir, IDENT_FILENAME);
3558         }
3559         else
3560         {
3561                 write_stderr("%s does not know where to find the \"ident\" configuration file.\n"
3562                                          "This can be specified as \"ident_file\" in \"%s\", "
3563                                          "or by the -D invocation option, or by the "
3564                                          "PGDATA environment variable.\n",
3565                                          progname, ConfigFileName);
3566                 return false;
3567         }
3568         SetConfigOption("ident_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3569         free(fname);
3570
3571         free(configdir);
3572
3573         return true;
3574 }
3575
3576
3577 /*
3578  * Reset all options to their saved default values (implements RESET ALL)
3579  */
3580 void
3581 ResetAllOptions(void)
3582 {
3583         int                     i;
3584
3585         for (i = 0; i < num_guc_variables; i++)
3586         {
3587                 struct config_generic *gconf = guc_variables[i];
3588
3589                 /* Don't reset non-SET-able values */
3590                 if (gconf->context != PGC_SUSET &&
3591                         gconf->context != PGC_USERSET)
3592                         continue;
3593                 /* Don't reset if special exclusion from RESET ALL */
3594                 if (gconf->flags & GUC_NO_RESET_ALL)
3595                         continue;
3596                 /* No need to reset if wasn't SET */
3597                 if (gconf->source <= PGC_S_OVERRIDE)
3598                         continue;
3599
3600                 /* Save old value to support transaction abort */
3601                 push_old_value(gconf, GUC_ACTION_SET);
3602
3603                 switch (gconf->vartype)
3604                 {
3605                         case PGC_BOOL:
3606                                 {
3607                                         struct config_bool *conf = (struct config_bool *) gconf;
3608
3609                                         if (conf->assign_hook)
3610                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3611                                                                                                    PGC_S_SESSION))
3612                                                         elog(ERROR, "failed to reset %s to %d",
3613                                                                  conf->gen.name, (int) conf->reset_val);
3614                                         *conf->variable = conf->reset_val;
3615                                         break;
3616                                 }
3617                         case PGC_INT:
3618                                 {
3619                                         struct config_int *conf = (struct config_int *) gconf;
3620
3621                                         if (conf->assign_hook)
3622                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3623                                                                                                    PGC_S_SESSION))
3624                                                         elog(ERROR, "failed to reset %s to %d",
3625                                                                  conf->gen.name, conf->reset_val);
3626                                         *conf->variable = conf->reset_val;
3627                                         break;
3628                                 }
3629                         case PGC_REAL:
3630                                 {
3631                                         struct config_real *conf = (struct config_real *) gconf;
3632
3633                                         if (conf->assign_hook)
3634                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3635                                                                                                    PGC_S_SESSION))
3636                                                         elog(ERROR, "failed to reset %s to %g",
3637                                                                  conf->gen.name, conf->reset_val);
3638                                         *conf->variable = conf->reset_val;
3639                                         break;
3640                                 }
3641                         case PGC_STRING:
3642                                 {
3643                                         struct config_string *conf = (struct config_string *) gconf;
3644                                         char       *str;
3645
3646                                         /* We need not strdup here */
3647                                         str = conf->reset_val;
3648
3649                                         if (conf->assign_hook && str)
3650                                         {
3651                                                 const char *newstr;
3652
3653                                                 newstr = (*conf->assign_hook) (str, true,
3654                                                                                                            PGC_S_SESSION);
3655                                                 if (newstr == NULL)
3656                                                         elog(ERROR, "failed to reset %s to \"%s\"",
3657                                                                  conf->gen.name, str);
3658                                                 else if (newstr != str)
3659                                                 {
3660                                                         /*
3661                                                          * See notes in set_config_option about casting
3662                                                          */
3663                                                         str = (char *) newstr;
3664                                                 }
3665                                         }
3666
3667                                         set_string_field(conf, conf->variable, str);
3668                                         break;
3669                                 }
3670                         case PGC_ENUM:
3671                                 {
3672                                         struct config_enum *conf = (struct config_enum *) gconf;
3673
3674                                         if (conf->assign_hook)
3675                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3676                                                                                                    PGC_S_SESSION))
3677                                                         elog(ERROR, "failed to reset %s to %s",
3678                                                                  conf->gen.name,
3679                                                                  config_enum_lookup_by_value(conf, conf->reset_val));
3680                                         *conf->variable = conf->reset_val;
3681                                         break;
3682                                 }
3683                 }
3684
3685                 gconf->source = gconf->reset_source;
3686
3687                 if (gconf->flags & GUC_REPORT)
3688                         ReportGUCOption(gconf);
3689         }
3690 }
3691
3692
3693 /*
3694  * push_old_value
3695  *              Push previous state during transactional assignment to a GUC variable.
3696  */
3697 static void
3698 push_old_value(struct config_generic * gconf, GucAction action)
3699 {
3700         GucStack   *stack;
3701
3702         /* If we're not inside a nest level, do nothing */
3703         if (GUCNestLevel == 0)
3704                 return;
3705
3706         /* Do we already have a stack entry of the current nest level? */
3707         stack = gconf->stack;
3708         if (stack && stack->nest_level >= GUCNestLevel)
3709         {
3710                 /* Yes, so adjust its state if necessary */
3711                 Assert(stack->nest_level == GUCNestLevel);
3712                 switch (action)
3713                 {
3714                         case GUC_ACTION_SET:
3715                                 /* SET overrides any prior action at same nest level */
3716                                 if (stack->state == GUC_SET_LOCAL)
3717                                 {
3718                                         /* must discard old masked value */
3719                                         discard_stack_value(gconf, &stack->masked);
3720                                 }
3721                                 stack->state = GUC_SET;
3722                                 break;
3723                         case GUC_ACTION_LOCAL:
3724                                 if (stack->state == GUC_SET)
3725                                 {
3726                                         /* SET followed by SET LOCAL, remember SET's value */
3727                                         set_stack_value(gconf, &stack->masked);
3728                                         stack->state = GUC_SET_LOCAL;
3729                                 }
3730                                 /* in all other cases, no change to stack entry */
3731                                 break;
3732                         case GUC_ACTION_SAVE:
3733                                 /* Could only have a prior SAVE of same variable */
3734                                 Assert(stack->state == GUC_SAVE);
3735                                 break;
3736                 }
3737                 Assert(guc_dirty);              /* must be set already */
3738                 return;
3739         }
3740
3741         /*
3742          * Push a new stack entry
3743          *
3744          * We keep all the stack entries in TopTransactionContext for simplicity.
3745          */
3746         stack = (GucStack *) MemoryContextAllocZero(TopTransactionContext,
3747                                                                                                 sizeof(GucStack));
3748
3749         stack->prev = gconf->stack;
3750         stack->nest_level = GUCNestLevel;
3751         switch (action)
3752         {
3753                 case GUC_ACTION_SET:
3754                         stack->state = GUC_SET;
3755                         break;
3756                 case GUC_ACTION_LOCAL:
3757                         stack->state = GUC_LOCAL;
3758                         break;
3759                 case GUC_ACTION_SAVE:
3760                         stack->state = GUC_SAVE;
3761                         break;
3762         }
3763         stack->source = gconf->source;
3764         set_stack_value(gconf, &stack->prior);
3765
3766         gconf->stack = stack;
3767
3768         /* Ensure we remember to pop at end of xact */
3769         guc_dirty = true;
3770 }
3771
3772
3773 /*
3774  * Do GUC processing at main transaction start.
3775  */
3776 void
3777 AtStart_GUC(void)
3778 {
3779         /*
3780          * The nest level should be 0 between transactions; if it isn't, somebody
3781          * didn't call AtEOXact_GUC, or called it with the wrong nestLevel.  We
3782          * throw a warning but make no other effort to clean up.
3783          */
3784         if (GUCNestLevel != 0)
3785                 elog(WARNING, "GUC nest level = %d at transaction start",
3786                          GUCNestLevel);
3787         GUCNestLevel = 1;
3788 }
3789
3790 /*
3791  * Enter a new nesting level for GUC values.  This is called at subtransaction
3792  * start and when entering a function that has proconfig settings.      NOTE that
3793  * we must not risk error here, else subtransaction start will be unhappy.
3794  */
3795 int
3796 NewGUCNestLevel(void)
3797 {
3798         return ++GUCNestLevel;
3799 }
3800
3801 /*
3802  * Do GUC processing at transaction or subtransaction commit or abort, or
3803  * when exiting a function that has proconfig settings.  (The name is thus
3804  * a bit of a misnomer; perhaps it should be ExitGUCNestLevel or some such.)
3805  * During abort, we discard all GUC settings that were applied at nesting
3806  * levels >= nestLevel.  nestLevel == 1 corresponds to the main transaction.
3807  */
3808 void
3809 AtEOXact_GUC(bool isCommit, int nestLevel)
3810 {
3811         bool            still_dirty;
3812         int                     i;
3813
3814         Assert(nestLevel > 0 && nestLevel <= GUCNestLevel);
3815
3816         /* Quick exit if nothing's changed in this transaction */
3817         if (!guc_dirty)
3818         {
3819                 GUCNestLevel = nestLevel - 1;
3820                 return;
3821         }
3822
3823         still_dirty = false;
3824         for (i = 0; i < num_guc_variables; i++)
3825         {
3826                 struct config_generic *gconf = guc_variables[i];
3827                 GucStack   *stack;
3828
3829                 /*
3830                  * Process and pop each stack entry within the nest level.      To
3831                  * simplify fmgr_security_definer(), we allow failure exit from a
3832                  * function-with-SET-options to be recovered at the surrounding
3833                  * transaction or subtransaction abort; so there could be more than
3834                  * one stack entry to pop.
3835                  */
3836                 while ((stack = gconf->stack) != NULL &&
3837                            stack->nest_level >= nestLevel)
3838                 {
3839                         GucStack   *prev = stack->prev;
3840                         bool            restorePrior = false;
3841                         bool            restoreMasked = false;
3842                         bool            changed;
3843
3844                         /*
3845                          * In this next bit, if we don't set either restorePrior or
3846                          * restoreMasked, we must "discard" any unwanted fields of the
3847                          * stack entries to avoid leaking memory.  If we do set one of
3848                          * those flags, unused fields will be cleaned up after restoring.
3849                          */
3850                         if (!isCommit)          /* if abort, always restore prior value */
3851                                 restorePrior = true;
3852                         else if (stack->state == GUC_SAVE)
3853                                 restorePrior = true;
3854                         else if (stack->nest_level == 1)
3855                         {
3856                                 /* transaction commit */
3857                                 if (stack->state == GUC_SET_LOCAL)
3858                                         restoreMasked = true;
3859                                 else if (stack->state == GUC_SET)
3860                                 {
3861                                         /* we keep the current active value */
3862                                         discard_stack_value(gconf, &stack->prior);
3863                                 }
3864                                 else    /* must be GUC_LOCAL */
3865                                         restorePrior = true;
3866                         }
3867                         else if (prev == NULL ||
3868                                          prev->nest_level < stack->nest_level - 1)
3869                         {
3870                                 /* decrement entry's level and do not pop it */
3871                                 stack->nest_level--;
3872                                 continue;
3873                         }
3874                         else
3875                         {
3876                                 /*
3877                                  * We have to merge this stack entry into prev. See README for
3878                                  * discussion of this bit.
3879                                  */
3880                                 switch (stack->state)
3881                                 {
3882                                         case GUC_SAVE:
3883                                                 Assert(false);  /* can't get here */
3884
3885                                         case GUC_SET:
3886                                                 /* next level always becomes SET */
3887                                                 discard_stack_value(gconf, &stack->prior);
3888                                                 if (prev->state == GUC_SET_LOCAL)
3889                                                         discard_stack_value(gconf, &prev->masked);
3890                                                 prev->state = GUC_SET;
3891                                                 break;
3892
3893                                         case GUC_LOCAL:
3894                                                 if (prev->state == GUC_SET)
3895                                                 {
3896                                                         /* LOCAL migrates down */
3897                                                         prev->masked = stack->prior;
3898                                                         prev->state = GUC_SET_LOCAL;
3899                                                 }
3900                                                 else
3901                                                 {
3902                                                         /* else just forget this stack level */
3903                                                         discard_stack_value(gconf, &stack->prior);
3904                                                 }
3905                                                 break;
3906
3907                                         case GUC_SET_LOCAL:
3908                                                 /* prior state at this level no longer wanted */
3909                                                 discard_stack_value(gconf, &stack->prior);
3910                                                 /* copy down the masked state */
3911                                                 if (prev->state == GUC_SET_LOCAL)
3912                                                         discard_stack_value(gconf, &prev->masked);
3913                                                 prev->masked = stack->masked;
3914                                                 prev->state = GUC_SET_LOCAL;
3915                                                 break;
3916                                 }
3917                         }
3918
3919                         changed = false;
3920
3921                         if (restorePrior || restoreMasked)
3922                         {
3923                                 /* Perform appropriate restoration of the stacked value */
3924                                 union config_var_value newvalue;
3925                                 GucSource       newsource;
3926
3927                                 if (restoreMasked)
3928                                 {
3929                                         newvalue = stack->masked;
3930                                         newsource = PGC_S_SESSION;
3931                                 }
3932                                 else
3933                                 {
3934                                         newvalue = stack->prior;
3935                                         newsource = stack->source;
3936                                 }
3937
3938                                 switch (gconf->vartype)
3939                                 {
3940                                         case PGC_BOOL:
3941                                                 {
3942                                                         struct config_bool *conf = (struct config_bool *) gconf;
3943                                                         bool            newval = newvalue.boolval;
3944
3945                                                         if (*conf->variable != newval)
3946                                                         {
3947                                                                 if (conf->assign_hook)
3948                                                                         if (!(*conf->assign_hook) (newval,
3949                                                                                                            true, PGC_S_OVERRIDE))
3950                                                                                 elog(LOG, "failed to commit %s as %d",
3951                                                                                          conf->gen.name, (int) newval);
3952                                                                 *conf->variable = newval;
3953                                                                 changed = true;
3954                                                         }
3955                                                         break;
3956                                                 }
3957                                         case PGC_INT:
3958                                                 {
3959                                                         struct config_int *conf = (struct config_int *) gconf;
3960                                                         int                     newval = newvalue.intval;
3961
3962                                                         if (*conf->variable != newval)
3963                                                         {
3964                                                                 if (conf->assign_hook)
3965                                                                         if (!(*conf->assign_hook) (newval,
3966                                                                                                            true, PGC_S_OVERRIDE))
3967                                                                                 elog(LOG, "failed to commit %s as %d",
3968                                                                                          conf->gen.name, newval);
3969                                                                 *conf->variable = newval;
3970                                                                 changed = true;
3971                                                         }
3972                                                         break;
3973                                                 }
3974                                         case PGC_REAL:
3975                                                 {
3976                                                         struct config_real *conf = (struct config_real *) gconf;
3977                                                         double          newval = newvalue.realval;
3978
3979                                                         if (*conf->variable != newval)
3980                                                         {
3981                                                                 if (conf->assign_hook)
3982                                                                         if (!(*conf->assign_hook) (newval,
3983                                                                                                            true, PGC_S_OVERRIDE))
3984                                                                                 elog(LOG, "failed to commit %s as %g",
3985                                                                                          conf->gen.name, newval);
3986                                                                 *conf->variable = newval;
3987                                                                 changed = true;
3988                                                         }
3989                                                         break;
3990                                                 }
3991                                         case PGC_STRING:
3992                                                 {
3993                                                         struct config_string *conf = (struct config_string *) gconf;
3994                                                         char       *newval = newvalue.stringval;
3995
3996                                                         if (*conf->variable != newval)
3997                                                         {
3998                                                                 if (conf->assign_hook && newval)
3999                                                                 {
4000                                                                         const char *newstr;
4001
4002                                                                         newstr = (*conf->assign_hook) (newval, true,
4003                                                                                                                          PGC_S_OVERRIDE);
4004                                                                         if (newstr == NULL)
4005                                                                                 elog(LOG, "failed to commit %s as \"%s\"",
4006                                                                                          conf->gen.name, newval);
4007                                                                         else if (newstr != newval)
4008                                                                         {
4009                                                                                 /*
4010                                                                                  * If newval should now be freed,
4011                                                                                  * it'll be taken care of below.
4012                                                                                  *
4013                                                                                  * See notes in set_config_option
4014                                                                                  * about casting
4015                                                                                  */
4016                                                                                 newval = (char *) newstr;
4017                                                                         }
4018                                                                 }
4019
4020                                                                 set_string_field(conf, conf->variable, newval);
4021                                                                 changed = true;
4022                                                         }
4023
4024                                                         /*
4025                                                          * Release stacked values if not used anymore. We
4026                                                          * could use discard_stack_value() here, but since
4027                                                          * we have type-specific code anyway, might as
4028                                                          * well inline it.
4029                                                          */
4030                                                         set_string_field(conf, &stack->prior.stringval, NULL);
4031                                                         set_string_field(conf, &stack->masked.stringval, NULL);
4032                                                         break;
4033                                                 }
4034                                         case PGC_ENUM:
4035                                                 {
4036                                                         struct config_enum *conf = (struct config_enum *) gconf;
4037                                                         int                     newval = newvalue.enumval;
4038
4039                                                         if (*conf->variable != newval)
4040                                                         {
4041                                                                 if (conf->assign_hook)
4042                                                                         if (!(*conf->assign_hook) (newval,
4043                                                                                                            true, PGC_S_OVERRIDE))
4044                                                                                 elog(LOG, "failed to commit %s as %s",
4045                                                                                          conf->gen.name,
4046                                                                                          config_enum_lookup_by_value(conf, newval));
4047                                                                 *conf->variable = newval;
4048                                                                 changed = true;
4049                                                         }
4050                                                         break;
4051                                                 }
4052                                 }
4053
4054                                 gconf->source = newsource;
4055                         }
4056
4057                         /* Finish popping the state stack */
4058                         gconf->stack = prev;
4059                         pfree(stack);
4060
4061                         /* Report new value if we changed it */
4062                         if (changed && (gconf->flags & GUC_REPORT))
4063                                 ReportGUCOption(gconf);
4064                 }                                               /* end of stack-popping loop */
4065
4066                 if (stack != NULL)
4067                         still_dirty = true;
4068         }
4069
4070         /* If there are no remaining stack entries, we can reset guc_dirty */
4071         guc_dirty = still_dirty;
4072
4073         /* Update nesting level */
4074         GUCNestLevel = nestLevel - 1;
4075 }
4076
4077
4078 /*
4079  * Start up automatic reporting of changes to variables marked GUC_REPORT.
4080  * This is executed at completion of backend startup.
4081  */
4082 void
4083 BeginReportingGUCOptions(void)
4084 {
4085         int                     i;
4086
4087         /*
4088          * Don't do anything unless talking to an interactive frontend of protocol
4089          * 3.0 or later.
4090          */
4091         if (whereToSendOutput != DestRemote ||
4092                 PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
4093                 return;
4094
4095         reporting_enabled = true;
4096
4097         /* Transmit initial values of interesting variables */
4098         for (i = 0; i < num_guc_variables; i++)
4099         {
4100                 struct config_generic *conf = guc_variables[i];
4101
4102                 if (conf->flags & GUC_REPORT)
4103                         ReportGUCOption(conf);
4104         }
4105 }
4106
4107 /*
4108  * ReportGUCOption: if appropriate, transmit option value to frontend
4109  */
4110 static void
4111 ReportGUCOption(struct config_generic * record)
4112 {
4113         if (reporting_enabled && (record->flags & GUC_REPORT))
4114         {
4115                 char       *val = _ShowOption(record, false);
4116                 StringInfoData msgbuf;
4117
4118                 pq_beginmessage(&msgbuf, 'S');
4119                 pq_sendstring(&msgbuf, record->name);
4120                 pq_sendstring(&msgbuf, val);
4121                 pq_endmessage(&msgbuf);
4122
4123                 pfree(val);
4124         }
4125 }
4126
4127 /*
4128  * Try to parse value as an integer.  The accepted formats are the
4129  * usual decimal, octal, or hexadecimal formats, optionally followed by
4130  * a unit name if "flags" indicates a unit is allowed.
4131  *
4132  * If the string parses okay, return true, else false.
4133  * If okay and result is not NULL, return the value in *result.
4134  * If not okay and hintmsg is not NULL, *hintmsg is set to a suitable
4135  *      HINT message, or NULL if no hint provided.
4136  */
4137 bool
4138 parse_int(const char *value, int *result, int flags, const char **hintmsg)
4139 {
4140         int64           val;
4141         char       *endptr;
4142
4143         /* To suppress compiler warnings, always set output params */
4144         if (result)
4145                 *result = 0;
4146         if (hintmsg)
4147                 *hintmsg = NULL;
4148
4149         /* We assume here that int64 is at least as wide as long */
4150         errno = 0;
4151         val = strtol(value, &endptr, 0);
4152
4153         if (endptr == value)
4154                 return false;                   /* no HINT for integer syntax error */
4155
4156         if (errno == ERANGE || val != (int64) ((int32) val))
4157         {
4158                 if (hintmsg)
4159                         *hintmsg = gettext_noop("Value exceeds integer range.");
4160                 return false;
4161         }
4162
4163         /* allow whitespace between integer and unit */
4164         while (isspace((unsigned char) *endptr))
4165                 endptr++;
4166
4167         /* Handle possible unit */
4168         if (*endptr != '\0')
4169         {
4170                 /*
4171                  * Note: the multiple-switch coding technique here is a bit tedious,
4172                  * but seems necessary to avoid intermediate-value overflows.
4173                  *
4174                  * If INT64_IS_BUSTED (ie, it's really int32) we will fail to detect
4175                  * overflow due to units conversion, but there are few enough such
4176                  * machines that it does not seem worth trying to be smarter.
4177                  */
4178                 if (flags & GUC_UNIT_MEMORY)
4179                 {
4180                         /* Set hint for use if no match or trailing garbage */
4181                         if (hintmsg)
4182                                 *hintmsg = gettext_noop("Valid units for this parameter are \"kB\", \"MB\", and \"GB\".");
4183
4184 #if BLCKSZ < 1024 || BLCKSZ > (1024*1024)
4185 #error BLCKSZ must be between 1KB and 1MB
4186 #endif
4187 #if XLOG_BLCKSZ < 1024 || XLOG_BLCKSZ > (1024*1024)
4188 #error XLOG_BLCKSZ must be between 1KB and 1MB
4189 #endif
4190
4191                         if (strncmp(endptr, "kB", 2) == 0)
4192                         {
4193                                 endptr += 2;
4194                                 switch (flags & GUC_UNIT_MEMORY)
4195                                 {
4196                                         case GUC_UNIT_BLOCKS:
4197                                                 val /= (BLCKSZ / 1024);
4198                                                 break;
4199                                         case GUC_UNIT_XBLOCKS:
4200                                                 val /= (XLOG_BLCKSZ / 1024);
4201                                                 break;
4202                                 }
4203                         }
4204                         else if (strncmp(endptr, "MB", 2) == 0)
4205                         {
4206                                 endptr += 2;
4207                                 switch (flags & GUC_UNIT_MEMORY)
4208                                 {
4209                                         case GUC_UNIT_KB:
4210                                                 val *= KB_PER_MB;
4211                                                 break;
4212                                         case GUC_UNIT_BLOCKS:
4213                                                 val *= KB_PER_MB / (BLCKSZ / 1024);
4214                                                 break;
4215                                         case GUC_UNIT_XBLOCKS:
4216                                                 val *= KB_PER_MB / (XLOG_BLCKSZ / 1024);
4217                                                 break;
4218                                 }
4219                         }
4220                         else if (strncmp(endptr, "GB", 2) == 0)
4221                         {
4222                                 endptr += 2;
4223                                 switch (flags & GUC_UNIT_MEMORY)
4224                                 {
4225                                         case GUC_UNIT_KB:
4226                                                 val *= KB_PER_GB;
4227                                                 break;
4228                                         case GUC_UNIT_BLOCKS:
4229                                                 val *= KB_PER_GB / (BLCKSZ / 1024);
4230                                                 break;
4231                                         case GUC_UNIT_XBLOCKS:
4232                                                 val *= KB_PER_GB / (XLOG_BLCKSZ / 1024);
4233                                                 break;
4234                                 }
4235                         }
4236                 }
4237                 else if (flags & GUC_UNIT_TIME)
4238                 {
4239                         /* Set hint for use if no match or trailing garbage */
4240                         if (hintmsg)
4241                                 *hintmsg = gettext_noop("Valid units for this parameter are \"ms\", \"s\", \"min\", \"h\", and \"d\".");
4242
4243                         if (strncmp(endptr, "ms", 2) == 0)
4244                         {
4245                                 endptr += 2;
4246                                 switch (flags & GUC_UNIT_TIME)
4247                                 {
4248                                         case GUC_UNIT_S:
4249                                                 val /= MS_PER_S;
4250                                                 break;
4251                                         case GUC_UNIT_MIN:
4252                                                 val /= MS_PER_MIN;
4253                                                 break;
4254                                 }
4255                         }
4256                         else if (strncmp(endptr, "s", 1) == 0)
4257                         {
4258                                 endptr += 1;
4259                                 switch (flags & GUC_UNIT_TIME)
4260                                 {
4261                                         case GUC_UNIT_MS:
4262                                                 val *= MS_PER_S;
4263                                                 break;
4264                                         case GUC_UNIT_MIN:
4265                                                 val /= S_PER_MIN;
4266                                                 break;
4267                                 }
4268                         }
4269                         else if (strncmp(endptr, "min", 3) == 0)
4270                         {
4271                                 endptr += 3;
4272                                 switch (flags & GUC_UNIT_TIME)
4273                                 {
4274                                         case GUC_UNIT_MS:
4275                                                 val *= MS_PER_MIN;
4276                                                 break;
4277                                         case GUC_UNIT_S:
4278                                                 val *= S_PER_MIN;
4279                                                 break;
4280                                 }
4281                         }
4282                         else if (strncmp(endptr, "h", 1) == 0)
4283                         {
4284                                 endptr += 1;
4285                                 switch (flags & GUC_UNIT_TIME)
4286                                 {
4287                                         case GUC_UNIT_MS:
4288                                                 val *= MS_PER_H;
4289                                                 break;
4290                                         case GUC_UNIT_S:
4291                                                 val *= S_PER_H;
4292                                                 break;
4293                                         case GUC_UNIT_MIN:
4294                                                 val *= MIN_PER_H;
4295                                                 break;
4296                                 }
4297                         }
4298                         else if (strncmp(endptr, "d", 1) == 0)
4299                         {
4300                                 endptr += 1;
4301                                 switch (flags & GUC_UNIT_TIME)
4302                                 {
4303                                         case GUC_UNIT_MS:
4304                                                 val *= MS_PER_D;
4305                                                 break;
4306                                         case GUC_UNIT_S:
4307                                                 val *= S_PER_D;
4308                                                 break;
4309                                         case GUC_UNIT_MIN:
4310                                                 val *= MIN_PER_D;
4311                                                 break;
4312                                 }
4313                         }
4314                 }
4315
4316                 /* allow whitespace after unit */
4317                 while (isspace((unsigned char) *endptr))
4318                         endptr++;
4319
4320                 if (*endptr != '\0')
4321                         return false;           /* appropriate hint, if any, already set */
4322
4323                 /* Check for overflow due to units conversion */
4324                 if (val != (int64) ((int32) val))
4325                 {
4326                         if (hintmsg)
4327                                 *hintmsg = gettext_noop("Value exceeds integer range.");
4328                         return false;
4329                 }
4330         }
4331
4332         if (result)
4333                 *result = (int) val;
4334         return true;
4335 }
4336
4337
4338
4339 /*
4340  * Try to parse value as a floating point number in the usual format.
4341  * If the string parses okay, return true, else false.
4342  * If okay and result is not NULL, return the value in *result.
4343  */
4344 bool
4345 parse_real(const char *value, double *result)
4346 {
4347         double          val;
4348         char       *endptr;
4349
4350         if (result)
4351                 *result = 0;                    /* suppress compiler warning */
4352
4353         errno = 0;
4354         val = strtod(value, &endptr);
4355         if (endptr == value || errno == ERANGE)
4356                 return false;
4357
4358         /* allow whitespace after number */
4359         while (isspace((unsigned char) *endptr))
4360                 endptr++;
4361         if (*endptr != '\0')
4362                 return false;
4363
4364         if (result)
4365                 *result = val;
4366         return true;
4367 }
4368
4369
4370 /*
4371  * Lookup the name for an enum option with the selected value.
4372  * Should only ever be called with known-valid values, so throws
4373  * an elog(ERROR) if the enum option is not found.
4374  *
4375  * The returned string is a pointer to static data and not
4376  * allocated for modification.
4377  */
4378 const char *
4379 config_enum_lookup_by_value(struct config_enum * record, int val)
4380 {
4381         const struct config_enum_entry *entry;
4382
4383         for (entry = record->options; entry && entry->name; entry++)
4384         {
4385                 if (entry->val == val)
4386                         return entry->name;
4387         }
4388
4389         elog(ERROR, "could not find enum option %d for %s",
4390                  val, record->gen.name);
4391         return NULL;                            /* silence compiler */
4392 }
4393
4394
4395 /*
4396  * Lookup the value for an enum option with the selected name
4397  * (case-insensitive).
4398  * If the enum option is found, sets the retval value and returns
4399  * true. If it's not found, return FALSE and retval is set to 0.
4400  */
4401 bool
4402 config_enum_lookup_by_name(struct config_enum * record, const char *value,
4403                                                    int *retval)
4404 {
4405         const struct config_enum_entry *entry;
4406
4407         for (entry = record->options; entry && entry->name; entry++)
4408         {
4409                 if (pg_strcasecmp(value, entry->name) == 0)
4410                 {
4411                         *retval = entry->val;
4412                         return TRUE;
4413                 }
4414         }
4415
4416         *retval = 0;
4417         return FALSE;
4418 }
4419
4420
4421 /*
4422  * Return a list of all available options for an enum, excluding
4423  * hidden ones, separated by the given separator.
4424  * If prefix is non-NULL, it is added before the first enum value.
4425  * If suffix is non-NULL, it is added to the end of the string.
4426  */
4427 static char *
4428 config_enum_get_options(struct config_enum * record, const char *prefix,
4429                                                 const char *suffix, const char *separator)
4430 {
4431         const struct config_enum_entry *entry;
4432         StringInfoData retstr;
4433         int                     seplen;
4434
4435         initStringInfo(&retstr);
4436         appendStringInfoString(&retstr, prefix);
4437
4438         seplen = strlen(separator);
4439         for (entry = record->options; entry && entry->name; entry++)
4440         {
4441                 if (!entry->hidden)
4442                 {
4443                         appendStringInfoString(&retstr, entry->name);
4444                         appendBinaryStringInfo(&retstr, separator, seplen);
4445                 }
4446         }
4447
4448         /*
4449          * All the entries may have been hidden, leaving the string empty if no
4450          * prefix was given. This indicates a broken GUC setup, since there is no
4451          * use for an enum without any values, so we just check to make sure we
4452          * don't write to invalid memory instead of actually trying to do
4453          * something smart with it.
4454          */
4455         if (retstr.len >= seplen)
4456         {
4457                 /* Replace final separator */
4458                 retstr.data[retstr.len - seplen] = '\0';
4459                 retstr.len -= seplen;
4460         }
4461
4462         appendStringInfoString(&retstr, suffix);
4463
4464         return retstr.data;
4465 }
4466
4467 /*
4468  * Call a GucStringAssignHook function, being careful to free the
4469  * "newval" string if the hook ereports.
4470  *
4471  * This is split out of set_config_option just to avoid the "volatile"
4472  * qualifiers that would otherwise have to be plastered all over.
4473  */
4474 static const char *
4475 call_string_assign_hook(GucStringAssignHook assign_hook,
4476                                                 char *newval, bool doit, GucSource source)
4477 {
4478         const char *result;
4479
4480         PG_TRY();
4481         {
4482                 result = (*assign_hook) (newval, doit, source);
4483         }
4484         PG_CATCH();
4485         {
4486                 free(newval);
4487                 PG_RE_THROW();
4488         }
4489         PG_END_TRY();
4490
4491         return result;
4492 }
4493
4494
4495 /*
4496  * Sets option `name' to given value. The value should be a string
4497  * which is going to be parsed and converted to the appropriate data
4498  * type.  The context and source parameters indicate in which context this
4499  * function is being called so it can apply the access restrictions
4500  * properly.
4501  *
4502  * If value is NULL, set the option to its default value (normally the
4503  * reset_val, but if source == PGC_S_DEFAULT we instead use the boot_val).
4504  *
4505  * action indicates whether to set the value globally in the session, locally
4506  * to the current top transaction, or just for the duration of a function call.
4507  *
4508  * If changeVal is false then don't really set the option but do all
4509  * the checks to see if it would work.
4510  *
4511  * If there is an error (non-existing option, invalid value) then an
4512  * ereport(ERROR) is thrown *unless* this is called in a context where we
4513  * don't want to ereport (currently, startup or SIGHUP config file reread).
4514  * In that case we write a suitable error message via ereport(LOG) and
4515  * return false. This is working around the deficiencies in the ereport
4516  * mechanism, so don't blame me.  In all other cases, the function
4517  * returns true, including cases where the input is valid but we chose
4518  * not to apply it because of context or source-priority considerations.
4519  *
4520  * See also SetConfigOption for an external interface.
4521  */
4522 bool
4523 set_config_option(const char *name, const char *value,
4524                                   GucContext context, GucSource source,
4525                                   GucAction action, bool changeVal)
4526 {
4527         struct config_generic *record;
4528         int                     elevel;
4529         bool            makeDefault;
4530
4531         if (context == PGC_SIGHUP || source == PGC_S_DEFAULT)
4532         {
4533                 /*
4534                  * To avoid cluttering the log, only the postmaster bleats loudly
4535                  * about problems with the config file.
4536                  */
4537                 elevel = IsUnderPostmaster ? DEBUG3 : LOG;
4538         }
4539         else if (source == PGC_S_DATABASE || source == PGC_S_USER)
4540                 elevel = WARNING;
4541         else
4542                 elevel = ERROR;
4543
4544         record = find_option(name, true, elevel);
4545         if (record == NULL)
4546         {
4547                 ereport(elevel,
4548                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
4549                            errmsg("unrecognized configuration parameter \"%s\"", name)));
4550                 return false;
4551         }
4552
4553         /*
4554          * If source is postgresql.conf, mark the found record with
4555          * GUC_IS_IN_FILE. This is for the convenience of ProcessConfigFile.  Note
4556          * that we do it even if changeVal is false, since ProcessConfigFile wants
4557          * the marking to occur during its testing pass.
4558          */
4559         if (source == PGC_S_FILE)
4560                 record->status |= GUC_IS_IN_FILE;
4561
4562         /*
4563          * Check if the option can be set at this time. See guc.h for the precise
4564          * rules. Note that we don't want to throw errors if we're in the SIGHUP
4565          * context. In that case we just ignore the attempt and return true.
4566          */
4567         switch (record->context)
4568         {
4569                 case PGC_INTERNAL:
4570                         if (context == PGC_SIGHUP)
4571                                 return true;
4572                         if (context != PGC_INTERNAL)
4573                         {
4574                                 ereport(elevel,
4575                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4576                                                  errmsg("parameter \"%s\" cannot be changed",
4577                                                                 name)));
4578                                 return false;
4579                         }
4580                         break;
4581                 case PGC_POSTMASTER:
4582                         if (context == PGC_SIGHUP)
4583                         {
4584                                 /*
4585                                  * We are reading a PGC_POSTMASTER var from postgresql.conf.
4586                                  * We can't change the setting, so give a warning if the DBA
4587                                  * tries to change it.  (Throwing an error would be more
4588                                  * consistent, but seems overly rigid.)
4589                                  */
4590                                 if (changeVal && !is_newvalue_equal(record, value))
4591                                         ereport(elevel,
4592                                                         (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4593                                            errmsg("attempted change of parameter \"%s\" ignored",
4594                                                           name),
4595                                                          errdetail("This parameter cannot be changed after server start.")));
4596                                 return true;
4597                         }
4598                         if (context != PGC_POSTMASTER)
4599                         {
4600                                 ereport(elevel,
4601                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4602                                            errmsg("attempted change of parameter \"%s\" ignored",
4603                                                           name),
4604                                                  errdetail("This parameter cannot be changed after server start.")));
4605                                 return false;
4606                         }
4607                         break;
4608                 case PGC_SIGHUP:
4609                         if (context != PGC_SIGHUP && context != PGC_POSTMASTER)
4610                         {
4611                                 ereport(elevel,
4612                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4613                                                  errmsg("parameter \"%s\" cannot be changed now",
4614                                                                 name)));
4615                                 return false;
4616                         }
4617
4618                         /*
4619                          * Hmm, the idea of the SIGHUP context is "ought to be global, but
4620                          * can be changed after postmaster start". But there's nothing
4621                          * that prevents a crafty administrator from sending SIGHUP
4622                          * signals to individual backends only.
4623                          */
4624                         break;
4625                 case PGC_BACKEND:
4626                         if (context == PGC_SIGHUP)
4627                         {
4628                                 /*
4629                                  * If a PGC_BACKEND parameter is changed in the config file,
4630                                  * we want to accept the new value in the postmaster (whence
4631                                  * it will propagate to subsequently-started backends), but
4632                                  * ignore it in existing backends.      This is a tad klugy, but
4633                                  * necessary because we don't re-read the config file during
4634                                  * backend start.
4635                                  */
4636                                 if (IsUnderPostmaster)
4637                                         return true;
4638                         }
4639                         else if (context != PGC_POSTMASTER && context != PGC_BACKEND &&
4640                                          source != PGC_S_CLIENT)
4641                         {
4642                                 ereport(elevel,
4643                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4644                                                  errmsg("parameter \"%s\" cannot be set after connection start",
4645                                                                 name)));
4646                                 return false;
4647                         }
4648                         break;
4649                 case PGC_SUSET:
4650                         if (context == PGC_USERSET || context == PGC_BACKEND)
4651                         {
4652                                 ereport(elevel,
4653                                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
4654                                                  errmsg("permission denied to set parameter \"%s\"",
4655                                                                 name)));
4656                                 return false;
4657                         }
4658                         break;
4659                 case PGC_USERSET:
4660                         /* always okay */
4661                         break;
4662         }
4663
4664         /*
4665          * Should we set reset/stacked values?  (If so, the behavior is not
4666          * transactional.)      This is done either when we get a default value from
4667          * the database's/user's/client's default settings or when we reset a
4668          * value to its default.
4669          */
4670         makeDefault = changeVal && (source <= PGC_S_OVERRIDE) &&
4671                 ((value != NULL) || source == PGC_S_DEFAULT);
4672
4673         /*
4674          * Ignore attempted set if overridden by previously processed setting.
4675          * However, if changeVal is false then plow ahead anyway since we are
4676          * trying to find out if the value is potentially good, not actually use
4677          * it. Also keep going if makeDefault is true, since we may want to set
4678          * the reset/stacked values even if we can't set the variable itself.
4679          */
4680         if (record->source > source)
4681         {
4682                 if (changeVal && !makeDefault)
4683                 {
4684                         elog(DEBUG3, "\"%s\": setting ignored because previous source is higher priority",
4685                                  name);
4686                         return true;
4687                 }
4688                 changeVal = false;
4689         }
4690
4691         /*
4692          * Evaluate value and set variable.
4693          */
4694         switch (record->vartype)
4695         {
4696                 case PGC_BOOL:
4697                         {
4698                                 struct config_bool *conf = (struct config_bool *) record;
4699                                 bool            newval;
4700
4701                                 if (value)
4702                                 {
4703                                         if (!parse_bool(value, &newval))
4704                                         {
4705                                                 ereport(elevel,
4706                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4707                                                   errmsg("parameter \"%s\" requires a Boolean value",
4708                                                                  name)));
4709                                                 return false;
4710                                         }
4711                                 }
4712                                 else if (source == PGC_S_DEFAULT)
4713                                         newval = conf->boot_val;
4714                                 else
4715                                 {
4716                                         newval = conf->reset_val;
4717                                         source = conf->gen.reset_source;
4718                                 }
4719
4720                                 /* Save old value to support transaction abort */
4721                                 if (changeVal && !makeDefault)
4722                                         push_old_value(&conf->gen, action);
4723
4724                                 if (conf->assign_hook)
4725                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4726                                         {
4727                                                 ereport(elevel,
4728                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4729                                                          errmsg("invalid value for parameter \"%s\": %d",
4730                                                                         name, (int) newval)));
4731                                                 return false;
4732                                         }
4733
4734                                 if (changeVal)
4735                                 {
4736                                         *conf->variable = newval;
4737                                         conf->gen.source = source;
4738                                 }
4739                                 if (makeDefault)
4740                                 {
4741                                         GucStack   *stack;
4742
4743                                         if (conf->gen.reset_source <= source)
4744                                         {
4745                                                 conf->reset_val = newval;
4746                                                 conf->gen.reset_source = source;
4747                                         }
4748                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4749                                         {
4750                                                 if (stack->source <= source)
4751                                                 {
4752                                                         stack->prior.boolval = newval;
4753                                                         stack->source = source;
4754                                                 }
4755                                         }
4756                                 }
4757                                 break;
4758                         }
4759
4760                 case PGC_INT:
4761                         {
4762                                 struct config_int *conf = (struct config_int *) record;
4763                                 int                     newval;
4764
4765                                 if (value)
4766                                 {
4767                                         const char *hintmsg;
4768
4769                                         if (!parse_int(value, &newval, conf->gen.flags, &hintmsg))
4770                                         {
4771                                                 ereport(elevel,
4772                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4773                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
4774                                                                 name, value),
4775                                                                  hintmsg ? errhint("%s", _(hintmsg)) : 0));
4776                                                 return false;
4777                                         }
4778                                         if (newval < conf->min || newval > conf->max)
4779                                         {
4780                                                 ereport(elevel,
4781                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4782                                                                  errmsg("%d is outside the valid range for parameter \"%s\" (%d .. %d)",
4783                                                                                 newval, name, conf->min, conf->max)));
4784                                                 return false;
4785                                         }
4786                                 }
4787                                 else if (source == PGC_S_DEFAULT)
4788                                         newval = conf->boot_val;
4789                                 else
4790                                 {
4791                                         newval = conf->reset_val;
4792                                         source = conf->gen.reset_source;
4793                                 }
4794
4795                                 /* Save old value to support transaction abort */
4796                                 if (changeVal && !makeDefault)
4797                                         push_old_value(&conf->gen, action);
4798
4799                                 if (conf->assign_hook)
4800                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4801                                         {
4802                                                 ereport(elevel,
4803                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4804                                                          errmsg("invalid value for parameter \"%s\": %d",
4805                                                                         name, newval)));
4806                                                 return false;
4807                                         }
4808
4809                                 if (changeVal)
4810                                 {
4811                                         *conf->variable = newval;
4812                                         conf->gen.source = source;
4813                                 }
4814                                 if (makeDefault)
4815                                 {
4816                                         GucStack   *stack;
4817
4818                                         if (conf->gen.reset_source <= source)
4819                                         {
4820                                                 conf->reset_val = newval;
4821                                                 conf->gen.reset_source = source;
4822                                         }
4823                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4824                                         {
4825                                                 if (stack->source <= source)
4826                                                 {
4827                                                         stack->prior.intval = newval;
4828                                                         stack->source = source;
4829                                                 }
4830                                         }
4831                                 }
4832                                 break;
4833                         }
4834
4835                 case PGC_REAL:
4836                         {
4837                                 struct config_real *conf = (struct config_real *) record;
4838                                 double          newval;
4839
4840                                 if (value)
4841                                 {
4842                                         if (!parse_real(value, &newval))
4843                                         {
4844                                                 ereport(elevel,
4845                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4846                                                   errmsg("parameter \"%s\" requires a numeric value",
4847                                                                  name)));
4848                                                 return false;
4849                                         }
4850                                         if (newval < conf->min || newval > conf->max)
4851                                         {
4852                                                 ereport(elevel,
4853                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4854                                                                  errmsg("%g is outside the valid range for parameter \"%s\" (%g .. %g)",
4855                                                                                 newval, name, conf->min, conf->max)));
4856                                                 return false;
4857                                         }
4858                                 }
4859                                 else if (source == PGC_S_DEFAULT)
4860                                         newval = conf->boot_val;
4861                                 else
4862                                 {
4863                                         newval = conf->reset_val;
4864                                         source = conf->gen.reset_source;
4865                                 }
4866
4867                                 /* Save old value to support transaction abort */
4868                                 if (changeVal && !makeDefault)
4869                                         push_old_value(&conf->gen, action);
4870
4871                                 if (conf->assign_hook)
4872                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4873                                         {
4874                                                 ereport(elevel,
4875                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4876                                                          errmsg("invalid value for parameter \"%s\": %g",
4877                                                                         name, newval)));
4878                                                 return false;
4879                                         }
4880
4881                                 if (changeVal)
4882                                 {
4883                                         *conf->variable = newval;
4884                                         conf->gen.source = source;
4885                                 }
4886                                 if (makeDefault)
4887                                 {
4888                                         GucStack   *stack;
4889
4890                                         if (conf->gen.reset_source <= source)
4891                                         {
4892                                                 conf->reset_val = newval;
4893                                                 conf->gen.reset_source = source;
4894                                         }
4895                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4896                                         {
4897                                                 if (stack->source <= source)
4898                                                 {
4899                                                         stack->prior.realval = newval;
4900                                                         stack->source = source;
4901                                                 }
4902                                         }
4903                                 }
4904                                 break;
4905                         }
4906
4907                 case PGC_STRING:
4908                         {
4909                                 struct config_string *conf = (struct config_string *) record;
4910                                 char       *newval;
4911
4912                                 if (value)
4913                                 {
4914                                         newval = guc_strdup(elevel, value);
4915                                         if (newval == NULL)
4916                                                 return false;
4917
4918                                         /*
4919                                          * The only sort of "parsing" check we need to do is apply
4920                                          * truncation if GUC_IS_NAME.
4921                                          */
4922                                         if (conf->gen.flags & GUC_IS_NAME)
4923                                                 truncate_identifier(newval, strlen(newval), true);
4924                                 }
4925                                 else if (source == PGC_S_DEFAULT)
4926                                 {
4927                                         if (conf->boot_val == NULL)
4928                                                 newval = NULL;
4929                                         else
4930                                         {
4931                                                 newval = guc_strdup(elevel, conf->boot_val);
4932                                                 if (newval == NULL)
4933                                                         return false;
4934                                         }
4935                                 }
4936                                 else
4937                                 {
4938                                         /*
4939                                          * We could possibly avoid strdup here, but easier to make
4940                                          * this case work the same as the normal assignment case;
4941                                          * note the possible free of newval below.
4942                                          */
4943                                         if (conf->reset_val == NULL)
4944                                                 newval = NULL;
4945                                         else
4946                                         {
4947                                                 newval = guc_strdup(elevel, conf->reset_val);
4948                                                 if (newval == NULL)
4949                                                         return false;
4950                                         }
4951                                         source = conf->gen.reset_source;
4952                                 }
4953
4954                                 /* Save old value to support transaction abort */
4955                                 if (changeVal && !makeDefault)
4956                                         push_old_value(&conf->gen, action);
4957
4958                                 if (conf->assign_hook && newval)
4959                                 {
4960                                         const char *hookresult;
4961
4962                                         /*
4963                                          * If the hook ereports, we have to make sure we free
4964                                          * newval, else it will be a permanent memory leak.
4965                                          */
4966                                         hookresult = call_string_assign_hook(conf->assign_hook,
4967                                                                                                                  newval,
4968                                                                                                                  changeVal,
4969                                                                                                                  source);
4970                                         if (hookresult == NULL)
4971                                         {
4972                                                 free(newval);
4973                                                 ereport(elevel,
4974                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4975                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
4976                                                                 name, value ? value : "")));
4977                                                 return false;
4978                                         }
4979                                         else if (hookresult != newval)
4980                                         {
4981                                                 free(newval);
4982
4983                                                 /*
4984                                                  * Having to cast away const here is annoying, but the
4985                                                  * alternative is to declare assign_hooks as returning
4986                                                  * char*, which would mean they'd have to cast away
4987                                                  * const, or as both taking and returning char*, which
4988                                                  * doesn't seem attractive either --- we don't want
4989                                                  * them to scribble on the passed str.
4990                                                  */
4991                                                 newval = (char *) hookresult;
4992                                         }
4993                                 }
4994
4995                                 if (changeVal)
4996                                 {
4997                                         set_string_field(conf, conf->variable, newval);
4998                                         conf->gen.source = source;
4999                                 }
5000                                 if (makeDefault)
5001                                 {
5002                                         GucStack   *stack;
5003
5004                                         if (conf->gen.reset_source <= source)
5005                                         {
5006                                                 set_string_field(conf, &conf->reset_val, newval);
5007                                                 conf->gen.reset_source = source;
5008                                         }
5009                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
5010                                         {
5011                                                 if (stack->source <= source)
5012                                                 {
5013                                                         set_string_field(conf, &stack->prior.stringval,
5014                                                                                          newval);
5015                                                         stack->source = source;
5016                                                 }
5017                                         }
5018                                 }
5019                                 /* Perhaps we didn't install newval anywhere */
5020                                 if (newval && !string_field_used(conf, newval))
5021                                         free(newval);
5022                                 break;
5023                         }
5024                 case PGC_ENUM:
5025                         {
5026                                 struct config_enum *conf = (struct config_enum *) record;
5027                                 int                     newval;
5028
5029                                 if (value)
5030                                 {
5031                                         if (!config_enum_lookup_by_name(conf, value, &newval))
5032                                         {
5033                                                 char       *hintmsg;
5034
5035                                                 hintmsg = config_enum_get_options(conf,
5036                                                                                                                 "Available values: ",
5037                                                                                                                   ".", ", ");
5038
5039                                                 ereport(elevel,
5040                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5041                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
5042                                                                 name, value),
5043                                                                  hintmsg ? errhint("%s", _(hintmsg)) : 0));
5044
5045                                                 if (hintmsg)
5046                                                         pfree(hintmsg);
5047                                                 return false;
5048                                         }
5049                                 }
5050                                 else if (source == PGC_S_DEFAULT)
5051                                         newval = conf->boot_val;
5052                                 else
5053                                 {
5054                                         newval = conf->reset_val;
5055                                         source = conf->gen.reset_source;
5056                                 }
5057
5058                                 /* Save old value to support transaction abort */
5059                                 if (changeVal && !makeDefault)
5060                                         push_old_value(&conf->gen, action);
5061
5062                                 if (conf->assign_hook)
5063                                         if (!(*conf->assign_hook) (newval, changeVal, source))
5064                                         {
5065                                                 ereport(elevel,
5066                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5067                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
5068                                                                 name,
5069                                                                 config_enum_lookup_by_value(conf, newval))));
5070                                                 return false;
5071                                         }
5072
5073                                 if (changeVal)
5074                                 {
5075                                         *conf->variable = newval;
5076                                         conf->gen.source = source;
5077                                 }
5078                                 if (makeDefault)
5079                                 {
5080                                         GucStack   *stack;
5081
5082                                         if (conf->gen.reset_source <= source)
5083                                         {
5084                                                 conf->reset_val = newval;
5085                                                 conf->gen.reset_source = source;
5086                                         }
5087                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
5088                                         {
5089                                                 if (stack->source <= source)
5090                                                 {
5091                                                         stack->prior.enumval = newval;
5092                                                         stack->source = source;
5093                                                 }
5094                                         }
5095                                 }
5096                                 break;
5097                         }
5098         }
5099
5100         if (changeVal && (record->flags & GUC_REPORT))
5101                 ReportGUCOption(record);
5102
5103         return true;
5104 }
5105
5106
5107 /*
5108  * Set the fields for source file and line number the setting came from.
5109  */
5110 static void
5111 set_config_sourcefile(const char *name, char *sourcefile, int sourceline)
5112 {
5113         struct config_generic *record;
5114         int                     elevel;
5115
5116         /*
5117          * To avoid cluttering the log, only the postmaster bleats loudly about
5118          * problems with the config file.
5119          */
5120         elevel = IsUnderPostmaster ? DEBUG3 : LOG;
5121
5122         record = find_option(name, true, elevel);
5123         /* should not happen */
5124         if (record == NULL)
5125                 elog(ERROR, "unrecognized configuration parameter \"%s\"", name);
5126
5127         sourcefile = guc_strdup(elevel, sourcefile);
5128         if (record->sourcefile)
5129                 free(record->sourcefile);
5130         record->sourcefile = sourcefile;
5131         record->sourceline = sourceline;
5132 }
5133
5134 /*
5135  * Set a config option to the given value. See also set_config_option,
5136  * this is just the wrapper to be called from outside GUC.      NB: this
5137  * is used only for non-transactional operations.
5138  *
5139  * Note: there is no support here for setting source file/line, as it
5140  * is currently not needed.
5141  */
5142 void
5143 SetConfigOption(const char *name, const char *value,
5144                                 GucContext context, GucSource source)
5145 {
5146         (void) set_config_option(name, value, context, source,
5147                                                          GUC_ACTION_SET, true);
5148 }
5149
5150
5151
5152 /*
5153  * Fetch the current value of the option `name'. If the option doesn't exist,
5154  * throw an ereport and don't return.
5155  *
5156  * The string is *not* allocated for modification and is really only
5157  * valid until the next call to configuration related functions.
5158  */
5159 const char *
5160 GetConfigOption(const char *name)
5161 {
5162         struct config_generic *record;
5163         static char buffer[256];
5164
5165         record = find_option(name, false, ERROR);
5166         if (record == NULL)
5167                 ereport(ERROR,
5168                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5169                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5170         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
5171                 ereport(ERROR,
5172                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5173                                  errmsg("must be superuser to examine \"%s\"", name)));
5174
5175         switch (record->vartype)
5176         {
5177                 case PGC_BOOL:
5178                         return *((struct config_bool *) record)->variable ? "on" : "off";
5179
5180                 case PGC_INT:
5181                         snprintf(buffer, sizeof(buffer), "%d",
5182                                          *((struct config_int *) record)->variable);
5183                         return buffer;
5184
5185                 case PGC_REAL:
5186                         snprintf(buffer, sizeof(buffer), "%g",
5187                                          *((struct config_real *) record)->variable);
5188                         return buffer;
5189
5190                 case PGC_STRING:
5191                         return *((struct config_string *) record)->variable;
5192
5193                 case PGC_ENUM:
5194                         return config_enum_lookup_by_value((struct config_enum *) record,
5195                                                                  *((struct config_enum *) record)->variable);
5196         }
5197         return NULL;
5198 }
5199
5200 /*
5201  * Get the RESET value associated with the given option.
5202  *
5203  * Note: this is not re-entrant, due to use of static result buffer;
5204  * not to mention that a string variable could have its reset_val changed.
5205  * Beware of assuming the result value is good for very long.
5206  */
5207 const char *
5208 GetConfigOptionResetString(const char *name)
5209 {
5210         struct config_generic *record;
5211         static char buffer[256];
5212
5213         record = find_option(name, false, ERROR);
5214         if (record == NULL)
5215                 ereport(ERROR,
5216                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5217                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5218         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
5219                 ereport(ERROR,
5220                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5221                                  errmsg("must be superuser to examine \"%s\"", name)));
5222
5223         switch (record->vartype)
5224         {
5225                 case PGC_BOOL:
5226                         return ((struct config_bool *) record)->reset_val ? "on" : "off";
5227
5228                 case PGC_INT:
5229                         snprintf(buffer, sizeof(buffer), "%d",
5230                                          ((struct config_int *) record)->reset_val);
5231                         return buffer;
5232
5233                 case PGC_REAL:
5234                         snprintf(buffer, sizeof(buffer), "%g",
5235                                          ((struct config_real *) record)->reset_val);
5236                         return buffer;
5237
5238                 case PGC_STRING:
5239                         return ((struct config_string *) record)->reset_val;
5240
5241                 case PGC_ENUM:
5242                         return config_enum_lookup_by_value((struct config_enum *) record,
5243                                                                  ((struct config_enum *) record)->reset_val);
5244         }
5245         return NULL;
5246 }
5247
5248
5249 /*
5250  * GUC_complaint_elevel
5251  *              Get the ereport error level to use in an assign_hook's error report.
5252  *
5253  * This should be used by assign hooks that want to emit a custom error
5254  * report (in addition to the generic "invalid value for option FOO" that
5255  * guc.c will provide).  Note that the result might be ERROR or a lower
5256  * level, so the caller must be prepared for control to return from ereport,
5257  * or not.      If control does return, return false/NULL from the hook function.
5258  *
5259  * At some point it'd be nice to replace this with a mechanism that allows
5260  * the custom message to become the DETAIL line of guc.c's generic message.
5261  */
5262 int
5263 GUC_complaint_elevel(GucSource source)
5264 {
5265         int                     elevel;
5266
5267         if (source == PGC_S_FILE)
5268         {
5269                 /*
5270                  * To avoid cluttering the log, only the postmaster bleats loudly
5271                  * about problems with the config file.
5272                  */
5273                 elevel = IsUnderPostmaster ? DEBUG3 : LOG;
5274         }
5275         else if (source == PGC_S_OVERRIDE)
5276         {
5277                 /*
5278                  * If we're a postmaster child, this is probably "undo" during
5279                  * transaction abort, so we don't want to clutter the log.  There's a
5280                  * small chance of a real problem with an OVERRIDE setting, though, so
5281                  * suppressing the message entirely wouldn't be desirable.
5282                  */
5283                 elevel = IsUnderPostmaster ? DEBUG5 : LOG;
5284         }
5285         else if (source < PGC_S_INTERACTIVE)
5286                 elevel = LOG;
5287         else
5288                 elevel = ERROR;
5289
5290         return elevel;
5291 }
5292
5293
5294 /*
5295  * flatten_set_variable_args
5296  *              Given a parsenode List as emitted by the grammar for SET,
5297  *              convert to the flat string representation used by GUC.
5298  *
5299  * We need to be told the name of the variable the args are for, because
5300  * the flattening rules vary (ugh).
5301  *
5302  * The result is NULL if args is NIL (ie, SET ... TO DEFAULT), otherwise
5303  * a palloc'd string.
5304  */
5305 static char *
5306 flatten_set_variable_args(const char *name, List *args)
5307 {
5308         struct config_generic *record;
5309         int                     flags;
5310         StringInfoData buf;
5311         ListCell   *l;
5312
5313         /* Fast path if just DEFAULT */
5314         if (args == NIL)
5315                 return NULL;
5316
5317         /* Else get flags for the variable */
5318         record = find_option(name, true, ERROR);
5319         if (record == NULL)
5320                 ereport(ERROR,
5321                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5322                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5323
5324         flags = record->flags;
5325
5326         /* Complain if list input and non-list variable */
5327         if ((flags & GUC_LIST_INPUT) == 0 &&
5328                 list_length(args) != 1)
5329                 ereport(ERROR,
5330                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5331                                  errmsg("SET %s takes only one argument", name)));
5332
5333         initStringInfo(&buf);
5334
5335         /*
5336          * Each list member may be a plain A_Const node, or an A_Const within a
5337          * TypeCast; the latter case is supported only for ConstInterval arguments
5338          * (for SET TIME ZONE).
5339          */
5340         foreach(l, args)
5341         {
5342                 Node       *arg = (Node *) lfirst(l);
5343                 char       *val;
5344                 TypeName   *typeName = NULL;
5345                 A_Const    *con;
5346
5347                 if (l != list_head(args))
5348                         appendStringInfo(&buf, ", ");
5349
5350                 if (IsA(arg, TypeCast))
5351                 {
5352                         TypeCast   *tc = (TypeCast *) arg;
5353
5354                         arg = tc->arg;
5355                         typeName = tc->typeName;
5356                 }
5357
5358                 if (!IsA(arg, A_Const))
5359                         elog(ERROR, "unrecognized node type: %d", (int) nodeTag(arg));
5360                 con = (A_Const *) arg;
5361
5362                 switch (nodeTag(&con->val))
5363                 {
5364                         case T_Integer:
5365                                 appendStringInfo(&buf, "%ld", intVal(&con->val));
5366                                 break;
5367                         case T_Float:
5368                                 /* represented as a string, so just copy it */
5369                                 appendStringInfoString(&buf, strVal(&con->val));
5370                                 break;
5371                         case T_String:
5372                                 val = strVal(&con->val);
5373                                 if (typeName != NULL)
5374                                 {
5375                                         /*
5376                                          * Must be a ConstInterval argument for TIME ZONE. Coerce
5377                                          * to interval and back to normalize the value and account
5378                                          * for any typmod.
5379                                          */
5380                                         Oid                     typoid;
5381                                         int32           typmod;
5382                                         Datum           interval;
5383                                         char       *intervalout;
5384
5385                                         typoid = typenameTypeId(NULL, typeName, &typmod);
5386                                         Assert(typoid == INTERVALOID);
5387
5388                                         interval =
5389                                                 DirectFunctionCall3(interval_in,
5390                                                                                         CStringGetDatum(val),
5391                                                                                         ObjectIdGetDatum(InvalidOid),
5392                                                                                         Int32GetDatum(typmod));
5393
5394                                         intervalout =
5395                                                 DatumGetCString(DirectFunctionCall1(interval_out,
5396                                                                                                                         interval));
5397                                         appendStringInfo(&buf, "INTERVAL '%s'", intervalout);
5398                                 }
5399                                 else
5400                                 {
5401                                         /*
5402                                          * Plain string literal or identifier.  For quote mode,
5403                                          * quote it if it's not a vanilla identifier.
5404                                          */
5405                                         if (flags & GUC_LIST_QUOTE)
5406                                                 appendStringInfoString(&buf, quote_identifier(val));
5407                                         else
5408                                                 appendStringInfoString(&buf, val);
5409                                 }
5410                                 break;
5411                         default:
5412                                 elog(ERROR, "unrecognized node type: %d",
5413                                          (int) nodeTag(&con->val));
5414                                 break;
5415                 }
5416         }
5417
5418         return buf.data;
5419 }
5420
5421
5422 /*
5423  * SET command
5424  */
5425 void
5426 ExecSetVariableStmt(VariableSetStmt *stmt)
5427 {
5428         GucAction       action = stmt->is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET;
5429
5430         switch (stmt->kind)
5431         {
5432                 case VAR_SET_VALUE:
5433                 case VAR_SET_CURRENT:
5434                         set_config_option(stmt->name,
5435                                                           ExtractSetVariableArgs(stmt),
5436                                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5437                                                           PGC_S_SESSION,
5438                                                           action,
5439                                                           true);
5440                         break;
5441                 case VAR_SET_MULTI:
5442
5443                         /*
5444                          * Special case for special SQL syntax that effectively sets more
5445                          * than one variable per statement.
5446                          */
5447                         if (strcmp(stmt->name, "TRANSACTION") == 0)
5448                         {
5449                                 ListCell   *head;
5450
5451                                 foreach(head, stmt->args)
5452                                 {
5453                                         DefElem    *item = (DefElem *) lfirst(head);
5454
5455                                         if (strcmp(item->defname, "transaction_isolation") == 0)
5456                                                 SetPGVariable("transaction_isolation",
5457                                                                           list_make1(item->arg), stmt->is_local);
5458                                         else if (strcmp(item->defname, "transaction_read_only") == 0)
5459                                                 SetPGVariable("transaction_read_only",
5460                                                                           list_make1(item->arg), stmt->is_local);
5461                                         else
5462                                                 elog(ERROR, "unexpected SET TRANSACTION element: %s",
5463                                                          item->defname);
5464                                 }
5465                         }
5466                         else if (strcmp(stmt->name, "SESSION CHARACTERISTICS") == 0)
5467                         {
5468                                 ListCell   *head;
5469
5470                                 foreach(head, stmt->args)
5471                                 {
5472                                         DefElem    *item = (DefElem *) lfirst(head);
5473
5474                                         if (strcmp(item->defname, "transaction_isolation") == 0)
5475                                                 SetPGVariable("default_transaction_isolation",
5476                                                                           list_make1(item->arg), stmt->is_local);
5477                                         else if (strcmp(item->defname, "transaction_read_only") == 0)
5478                                                 SetPGVariable("default_transaction_read_only",
5479                                                                           list_make1(item->arg), stmt->is_local);
5480                                         else
5481                                                 elog(ERROR, "unexpected SET SESSION element: %s",
5482                                                          item->defname);
5483                                 }
5484                         }
5485                         else
5486                                 elog(ERROR, "unexpected SET MULTI element: %s",
5487                                          stmt->name);
5488                         break;
5489                 case VAR_SET_DEFAULT:
5490                 case VAR_RESET:
5491                         set_config_option(stmt->name,
5492                                                           NULL,
5493                                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5494                                                           PGC_S_SESSION,
5495                                                           action,
5496                                                           true);
5497                         break;
5498                 case VAR_RESET_ALL:
5499                         ResetAllOptions();
5500                         break;
5501         }
5502 }
5503
5504 /*
5505  * Get the value to assign for a VariableSetStmt, or NULL if it's RESET.
5506  * The result is palloc'd.
5507  *
5508  * This is exported for use by actions such as ALTER ROLE SET.
5509  */
5510 char *
5511 ExtractSetVariableArgs(VariableSetStmt *stmt)
5512 {
5513         switch (stmt->kind)
5514         {
5515                 case VAR_SET_VALUE:
5516                         return flatten_set_variable_args(stmt->name, stmt->args);
5517                 case VAR_SET_CURRENT:
5518                         return GetConfigOptionByName(stmt->name, NULL);
5519                 default:
5520                         return NULL;
5521         }
5522 }
5523
5524 /*
5525  * SetPGVariable - SET command exported as an easily-C-callable function.
5526  *
5527  * This provides access to SET TO value, as well as SET TO DEFAULT (expressed
5528  * by passing args == NIL), but not SET FROM CURRENT functionality.
5529  */
5530 void
5531 SetPGVariable(const char *name, List *args, bool is_local)
5532 {
5533         char       *argstring = flatten_set_variable_args(name, args);
5534
5535         /* Note SET DEFAULT (argstring == NULL) is equivalent to RESET */
5536         set_config_option(name,
5537                                           argstring,
5538                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5539                                           PGC_S_SESSION,
5540                                           is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET,
5541                                           true);
5542 }
5543
5544 /*
5545  * SET command wrapped as a SQL callable function.
5546  */
5547 Datum
5548 set_config_by_name(PG_FUNCTION_ARGS)
5549 {
5550         char       *name;
5551         char       *value;
5552         char       *new_value;
5553         bool            is_local;
5554
5555         if (PG_ARGISNULL(0))
5556                 ereport(ERROR,
5557                                 (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
5558                                  errmsg("SET requires parameter name")));
5559
5560         /* Get the GUC variable name */
5561         name = TextDatumGetCString(PG_GETARG_DATUM(0));
5562
5563         /* Get the desired value or set to NULL for a reset request */
5564         if (PG_ARGISNULL(1))
5565                 value = NULL;
5566         else
5567                 value = TextDatumGetCString(PG_GETARG_DATUM(1));
5568
5569         /*
5570          * Get the desired state of is_local. Default to false if provided value
5571          * is NULL
5572          */
5573         if (PG_ARGISNULL(2))
5574                 is_local = false;
5575         else
5576                 is_local = PG_GETARG_BOOL(2);
5577
5578         /* Note SET DEFAULT (argstring == NULL) is equivalent to RESET */
5579         set_config_option(name,
5580                                           value,
5581                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5582                                           PGC_S_SESSION,
5583                                           is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET,
5584                                           true);
5585
5586         /* get the new current value */
5587         new_value = GetConfigOptionByName(name, NULL);
5588
5589         /* Convert return string to text */
5590         PG_RETURN_TEXT_P(cstring_to_text(new_value));
5591 }
5592
5593
5594 /*
5595  * Common code for DefineCustomXXXVariable subroutines: allocate the
5596  * new variable's config struct and fill in generic fields.
5597  */
5598 static struct config_generic *
5599 init_custom_variable(const char *name,
5600                                          const char *short_desc,
5601                                          const char *long_desc,
5602                                          GucContext context,
5603                                          int flags,
5604                                          enum config_type type,
5605                                          size_t sz)
5606 {
5607         struct config_generic *gen;
5608
5609         /*
5610          * Only allow custom PGC_POSTMASTER variables to be created during shared
5611          * library preload; any later than that, we can't ensure that the value
5612          * doesn't change after startup.  This is a fatal elog if it happens; just
5613          * erroring out isn't safe because we don't know what the calling loadable
5614          * module might already have hooked into.
5615          */
5616         if (context == PGC_POSTMASTER &&
5617                 !process_shared_preload_libraries_in_progress)
5618                 elog(FATAL, "cannot create PGC_POSTMASTER variables after startup");
5619
5620         gen = (struct config_generic *) guc_malloc(ERROR, sz);
5621         memset(gen, 0, sz);
5622
5623         gen->name = guc_strdup(ERROR, name);
5624         gen->context = context;
5625         gen->group = CUSTOM_OPTIONS;
5626         gen->short_desc = short_desc;
5627         gen->long_desc = long_desc;
5628         gen->flags = flags;
5629         gen->vartype = type;
5630
5631         return gen;
5632 }
5633
5634 /*
5635  * Common code for DefineCustomXXXVariable subroutines: insert the new
5636  * variable into the GUC variable array, replacing any placeholder.
5637  */
5638 static void
5639 define_custom_variable(struct config_generic * variable)
5640 {
5641         const char *name = variable->name;
5642         const char **nameAddr = &name;
5643         const char *value;
5644         struct config_string *pHolder;
5645         GucContext      phcontext;
5646         struct config_generic **res;
5647
5648         /*
5649          * See if there's a placeholder by the same name.
5650          */
5651         res = (struct config_generic **) bsearch((void *) &nameAddr,
5652                                                                                          (void *) guc_variables,
5653                                                                                          num_guc_variables,
5654                                                                                          sizeof(struct config_generic *),
5655                                                                                          guc_var_compare);
5656         if (res == NULL)
5657         {
5658                 /*
5659                  * No placeholder to replace, so we can just add it ... but first,
5660                  * make sure it's initialized to its default value.
5661                  */
5662                 InitializeOneGUCOption(variable);
5663                 add_guc_variable(variable, ERROR);
5664                 return;
5665         }
5666
5667         /*
5668          * This better be a placeholder
5669          */
5670         if (((*res)->flags & GUC_CUSTOM_PLACEHOLDER) == 0)
5671                 ereport(ERROR,
5672                                 (errcode(ERRCODE_INTERNAL_ERROR),
5673                                  errmsg("attempt to redefine parameter \"%s\"", name)));
5674
5675         Assert((*res)->vartype == PGC_STRING);
5676         pHolder = (struct config_string *) (*res);
5677
5678         /*
5679          * First, set the variable to its default value.  We must do this even
5680          * though we intend to immediately apply a new value, since it's possible
5681          * that the new value is invalid.
5682          */
5683         InitializeOneGUCOption(variable);
5684
5685         /*
5686          * Replace the placeholder. We aren't changing the name, so no re-sorting
5687          * is necessary
5688          */
5689         *res = variable;
5690
5691         /*
5692          * Infer context for assignment based on source of existing value. We
5693          * can't tell this with exact accuracy, but we can at least do something
5694          * reasonable in typical cases.
5695          */
5696         switch (pHolder->gen.source)
5697         {
5698                 case PGC_S_DEFAULT:
5699                 case PGC_S_ENV_VAR:
5700                 case PGC_S_FILE:
5701                 case PGC_S_ARGV:
5702
5703                         /*
5704                          * If we got past the check in init_custom_variable, we can safely
5705                          * assume that any existing value for a PGC_POSTMASTER variable
5706                          * was set in postmaster context.
5707                          */
5708                         if (variable->context == PGC_POSTMASTER)
5709                                 phcontext = PGC_POSTMASTER;
5710                         else
5711                                 phcontext = PGC_SIGHUP;
5712                         break;
5713                 case PGC_S_DATABASE:
5714                 case PGC_S_USER:
5715                 case PGC_S_CLIENT:
5716                 case PGC_S_SESSION:
5717                 default:
5718                         phcontext = PGC_USERSET;
5719                         break;
5720         }
5721
5722         /*
5723          * Assign the string value stored in the placeholder to the real variable.
5724          *
5725          * XXX this is not really good enough --- it should be a nontransactional
5726          * assignment, since we don't want it to roll back if the current xact
5727          * fails later.  (Or do we?)
5728          */
5729         value = *pHolder->variable;
5730
5731         if (value)
5732         {
5733                 if (set_config_option(name, value,
5734                                                           phcontext, pHolder->gen.source,
5735                                                           GUC_ACTION_SET, true))
5736                 {
5737                         /* Also copy over any saved source-location information */
5738                         if (pHolder->gen.sourcefile)
5739                                 set_config_sourcefile(name, pHolder->gen.sourcefile,
5740                                                                           pHolder->gen.sourceline);
5741                 }
5742         }
5743
5744         /*
5745          * Free up as much as we conveniently can of the placeholder structure
5746          * (this neglects any stack items...)
5747          */
5748         set_string_field(pHolder, pHolder->variable, NULL);
5749         set_string_field(pHolder, &pHolder->reset_val, NULL);
5750
5751         free(pHolder);
5752 }
5753
5754 void
5755 DefineCustomBoolVariable(const char *name,
5756                                                  const char *short_desc,
5757                                                  const char *long_desc,
5758                                                  bool *valueAddr,
5759                                                  bool bootValue,
5760                                                  GucContext context,
5761                                                  int flags,
5762                                                  GucBoolAssignHook assign_hook,
5763                                                  GucShowHook show_hook)
5764 {
5765         struct config_bool *var;
5766
5767         var = (struct config_bool *)
5768                 init_custom_variable(name, short_desc, long_desc, context, flags,
5769                                                          PGC_BOOL, sizeof(struct config_bool));
5770         var->variable = valueAddr;
5771         var->boot_val = bootValue;
5772         var->reset_val = bootValue;
5773         var->assign_hook = assign_hook;
5774         var->show_hook = show_hook;
5775         define_custom_variable(&var->gen);
5776 }
5777
5778 void
5779 DefineCustomIntVariable(const char *name,
5780                                                 const char *short_desc,
5781                                                 const char *long_desc,
5782                                                 int *valueAddr,
5783                                                 int bootValue,
5784                                                 int minValue,
5785                                                 int maxValue,
5786                                                 GucContext context,
5787                                                 int flags,
5788                                                 GucIntAssignHook assign_hook,
5789                                                 GucShowHook show_hook)
5790 {
5791         struct config_int *var;
5792
5793         var = (struct config_int *)
5794                 init_custom_variable(name, short_desc, long_desc, context, flags,
5795                                                          PGC_INT, sizeof(struct config_int));
5796         var->variable = valueAddr;
5797         var->boot_val = bootValue;
5798         var->reset_val = bootValue;
5799         var->min = minValue;
5800         var->max = maxValue;
5801         var->assign_hook = assign_hook;
5802         var->show_hook = show_hook;
5803         define_custom_variable(&var->gen);
5804 }
5805
5806 void
5807 DefineCustomRealVariable(const char *name,
5808                                                  const char *short_desc,
5809                                                  const char *long_desc,
5810                                                  double *valueAddr,
5811                                                  double bootValue,
5812                                                  double minValue,
5813                                                  double maxValue,
5814                                                  GucContext context,
5815                                                  int flags,
5816                                                  GucRealAssignHook assign_hook,
5817                                                  GucShowHook show_hook)
5818 {
5819         struct config_real *var;
5820
5821         var = (struct config_real *)
5822                 init_custom_variable(name, short_desc, long_desc, context, flags,
5823                                                          PGC_REAL, sizeof(struct config_real));
5824         var->variable = valueAddr;
5825         var->boot_val = bootValue;
5826         var->reset_val = bootValue;
5827         var->min = minValue;
5828         var->max = maxValue;
5829         var->assign_hook = assign_hook;
5830         var->show_hook = show_hook;
5831         define_custom_variable(&var->gen);
5832 }
5833
5834 void
5835 DefineCustomStringVariable(const char *name,
5836                                                    const char *short_desc,
5837                                                    const char *long_desc,
5838                                                    char **valueAddr,
5839                                                    const char *bootValue,
5840                                                    GucContext context,
5841                                                    int flags,
5842                                                    GucStringAssignHook assign_hook,
5843                                                    GucShowHook show_hook)
5844 {
5845         struct config_string *var;
5846
5847         var = (struct config_string *)
5848                 init_custom_variable(name, short_desc, long_desc, context, flags,
5849                                                          PGC_STRING, sizeof(struct config_string));
5850         var->variable = valueAddr;
5851         var->boot_val = bootValue;
5852         /* we could probably do without strdup, but keep it like normal case */
5853         if (var->boot_val)
5854                 var->reset_val = guc_strdup(ERROR, var->boot_val);
5855         var->assign_hook = assign_hook;
5856         var->show_hook = show_hook;
5857         define_custom_variable(&var->gen);
5858 }
5859
5860 void
5861 DefineCustomEnumVariable(const char *name,
5862                                                  const char *short_desc,
5863                                                  const char *long_desc,
5864                                                  int *valueAddr,
5865                                                  int bootValue,
5866                                                  const struct config_enum_entry * options,
5867                                                  GucContext context,
5868                                                  int flags,
5869                                                  GucEnumAssignHook assign_hook,
5870                                                  GucShowHook show_hook)
5871 {
5872         struct config_enum *var;
5873
5874         var = (struct config_enum *)
5875                 init_custom_variable(name, short_desc, long_desc, context, flags,
5876                                                          PGC_ENUM, sizeof(struct config_enum));
5877         var->variable = valueAddr;
5878         var->boot_val = bootValue;
5879         var->reset_val = bootValue;
5880         var->options = options;
5881         var->assign_hook = assign_hook;
5882         var->show_hook = show_hook;
5883         define_custom_variable(&var->gen);
5884 }
5885
5886 void
5887 EmitWarningsOnPlaceholders(const char *className)
5888 {
5889         int                     classLen = strlen(className);
5890         int                     i;
5891
5892         for (i = 0; i < num_guc_variables; i++)
5893         {
5894                 struct config_generic *var = guc_variables[i];
5895
5896                 if ((var->flags & GUC_CUSTOM_PLACEHOLDER) != 0 &&
5897                         strncmp(className, var->name, classLen) == 0 &&
5898                         var->name[classLen] == GUC_QUALIFIER_SEPARATOR)
5899                 {
5900                         ereport(WARNING,
5901                                         (errcode(ERRCODE_UNDEFINED_OBJECT),
5902                                          errmsg("unrecognized configuration parameter \"%s\"",
5903                                                         var->name)));
5904                 }
5905         }
5906 }
5907
5908
5909 /*
5910  * SHOW command
5911  */
5912 void
5913 GetPGVariable(const char *name, DestReceiver *dest)
5914 {
5915         if (guc_name_compare(name, "all") == 0)
5916                 ShowAllGUCConfig(dest);
5917         else
5918                 ShowGUCConfigOption(name, dest);
5919 }
5920
5921 TupleDesc
5922 GetPGVariableResultDesc(const char *name)
5923 {
5924         TupleDesc       tupdesc;
5925
5926         if (guc_name_compare(name, "all") == 0)
5927         {
5928                 /* need a tuple descriptor representing three TEXT columns */
5929                 tupdesc = CreateTemplateTupleDesc(3, false);
5930                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
5931                                                    TEXTOID, -1, 0);
5932                 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
5933                                                    TEXTOID, -1, 0);
5934                 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "description",
5935                                                    TEXTOID, -1, 0);
5936         }
5937         else
5938         {
5939                 const char *varname;
5940
5941                 /* Get the canonical spelling of name */
5942                 (void) GetConfigOptionByName(name, &varname);
5943
5944                 /* need a tuple descriptor representing a single TEXT column */
5945                 tupdesc = CreateTemplateTupleDesc(1, false);
5946                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, varname,
5947                                                    TEXTOID, -1, 0);
5948         }
5949         return tupdesc;
5950 }
5951
5952
5953 /*
5954  * SHOW command
5955  */
5956 static void
5957 ShowGUCConfigOption(const char *name, DestReceiver *dest)
5958 {
5959         TupOutputState *tstate;
5960         TupleDesc       tupdesc;
5961         const char *varname;
5962         char       *value;
5963
5964         /* Get the value and canonical spelling of name */
5965         value = GetConfigOptionByName(name, &varname);
5966
5967         /* need a tuple descriptor representing a single TEXT column */
5968         tupdesc = CreateTemplateTupleDesc(1, false);
5969         TupleDescInitEntry(tupdesc, (AttrNumber) 1, varname,
5970                                            TEXTOID, -1, 0);
5971
5972         /* prepare for projection of tuples */
5973         tstate = begin_tup_output_tupdesc(dest, tupdesc);
5974
5975         /* Send it */
5976         do_text_output_oneline(tstate, value);
5977
5978         end_tup_output(tstate);
5979 }
5980
5981 /*
5982  * SHOW ALL command
5983  */
5984 static void
5985 ShowAllGUCConfig(DestReceiver *dest)
5986 {
5987         bool            am_superuser = superuser();
5988         int                     i;
5989         TupOutputState *tstate;
5990         TupleDesc       tupdesc;
5991         Datum       values[3];
5992         bool            isnull[3] = { false, false, false };
5993
5994         /* need a tuple descriptor representing three TEXT columns */
5995         tupdesc = CreateTemplateTupleDesc(3, false);
5996         TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
5997                                            TEXTOID, -1, 0);
5998         TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
5999                                            TEXTOID, -1, 0);
6000         TupleDescInitEntry(tupdesc, (AttrNumber) 3, "description",
6001                                            TEXTOID, -1, 0);
6002
6003         /* prepare for projection of tuples */
6004         tstate = begin_tup_output_tupdesc(dest, tupdesc);
6005
6006         for (i = 0; i < num_guc_variables; i++)
6007         {
6008                 struct config_generic *conf = guc_variables[i];
6009                 char   *setting;
6010
6011                 if ((conf->flags & GUC_NO_SHOW_ALL) ||
6012                         ((conf->flags & GUC_SUPERUSER_ONLY) && !am_superuser))
6013                         continue;
6014
6015                 /* assign to the values array */
6016                 values[0] = PointerGetDatum(cstring_to_text(conf->name));
6017
6018                 setting = _ShowOption(conf, true);
6019                 if (setting)
6020                 {
6021                         values[1] = PointerGetDatum(cstring_to_text(setting));
6022                         isnull[1] = false;
6023                 }
6024                 else
6025                 {
6026                         values[1] = PointerGetDatum(NULL);
6027                         isnull[1] = true;
6028                 }
6029
6030                 values[2] = PointerGetDatum(cstring_to_text(conf->short_desc));
6031
6032                 /* send it to dest */
6033                 do_tup_output(tstate, values, isnull);
6034
6035                 /* clean up */
6036                 pfree(DatumGetPointer(values[0]));
6037                 if (setting)
6038                 {
6039                         pfree(setting);
6040                         pfree(DatumGetPointer(values[1]));
6041                 }
6042                 pfree(DatumGetPointer(values[2]));
6043         }
6044
6045         end_tup_output(tstate);
6046 }
6047
6048 /*
6049  * Return GUC variable value by name; optionally return canonical
6050  * form of name.  Return value is palloc'd.
6051  */
6052 char *
6053 GetConfigOptionByName(const char *name, const char **varname)
6054 {
6055         struct config_generic *record;
6056
6057         record = find_option(name, false, ERROR);
6058         if (record == NULL)
6059                 ereport(ERROR,
6060                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
6061                            errmsg("unrecognized configuration parameter \"%s\"", name)));
6062         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
6063                 ereport(ERROR,
6064                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
6065                                  errmsg("must be superuser to examine \"%s\"", name)));
6066
6067         if (varname)
6068                 *varname = record->name;
6069
6070         return _ShowOption(record, true);
6071 }
6072
6073 /*
6074  * Return GUC variable value by variable number; optionally return canonical
6075  * form of name.  Return value is palloc'd.
6076  */
6077 void
6078 GetConfigOptionByNum(int varnum, const char **values, bool *noshow)
6079 {
6080         char            buffer[256];
6081         struct config_generic *conf;
6082
6083         /* check requested variable number valid */
6084         Assert((varnum >= 0) && (varnum < num_guc_variables));
6085
6086         conf = guc_variables[varnum];
6087
6088         if (noshow)
6089         {
6090                 if ((conf->flags & GUC_NO_SHOW_ALL) ||
6091                         ((conf->flags & GUC_SUPERUSER_ONLY) && !superuser()))
6092                         *noshow = true;
6093                 else
6094                         *noshow = false;
6095         }
6096
6097         /* first get the generic attributes */
6098
6099         /* name */
6100         values[0] = conf->name;
6101
6102         /* setting : use _ShowOption in order to avoid duplicating the logic */
6103         values[1] = _ShowOption(conf, false);
6104
6105         /* unit */
6106         if (conf->vartype == PGC_INT)
6107         {
6108                 static char buf[8];
6109
6110                 switch (conf->flags & (GUC_UNIT_MEMORY | GUC_UNIT_TIME))
6111                 {
6112                         case GUC_UNIT_KB:
6113                                 values[2] = "kB";
6114                                 break;
6115                         case GUC_UNIT_BLOCKS:
6116                                 snprintf(buf, sizeof(buf), "%dkB", BLCKSZ / 1024);
6117                                 values[2] = buf;
6118                                 break;
6119                         case GUC_UNIT_XBLOCKS:
6120                                 snprintf(buf, sizeof(buf), "%dkB", XLOG_BLCKSZ / 1024);
6121                                 values[2] = buf;
6122                                 break;
6123                         case GUC_UNIT_MS:
6124                                 values[2] = "ms";
6125                                 break;
6126                         case GUC_UNIT_S:
6127                                 values[2] = "s";
6128                                 break;
6129                         case GUC_UNIT_MIN:
6130                                 values[2] = "min";
6131                                 break;
6132                         default:
6133                                 values[2] = "";
6134                                 break;
6135                 }
6136         }
6137         else
6138                 values[2] = NULL;
6139
6140         /* group */
6141         values[3] = config_group_names[conf->group];
6142
6143         /* short_desc */
6144         values[4] = conf->short_desc;
6145
6146         /* extra_desc */
6147         values[5] = conf->long_desc;
6148
6149         /* context */
6150         values[6] = GucContext_Names[conf->context];
6151
6152         /* vartype */
6153         values[7] = config_type_names[conf->vartype];
6154
6155         /* source */
6156         values[8] = GucSource_Names[conf->source];
6157
6158         /* now get the type specifc attributes */
6159         switch (conf->vartype)
6160         {
6161                 case PGC_BOOL:
6162                         {
6163                                 struct config_bool *lconf = (struct config_bool *) conf;
6164
6165                                 /* min_val */
6166                                 values[9] = NULL;
6167
6168                                 /* max_val */
6169                                 values[10] = NULL;
6170
6171                                 /* enumvals */
6172                                 values[11] = NULL;
6173
6174                                 /* boot_val */
6175                                 values[12] = pstrdup(lconf->boot_val ? "on" : "off");
6176
6177                                 /* reset_val */
6178                                 values[13] = pstrdup(lconf->reset_val ? "on" : "off");
6179                         }
6180                         break;
6181
6182                 case PGC_INT:
6183                         {
6184                                 struct config_int *lconf = (struct config_int *) conf;
6185
6186                                 /* min_val */
6187                                 snprintf(buffer, sizeof(buffer), "%d", lconf->min);
6188                                 values[9] = pstrdup(buffer);
6189
6190                                 /* max_val */
6191                                 snprintf(buffer, sizeof(buffer), "%d", lconf->max);
6192                                 values[10] = pstrdup(buffer);
6193
6194                                 /* enumvals */
6195                                 values[11] = NULL;
6196
6197                                 /* boot_val */
6198                                 snprintf(buffer, sizeof(buffer), "%d", lconf->boot_val);
6199                                 values[12] = pstrdup(buffer);
6200
6201                                 /* reset_val */
6202                                 snprintf(buffer, sizeof(buffer), "%d", lconf->reset_val);
6203                                 values[13] = pstrdup(buffer);
6204                         }
6205                         break;
6206
6207                 case PGC_REAL:
6208                         {
6209                                 struct config_real *lconf = (struct config_real *) conf;
6210
6211                                 /* min_val */
6212                                 snprintf(buffer, sizeof(buffer), "%g", lconf->min);
6213                                 values[9] = pstrdup(buffer);
6214
6215                                 /* max_val */
6216                                 snprintf(buffer, sizeof(buffer), "%g", lconf->max);
6217                                 values[10] = pstrdup(buffer);
6218
6219                                 /* enumvals */
6220                                 values[11] = NULL;
6221
6222                                 /* boot_val */
6223                                 snprintf(buffer, sizeof(buffer), "%g", lconf->boot_val);
6224                                 values[12] = pstrdup(buffer);
6225
6226                                 /* reset_val */
6227                                 snprintf(buffer, sizeof(buffer), "%g", lconf->reset_val);
6228                                 values[13] = pstrdup(buffer);
6229                         }
6230                         break;
6231
6232                 case PGC_STRING:
6233                         {
6234                                 struct config_string *lconf = (struct config_string *) conf;
6235
6236                                 /* min_val */
6237                                 values[9] = NULL;
6238
6239                                 /* max_val */
6240                                 values[10] = NULL;
6241
6242                                 /* enumvals */
6243                                 values[11] = NULL;
6244
6245                                 /* boot_val */
6246                                 if (lconf->boot_val == NULL)
6247                                         values[12] = NULL;
6248                                 else
6249                                         values[12] = pstrdup(lconf->boot_val);
6250
6251                                 /* reset_val */
6252                                 if (lconf->reset_val == NULL)
6253                                         values[13] = NULL;
6254                                 else
6255                                         values[13] = pstrdup(lconf->reset_val);
6256                         }
6257                         break;
6258
6259                 case PGC_ENUM:
6260                         {
6261                                 struct config_enum *lconf = (struct config_enum *) conf;
6262
6263                                 /* min_val */
6264                                 values[9] = NULL;
6265
6266                                 /* max_val */
6267                                 values[10] = NULL;
6268
6269                                 /* enumvals */
6270
6271                                 /*
6272                                  * NOTE! enumvals with double quotes in them are not
6273                                  * supported!
6274                                  */
6275                                 values[11] = config_enum_get_options((struct config_enum *) conf,
6276                                                                                                          "{\"", "\"}", "\",\"");
6277
6278                                 /* boot_val */
6279                                 values[12] = pstrdup(config_enum_lookup_by_value(lconf,
6280                                                                                                                    lconf->boot_val));
6281
6282                                 /* reset_val */
6283                                 values[13] = pstrdup(config_enum_lookup_by_value(lconf,
6284                                                                                                                   lconf->reset_val));
6285                         }
6286                         break;
6287
6288                 default:
6289                         {
6290                                 /*
6291                                  * should never get here, but in case we do, set 'em to NULL
6292                                  */
6293
6294                                 /* min_val */
6295                                 values[9] = NULL;
6296
6297                                 /* max_val */
6298                                 values[10] = NULL;
6299
6300                                 /* enumvals */
6301                                 values[11] = NULL;
6302
6303                                 /* boot_val */
6304                                 values[12] = NULL;
6305
6306                                 /* reset_val */
6307                                 values[13] = NULL;
6308                         }
6309                         break;
6310         }
6311
6312         /*
6313          * If the setting came from a config file, set the source location. For
6314          * security reasons, we don't show source file/line number for
6315          * non-superusers.
6316          */
6317         if (conf->source == PGC_S_FILE && superuser())
6318         {
6319                 values[14] = conf->sourcefile;
6320                 snprintf(buffer, sizeof(buffer), "%d", conf->sourceline);
6321                 values[15] = pstrdup(buffer);
6322         }
6323         else
6324         {
6325                 values[14] = NULL;
6326                 values[15] = NULL;
6327         }
6328 }
6329
6330 /*
6331  * Return the total number of GUC variables
6332  */
6333 int
6334 GetNumConfigOptions(void)
6335 {
6336         return num_guc_variables;
6337 }
6338
6339 /*
6340  * show_config_by_name - equiv to SHOW X command but implemented as
6341  * a function.
6342  */
6343 Datum
6344 show_config_by_name(PG_FUNCTION_ARGS)
6345 {
6346         char       *varname;
6347         char       *varval;
6348
6349         /* Get the GUC variable name */
6350         varname = TextDatumGetCString(PG_GETARG_DATUM(0));
6351
6352         /* Get the value */
6353         varval = GetConfigOptionByName(varname, NULL);
6354
6355         /* Convert to text */
6356         PG_RETURN_TEXT_P(cstring_to_text(varval));
6357 }
6358
6359 /*
6360  * show_all_settings - equiv to SHOW ALL command but implemented as
6361  * a Table Function.
6362  */
6363 #define NUM_PG_SETTINGS_ATTS    16
6364
6365 Datum
6366 show_all_settings(PG_FUNCTION_ARGS)
6367 {
6368         FuncCallContext *funcctx;
6369         TupleDesc       tupdesc;
6370         int                     call_cntr;
6371         int                     max_calls;
6372         AttInMetadata *attinmeta;
6373         MemoryContext oldcontext;
6374
6375         /* stuff done only on the first call of the function */
6376         if (SRF_IS_FIRSTCALL())
6377         {
6378                 /* create a function context for cross-call persistence */
6379                 funcctx = SRF_FIRSTCALL_INIT();
6380
6381                 /*
6382                  * switch to memory context appropriate for multiple function calls
6383                  */
6384                 oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
6385
6386                 /*
6387                  * need a tuple descriptor representing NUM_PG_SETTINGS_ATTS columns
6388                  * of the appropriate types
6389                  */
6390                 tupdesc = CreateTemplateTupleDesc(NUM_PG_SETTINGS_ATTS, false);
6391                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
6392                                                    TEXTOID, -1, 0);
6393                 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
6394                                                    TEXTOID, -1, 0);
6395                 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "unit",
6396                                                    TEXTOID, -1, 0);
6397                 TupleDescInitEntry(tupdesc, (AttrNumber) 4, "category",
6398                                                    TEXTOID, -1, 0);
6399                 TupleDescInitEntry(tupdesc, (AttrNumber) 5, "short_desc",
6400                                                    TEXTOID, -1, 0);
6401                 TupleDescInitEntry(tupdesc, (AttrNumber) 6, "extra_desc",
6402                                                    TEXTOID, -1, 0);
6403                 TupleDescInitEntry(tupdesc, (AttrNumber) 7, "context",
6404                                                    TEXTOID, -1, 0);
6405                 TupleDescInitEntry(tupdesc, (AttrNumber) 8, "vartype",
6406                                                    TEXTOID, -1, 0);
6407                 TupleDescInitEntry(tupdesc, (AttrNumber) 9, "source",
6408                                                    TEXTOID, -1, 0);
6409                 TupleDescInitEntry(tupdesc, (AttrNumber) 10, "min_val",
6410                                                    TEXTOID, -1, 0);
6411                 TupleDescInitEntry(tupdesc, (AttrNumber) 11, "max_val",
6412                                                    TEXTOID, -1, 0);
6413                 TupleDescInitEntry(tupdesc, (AttrNumber) 12, "enumvals",
6414                                                    TEXTARRAYOID, -1, 0);
6415                 TupleDescInitEntry(tupdesc, (AttrNumber) 13, "boot_val",
6416                                                    TEXTOID, -1, 0);
6417                 TupleDescInitEntry(tupdesc, (AttrNumber) 14, "reset_val",
6418                                                    TEXTOID, -1, 0);
6419                 TupleDescInitEntry(tupdesc, (AttrNumber) 15, "sourcefile",
6420                                                    TEXTOID, -1, 0);
6421                 TupleDescInitEntry(tupdesc, (AttrNumber) 16, "sourceline",
6422                                                    INT4OID, -1, 0);
6423
6424                 /*
6425                  * Generate attribute metadata needed later to produce tuples from raw
6426                  * C strings
6427                  */
6428                 attinmeta = TupleDescGetAttInMetadata(tupdesc);
6429                 funcctx->attinmeta = attinmeta;
6430
6431                 /* total number of tuples to be returned */
6432                 funcctx->max_calls = GetNumConfigOptions();
6433
6434                 MemoryContextSwitchTo(oldcontext);
6435         }
6436
6437         /* stuff done on every call of the function */
6438         funcctx = SRF_PERCALL_SETUP();
6439
6440         call_cntr = funcctx->call_cntr;
6441         max_calls = funcctx->max_calls;
6442         attinmeta = funcctx->attinmeta;
6443
6444         if (call_cntr < max_calls)      /* do when there is more left to send */
6445         {
6446                 char       *values[NUM_PG_SETTINGS_ATTS];
6447                 bool            noshow;
6448                 HeapTuple       tuple;
6449                 Datum           result;
6450
6451                 /*
6452                  * Get the next visible GUC variable name and value
6453                  */
6454                 do
6455                 {
6456                         GetConfigOptionByNum(call_cntr, (const char **) values, &noshow);
6457                         if (noshow)
6458                         {
6459                                 /* bump the counter and get the next config setting */
6460                                 call_cntr = ++funcctx->call_cntr;
6461
6462                                 /* make sure we haven't gone too far now */
6463                                 if (call_cntr >= max_calls)
6464                                         SRF_RETURN_DONE(funcctx);
6465                         }
6466                 } while (noshow);
6467
6468                 /* build a tuple */
6469                 tuple = BuildTupleFromCStrings(attinmeta, values);
6470
6471                 /* make the tuple into a datum */
6472                 result = HeapTupleGetDatum(tuple);
6473
6474                 SRF_RETURN_NEXT(funcctx, result);
6475         }
6476         else
6477         {
6478                 /* do when there is no more left */
6479                 SRF_RETURN_DONE(funcctx);
6480         }
6481 }
6482
6483 static char *
6484 _ShowOption(struct config_generic * record, bool use_units)
6485 {
6486         char            buffer[256];
6487         const char *val;
6488
6489         switch (record->vartype)
6490         {
6491                 case PGC_BOOL:
6492                         {
6493                                 struct config_bool *conf = (struct config_bool *) record;
6494
6495                                 if (conf->show_hook)
6496                                         val = (*conf->show_hook) ();
6497                                 else
6498                                         val = *conf->variable ? "on" : "off";
6499                         }
6500                         break;
6501
6502                 case PGC_INT:
6503                         {
6504                                 struct config_int *conf = (struct config_int *) record;
6505
6506                                 if (conf->show_hook)
6507                                         val = (*conf->show_hook) ();
6508                                 else
6509                                 {
6510                                         /*
6511                                          * Use int64 arithmetic to avoid overflows in units
6512                                          * conversion.  If INT64_IS_BUSTED we might overflow
6513                                          * anyway and print bogus answers, but there are few
6514                                          * enough such machines that it doesn't seem worth trying
6515                                          * harder.
6516                                          */
6517                                         int64           result = *conf->variable;
6518                                         const char *unit;
6519
6520                                         if (use_units && result > 0 &&
6521                                                 (record->flags & GUC_UNIT_MEMORY))
6522                                         {
6523                                                 switch (record->flags & GUC_UNIT_MEMORY)
6524                                                 {
6525                                                         case GUC_UNIT_BLOCKS:
6526                                                                 result *= BLCKSZ / 1024;
6527                                                                 break;
6528                                                         case GUC_UNIT_XBLOCKS:
6529                                                                 result *= XLOG_BLCKSZ / 1024;
6530                                                                 break;
6531                                                 }
6532
6533                                                 if (result % KB_PER_GB == 0)
6534                                                 {
6535                                                         result /= KB_PER_GB;
6536                                                         unit = "GB";
6537                                                 }
6538                                                 else if (result % KB_PER_MB == 0)
6539                                                 {
6540                                                         result /= KB_PER_MB;
6541                                                         unit = "MB";
6542                                                 }
6543                                                 else
6544                                                 {
6545                                                         unit = "kB";
6546                                                 }
6547                                         }
6548                                         else if (use_units && result > 0 &&
6549                                                          (record->flags & GUC_UNIT_TIME))
6550                                         {
6551                                                 switch (record->flags & GUC_UNIT_TIME)
6552                                                 {
6553                                                         case GUC_UNIT_S:
6554                                                                 result *= MS_PER_S;
6555                                                                 break;
6556                                                         case GUC_UNIT_MIN:
6557                                                                 result *= MS_PER_MIN;
6558                                                                 break;
6559                                                 }
6560
6561                                                 if (result % MS_PER_D == 0)
6562                                                 {
6563                                                         result /= MS_PER_D;
6564                                                         unit = "d";
6565                                                 }
6566                                                 else if (result % MS_PER_H == 0)
6567                                                 {
6568                                                         result /= MS_PER_H;
6569                                                         unit = "h";
6570                                                 }
6571                                                 else if (result % MS_PER_MIN == 0)
6572                                                 {
6573                                                         result /= MS_PER_MIN;
6574                                                         unit = "min";
6575                                                 }
6576                                                 else if (result % MS_PER_S == 0)
6577                                                 {
6578                                                         result /= MS_PER_S;
6579                                                         unit = "s";
6580                                                 }
6581                                                 else
6582                                                 {
6583                                                         unit = "ms";
6584                                                 }
6585                                         }
6586                                         else
6587                                                 unit = "";
6588
6589                                         snprintf(buffer, sizeof(buffer), INT64_FORMAT "%s",
6590                                                          result, unit);
6591                                         val = buffer;
6592                                 }
6593                         }
6594                         break;
6595
6596                 case PGC_REAL:
6597                         {
6598                                 struct config_real *conf = (struct config_real *) record;
6599
6600                                 if (conf->show_hook)
6601                                         val = (*conf->show_hook) ();
6602                                 else
6603                                 {
6604                                         snprintf(buffer, sizeof(buffer), "%g",
6605                                                          *conf->variable);
6606                                         val = buffer;
6607                                 }
6608                         }
6609                         break;
6610
6611                 case PGC_STRING:
6612                         {
6613                                 struct config_string *conf = (struct config_string *) record;
6614
6615                                 if (conf->show_hook)
6616                                         val = (*conf->show_hook) ();
6617                                 else if (*conf->variable && **conf->variable)
6618                                         val = *conf->variable;
6619                                 else
6620                                         val = "";
6621                         }
6622                         break;
6623
6624                 case PGC_ENUM:
6625                         {
6626                                 struct config_enum *conf = (struct config_enum *) record;
6627
6628                                 if (conf->show_hook)
6629                                         val = (*conf->show_hook) ();
6630                                 else
6631                                         val = config_enum_lookup_by_value(conf, *conf->variable);
6632                         }
6633                         break;
6634
6635                 default:
6636                         /* just to keep compiler quiet */
6637                         val = "???";
6638                         break;
6639         }
6640
6641         return pstrdup(val);
6642 }
6643
6644
6645 /*
6646  * Attempt (badly) to detect if a proposed new GUC setting is the same
6647  * as the current value.
6648  *
6649  * XXX this does not really work because it doesn't account for the
6650  * effects of canonicalization of string values by assign_hooks.
6651  */
6652 static bool
6653 is_newvalue_equal(struct config_generic * record, const char *newvalue)
6654 {
6655         /* newvalue == NULL isn't supported */
6656         Assert(newvalue != NULL);
6657
6658         switch (record->vartype)
6659         {
6660                 case PGC_BOOL:
6661                         {
6662                                 struct config_bool *conf = (struct config_bool *) record;
6663                                 bool            newval;
6664
6665                                 return parse_bool(newvalue, &newval)
6666                                         && *conf->variable == newval;
6667                         }
6668                 case PGC_INT:
6669                         {
6670                                 struct config_int *conf = (struct config_int *) record;
6671                                 int                     newval;
6672
6673                                 return parse_int(newvalue, &newval, record->flags, NULL)
6674                                         && *conf->variable == newval;
6675                         }
6676                 case PGC_REAL:
6677                         {
6678                                 struct config_real *conf = (struct config_real *) record;
6679                                 double          newval;
6680
6681                                 return parse_real(newvalue, &newval)
6682                                         && *conf->variable == newval;
6683                         }
6684                 case PGC_STRING:
6685                         {
6686                                 struct config_string *conf = (struct config_string *) record;
6687
6688                                 return *conf->variable != NULL &&
6689                                         strcmp(*conf->variable, newvalue) == 0;
6690                         }
6691
6692                 case PGC_ENUM:
6693                         {
6694                                 struct config_enum *conf = (struct config_enum *) record;
6695                                 int                     newval;
6696
6697                                 return config_enum_lookup_by_name(conf, newvalue, &newval) &&
6698                                         *conf->variable == newval;
6699                         }
6700         }
6701
6702         return false;
6703 }
6704
6705
6706 #ifdef EXEC_BACKEND
6707
6708 /*
6709  *      These routines dump out all non-default GUC options into a binary
6710  *      file that is read by all exec'ed backends.  The format is:
6711  *
6712  *              variable name, string, null terminated
6713  *              variable value, string, null terminated
6714  *              variable source, integer
6715  */
6716 static void
6717 write_one_nondefault_variable(FILE *fp, struct config_generic * gconf)
6718 {
6719         if (gconf->source == PGC_S_DEFAULT)
6720                 return;
6721
6722         fprintf(fp, "%s", gconf->name);
6723         fputc(0, fp);
6724
6725         switch (gconf->vartype)
6726         {
6727                 case PGC_BOOL:
6728                         {
6729                                 struct config_bool *conf = (struct config_bool *) gconf;
6730
6731                                 if (*conf->variable)
6732                                         fprintf(fp, "true");
6733                                 else
6734                                         fprintf(fp, "false");
6735                         }
6736                         break;
6737
6738                 case PGC_INT:
6739                         {
6740                                 struct config_int *conf = (struct config_int *) gconf;
6741
6742                                 fprintf(fp, "%d", *conf->variable);
6743                         }
6744                         break;
6745
6746                 case PGC_REAL:
6747                         {
6748                                 struct config_real *conf = (struct config_real *) gconf;
6749
6750                                 /* Could lose precision here? */
6751                                 fprintf(fp, "%f", *conf->variable);
6752                         }
6753                         break;
6754
6755                 case PGC_STRING:
6756                         {
6757                                 struct config_string *conf = (struct config_string *) gconf;
6758
6759                                 fprintf(fp, "%s", *conf->variable);
6760                         }
6761                         break;
6762
6763                 case PGC_ENUM:
6764                         {
6765                                 struct config_enum *conf = (struct config_enum *) gconf;
6766
6767                                 fprintf(fp, "%s",
6768                                                 config_enum_lookup_by_value(conf, *conf->variable));
6769                         }
6770                         break;
6771         }
6772
6773         fputc(0, fp);
6774
6775         fwrite(&gconf->source, sizeof(gconf->source), 1, fp);
6776 }
6777
6778 void
6779 write_nondefault_variables(GucContext context)
6780 {
6781         int                     elevel;
6782         FILE       *fp;
6783         struct config_generic *cvc_conf;
6784         int                     i;
6785
6786         Assert(context == PGC_POSTMASTER || context == PGC_SIGHUP);
6787
6788         elevel = (context == PGC_SIGHUP) ? LOG : ERROR;
6789
6790         /*
6791          * Open file
6792          */
6793         fp = AllocateFile(CONFIG_EXEC_PARAMS_NEW, "w");
6794         if (!fp)
6795         {
6796                 ereport(elevel,
6797                                 (errcode_for_file_access(),
6798                                  errmsg("could not write to file \"%s\": %m",
6799                                                 CONFIG_EXEC_PARAMS_NEW)));
6800                 return;
6801         }
6802
6803         /*
6804          * custom_variable_classes must be written out first; otherwise we might
6805          * reject custom variable values while reading the file.
6806          */
6807         cvc_conf = find_option("custom_variable_classes", false, ERROR);
6808         if (cvc_conf)
6809                 write_one_nondefault_variable(fp, cvc_conf);
6810
6811         for (i = 0; i < num_guc_variables; i++)
6812         {
6813                 struct config_generic *gconf = guc_variables[i];
6814
6815                 if (gconf != cvc_conf)
6816                         write_one_nondefault_variable(fp, gconf);
6817         }
6818
6819         if (FreeFile(fp))
6820         {
6821                 ereport(elevel,
6822                                 (errcode_for_file_access(),
6823                                  errmsg("could not write to file \"%s\": %m",
6824                                                 CONFIG_EXEC_PARAMS_NEW)));
6825                 return;
6826         }
6827
6828         /*
6829          * Put new file in place.  This could delay on Win32, but we don't hold
6830          * any exclusive locks.
6831          */
6832         rename(CONFIG_EXEC_PARAMS_NEW, CONFIG_EXEC_PARAMS);
6833 }
6834
6835
6836 /*
6837  *      Read string, including null byte from file
6838  *
6839  *      Return NULL on EOF and nothing read
6840  */
6841 static char *
6842 read_string_with_null(FILE *fp)
6843 {
6844         int                     i = 0,
6845                                 ch,
6846                                 maxlen = 256;
6847         char       *str = NULL;
6848
6849         do
6850         {
6851                 if ((ch = fgetc(fp)) == EOF)
6852                 {
6853                         if (i == 0)
6854                                 return NULL;
6855                         else
6856                                 elog(FATAL, "invalid format of exec config params file");
6857                 }
6858                 if (i == 0)
6859                         str = guc_malloc(FATAL, maxlen);
6860                 else if (i == maxlen)
6861                         str = guc_realloc(FATAL, str, maxlen *= 2);
6862                 str[i++] = ch;
6863         } while (ch != 0);
6864
6865         return str;
6866 }
6867
6868
6869 /*
6870  *      This routine loads a previous postmaster dump of its non-default
6871  *      settings.
6872  */
6873 void
6874 read_nondefault_variables(void)
6875 {
6876         FILE       *fp;
6877         char       *varname,
6878                            *varvalue;
6879         int                     varsource;
6880
6881         /*
6882          * Open file
6883          */
6884         fp = AllocateFile(CONFIG_EXEC_PARAMS, "r");
6885         if (!fp)
6886         {
6887                 /* File not found is fine */
6888                 if (errno != ENOENT)
6889                         ereport(FATAL,
6890                                         (errcode_for_file_access(),
6891                                          errmsg("could not read from file \"%s\": %m",
6892                                                         CONFIG_EXEC_PARAMS)));
6893                 return;
6894         }
6895
6896         for (;;)
6897         {
6898                 struct config_generic *record;
6899
6900                 if ((varname = read_string_with_null(fp)) == NULL)
6901                         break;
6902
6903                 if ((record = find_option(varname, true, FATAL)) == NULL)
6904                         elog(FATAL, "failed to locate variable %s in exec config params file", varname);
6905                 if ((varvalue = read_string_with_null(fp)) == NULL)
6906                         elog(FATAL, "invalid format of exec config params file");
6907                 if (fread(&varsource, sizeof(varsource), 1, fp) == 0)
6908                         elog(FATAL, "invalid format of exec config params file");
6909
6910                 (void) set_config_option(varname, varvalue, record->context,
6911                                                                  varsource, GUC_ACTION_SET, true);
6912                 free(varname);
6913                 free(varvalue);
6914         }
6915
6916         FreeFile(fp);
6917 }
6918 #endif   /* EXEC_BACKEND */
6919
6920
6921 /*
6922  * A little "long argument" simulation, although not quite GNU
6923  * compliant. Takes a string of the form "some-option=some value" and
6924  * returns name = "some_option" and value = "some value" in malloc'ed
6925  * storage. Note that '-' is converted to '_' in the option name. If
6926  * there is no '=' in the input string then value will be NULL.
6927  */
6928 void
6929 ParseLongOption(const char *string, char **name, char **value)
6930 {
6931         size_t          equal_pos;
6932         char       *cp;
6933
6934         AssertArg(string);
6935         AssertArg(name);
6936         AssertArg(value);
6937
6938         equal_pos = strcspn(string, "=");
6939
6940         if (string[equal_pos] == '=')
6941         {
6942                 *name = guc_malloc(FATAL, equal_pos + 1);
6943                 strlcpy(*name, string, equal_pos + 1);
6944
6945                 *value = guc_strdup(FATAL, &string[equal_pos + 1]);
6946         }
6947         else
6948         {
6949                 /* no equal sign in string */
6950                 *name = guc_strdup(FATAL, string);
6951                 *value = NULL;
6952         }
6953
6954         for (cp = *name; *cp; cp++)
6955                 if (*cp == '-')
6956                         *cp = '_';
6957 }
6958
6959
6960 /*
6961  * Handle options fetched from pg_database.datconfig, pg_authid.rolconfig,
6962  * pg_proc.proconfig, etc.      Caller must specify proper context/source/action.
6963  *
6964  * The array parameter must be an array of TEXT (it must not be NULL).
6965  */
6966 void
6967 ProcessGUCArray(ArrayType *array,
6968                                 GucContext context, GucSource source, GucAction action)
6969 {
6970         int                     i;
6971
6972         Assert(array != NULL);
6973         Assert(ARR_ELEMTYPE(array) == TEXTOID);
6974         Assert(ARR_NDIM(array) == 1);
6975         Assert(ARR_LBOUND(array)[0] == 1);
6976
6977         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
6978         {
6979                 Datum           d;
6980                 bool            isnull;
6981                 char       *s;
6982                 char       *name;
6983                 char       *value;
6984
6985                 d = array_ref(array, 1, &i,
6986                                           -1 /* varlenarray */ ,
6987                                           -1 /* TEXT's typlen */ ,
6988                                           false /* TEXT's typbyval */ ,
6989                                           'i' /* TEXT's typalign */ ,
6990                                           &isnull);
6991
6992                 if (isnull)
6993                         continue;
6994
6995                 s = TextDatumGetCString(d);
6996
6997                 ParseLongOption(s, &name, &value);
6998                 if (!value)
6999                 {
7000                         ereport(WARNING,
7001                                         (errcode(ERRCODE_SYNTAX_ERROR),
7002                                          errmsg("could not parse setting for parameter \"%s\"",
7003                                                         name)));
7004                         free(name);
7005                         continue;
7006                 }
7007
7008                 (void) set_config_option(name, value, context, source, action, true);
7009
7010                 free(name);
7011                 if (value)
7012                         free(value);
7013         }
7014 }
7015
7016
7017 /*
7018  * Add an entry to an option array.  The array parameter may be NULL
7019  * to indicate the current table entry is NULL.
7020  */
7021 ArrayType *
7022 GUCArrayAdd(ArrayType *array, const char *name, const char *value)
7023 {
7024         const char *varname;
7025         Datum           datum;
7026         char       *newval;
7027         ArrayType  *a;
7028
7029         Assert(name);
7030         Assert(value);
7031
7032         /* test if the option is valid */
7033         set_config_option(name, value,
7034                                           superuser() ? PGC_SUSET : PGC_USERSET,
7035                                           PGC_S_TEST, GUC_ACTION_SET, false);
7036
7037         /* convert name to canonical spelling, so we can use plain strcmp */
7038         (void) GetConfigOptionByName(name, &varname);
7039         name = varname;
7040
7041         newval = palloc(strlen(name) + 1 + strlen(value) + 1);
7042         sprintf(newval, "%s=%s", name, value);
7043         datum = CStringGetTextDatum(newval);
7044
7045         if (array)
7046         {
7047                 int                     index;
7048                 bool            isnull;
7049                 int                     i;
7050
7051                 Assert(ARR_ELEMTYPE(array) == TEXTOID);
7052                 Assert(ARR_NDIM(array) == 1);
7053                 Assert(ARR_LBOUND(array)[0] == 1);
7054
7055                 index = ARR_DIMS(array)[0] + 1; /* add after end */
7056
7057                 for (i = 1; i <= ARR_DIMS(array)[0]; i++)
7058                 {
7059                         Datum           d;
7060                         char       *current;
7061
7062                         d = array_ref(array, 1, &i,
7063                                                   -1 /* varlenarray */ ,
7064                                                   -1 /* TEXT's typlen */ ,
7065                                                   false /* TEXT's typbyval */ ,
7066                                                   'i' /* TEXT's typalign */ ,
7067                                                   &isnull);
7068                         if (isnull)
7069                                 continue;
7070                         current = TextDatumGetCString(d);
7071                         if (strncmp(current, newval, strlen(name) + 1) == 0)
7072                         {
7073                                 index = i;
7074                                 break;
7075                         }
7076                 }
7077
7078                 a = array_set(array, 1, &index,
7079                                           datum,
7080                                           false,
7081                                           -1 /* varlena array */ ,
7082                                           -1 /* TEXT's typlen */ ,
7083                                           false /* TEXT's typbyval */ ,
7084                                           'i' /* TEXT's typalign */ );
7085         }
7086         else
7087                 a = construct_array(&datum, 1,
7088                                                         TEXTOID,
7089                                                         -1, false, 'i');
7090
7091         return a;
7092 }
7093
7094
7095 /*
7096  * Delete an entry from an option array.  The array parameter may be NULL
7097  * to indicate the current table entry is NULL.  Also, if the return value
7098  * is NULL then a null should be stored.
7099  */
7100 ArrayType *
7101 GUCArrayDelete(ArrayType *array, const char *name)
7102 {
7103         const char *varname;
7104         ArrayType  *newarray;
7105         int                     i;
7106         int                     index;
7107
7108         Assert(name);
7109
7110         /* test if the option is valid */
7111         set_config_option(name, NULL,
7112                                           superuser() ? PGC_SUSET : PGC_USERSET,
7113                                           PGC_S_TEST, GUC_ACTION_SET, false);
7114
7115         /* convert name to canonical spelling, so we can use plain strcmp */
7116         (void) GetConfigOptionByName(name, &varname);
7117         name = varname;
7118
7119         /* if array is currently null, then surely nothing to delete */
7120         if (!array)
7121                 return NULL;
7122
7123         newarray = NULL;
7124         index = 1;
7125
7126         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
7127         {
7128                 Datum           d;
7129                 char       *val;
7130                 bool            isnull;
7131
7132                 d = array_ref(array, 1, &i,
7133                                           -1 /* varlenarray */ ,
7134                                           -1 /* TEXT's typlen */ ,
7135                                           false /* TEXT's typbyval */ ,
7136                                           'i' /* TEXT's typalign */ ,
7137                                           &isnull);
7138                 if (isnull)
7139                         continue;
7140                 val = TextDatumGetCString(d);
7141
7142                 /* ignore entry if it's what we want to delete */
7143                 if (strncmp(val, name, strlen(name)) == 0
7144                         && val[strlen(name)] == '=')
7145                         continue;
7146
7147                 /* else add it to the output array */
7148                 if (newarray)
7149                 {
7150                         newarray = array_set(newarray, 1, &index,
7151                                                                  d,
7152                                                                  false,
7153                                                                  -1 /* varlenarray */ ,
7154                                                                  -1 /* TEXT's typlen */ ,
7155                                                                  false /* TEXT's typbyval */ ,
7156                                                                  'i' /* TEXT's typalign */ );
7157                 }
7158                 else
7159                         newarray = construct_array(&d, 1,
7160                                                                            TEXTOID,
7161                                                                            -1, false, 'i');
7162
7163                 index++;
7164         }
7165
7166         return newarray;
7167 }
7168
7169
7170 /*
7171  * assign_hook and show_hook subroutines
7172  */
7173
7174 static const char *
7175 assign_log_destination(const char *value, bool doit, GucSource source)
7176 {
7177         char       *rawstring;
7178         List       *elemlist;
7179         ListCell   *l;
7180         int                     newlogdest = 0;
7181
7182         /* Need a modifiable copy of string */
7183         rawstring = pstrdup(value);
7184
7185         /* Parse string into list of identifiers */
7186         if (!SplitIdentifierString(rawstring, ',', &elemlist))
7187         {
7188                 /* syntax error in list */
7189                 pfree(rawstring);
7190                 list_free(elemlist);
7191                 ereport(GUC_complaint_elevel(source),
7192                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7193                    errmsg("invalid list syntax for parameter \"log_destination\"")));
7194                 return NULL;
7195         }
7196
7197         foreach(l, elemlist)
7198         {
7199                 char       *tok = (char *) lfirst(l);
7200
7201                 if (pg_strcasecmp(tok, "stderr") == 0)
7202                         newlogdest |= LOG_DESTINATION_STDERR;
7203                 else if (pg_strcasecmp(tok, "csvlog") == 0)
7204                         newlogdest |= LOG_DESTINATION_CSVLOG;
7205 #ifdef HAVE_SYSLOG
7206                 else if (pg_strcasecmp(tok, "syslog") == 0)
7207                         newlogdest |= LOG_DESTINATION_SYSLOG;
7208 #endif
7209 #ifdef WIN32
7210                 else if (pg_strcasecmp(tok, "eventlog") == 0)
7211                         newlogdest |= LOG_DESTINATION_EVENTLOG;
7212 #endif
7213                 else
7214                 {
7215                         ereport(GUC_complaint_elevel(source),
7216                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7217                                   errmsg("unrecognized \"log_destination\" key word: \"%s\"",
7218                                                  tok)));
7219                         pfree(rawstring);
7220                         list_free(elemlist);
7221                         return NULL;
7222                 }
7223         }
7224
7225         if (doit)
7226                 Log_destination = newlogdest;
7227
7228         pfree(rawstring);
7229         list_free(elemlist);
7230
7231         return value;
7232 }
7233
7234 #ifdef HAVE_SYSLOG
7235
7236 static bool
7237 assign_syslog_facility(int newval, bool doit, GucSource source)
7238 {
7239         if (doit)
7240                 set_syslog_parameters(syslog_ident_str ? syslog_ident_str : "postgres",
7241                                                           newval);
7242
7243         return true;
7244 }
7245
7246 static const char *
7247 assign_syslog_ident(const char *ident, bool doit, GucSource source)
7248 {
7249         if (doit)
7250                 set_syslog_parameters(ident, syslog_facility);
7251
7252         return ident;
7253 }
7254 #endif   /* HAVE_SYSLOG */
7255
7256
7257 static bool
7258 assign_session_replication_role(int newval, bool doit, GucSource source)
7259 {
7260         /*
7261          * Must flush the plan cache when changing replication role; but don't
7262          * flush unnecessarily.
7263          */
7264         if (doit && SessionReplicationRole != newval)
7265         {
7266                 ResetPlanCache();
7267         }
7268
7269         return true;
7270 }
7271
7272 static const char *
7273 show_num_temp_buffers(void)
7274 {
7275         /*
7276          * We show the GUC var until local buffers have been initialized, and
7277          * NLocBuffer afterwards.
7278          */
7279         static char nbuf[32];
7280
7281         sprintf(nbuf, "%d", NLocBuffer ? NLocBuffer : num_temp_buffers);
7282         return nbuf;
7283 }
7284
7285 static bool
7286 assign_phony_autocommit(bool newval, bool doit, GucSource source)
7287 {
7288         if (!newval)
7289         {
7290                 ereport(GUC_complaint_elevel(source),
7291                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
7292                                  errmsg("SET AUTOCOMMIT TO OFF is no longer supported")));
7293                 return false;
7294         }
7295         return true;
7296 }
7297
7298 static const char *
7299 assign_custom_variable_classes(const char *newval, bool doit, GucSource source)
7300 {
7301         /*
7302          * Check syntax. newval must be a comma separated list of identifiers.
7303          * Whitespace is allowed but removed from the result.
7304          */
7305         bool            hasSpaceAfterToken = false;
7306         const char *cp = newval;
7307         int                     symLen = 0;
7308         char            c;
7309         StringInfoData buf;
7310
7311         initStringInfo(&buf);
7312         while ((c = *cp++) != '\0')
7313         {
7314                 if (isspace((unsigned char) c))
7315                 {
7316                         if (symLen > 0)
7317                                 hasSpaceAfterToken = true;
7318                         continue;
7319                 }
7320
7321                 if (c == ',')
7322                 {
7323                         if (symLen > 0)         /* terminate identifier */
7324                         {
7325                                 appendStringInfoChar(&buf, ',');
7326                                 symLen = 0;
7327                         }
7328                         hasSpaceAfterToken = false;
7329                         continue;
7330                 }
7331
7332                 if (hasSpaceAfterToken || !(isalnum((unsigned char) c) || c == '_'))
7333                 {
7334                         /*
7335                          * Syntax error due to token following space after token or
7336                          * non-identifier character
7337                          */
7338                         pfree(buf.data);
7339                         return NULL;
7340                 }
7341                 appendStringInfoChar(&buf, c);
7342                 symLen++;
7343         }
7344
7345         /* Remove stray ',' at end */
7346         if (symLen == 0 && buf.len > 0)
7347                 buf.data[--buf.len] = '\0';
7348
7349         /* GUC wants the result malloc'd */
7350         newval = guc_strdup(LOG, buf.data);
7351
7352         pfree(buf.data);
7353         return newval;
7354 }
7355
7356 static bool
7357 assign_debug_assertions(bool newval, bool doit, GucSource source)
7358 {
7359 #ifndef USE_ASSERT_CHECKING
7360         if (newval)
7361         {
7362                 ereport(GUC_complaint_elevel(source),
7363                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7364                            errmsg("assertion checking is not supported by this build")));
7365                 return false;
7366         }
7367 #endif
7368         return true;
7369 }
7370
7371 static bool
7372 assign_ssl(bool newval, bool doit, GucSource source)
7373 {
7374 #ifndef USE_SSL
7375         if (newval)
7376         {
7377                 ereport(GUC_complaint_elevel(source),
7378                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7379                                  errmsg("SSL is not supported by this build")));
7380                 return false;
7381         }
7382 #endif
7383         return true;
7384 }
7385
7386 static bool
7387 assign_stage_log_stats(bool newval, bool doit, GucSource source)
7388 {
7389         if (newval && log_statement_stats)
7390         {
7391                 ereport(GUC_complaint_elevel(source),
7392                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7393                                  errmsg("cannot enable parameter when \"log_statement_stats\" is true")));
7394                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7395                 if (source != PGC_S_OVERRIDE)
7396                         return false;
7397         }
7398         return true;
7399 }
7400
7401 static bool
7402 assign_log_stats(bool newval, bool doit, GucSource source)
7403 {
7404         if (newval &&
7405                 (log_parser_stats || log_planner_stats || log_executor_stats))
7406         {
7407                 ereport(GUC_complaint_elevel(source),
7408                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7409                                  errmsg("cannot enable \"log_statement_stats\" when "
7410                                                 "\"log_parser_stats\", \"log_planner_stats\", "
7411                                                 "or \"log_executor_stats\" is true")));
7412                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7413                 if (source != PGC_S_OVERRIDE)
7414                         return false;
7415         }
7416         return true;
7417 }
7418
7419 static bool
7420 assign_transaction_read_only(bool newval, bool doit, GucSource source)
7421 {
7422         /* Can't go to r/w mode inside a r/o transaction */
7423         if (newval == false && XactReadOnly && IsSubTransaction())
7424         {
7425                 ereport(GUC_complaint_elevel(source),
7426                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7427                                  errmsg("cannot set transaction read-write mode inside a read-only transaction")));
7428                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7429                 if (source != PGC_S_OVERRIDE)
7430                         return false;
7431         }
7432         return true;
7433 }
7434
7435 static const char *
7436 assign_canonical_path(const char *newval, bool doit, GucSource source)
7437 {
7438         if (doit)
7439         {
7440                 char       *canon_val = guc_strdup(ERROR, newval);
7441
7442                 canonicalize_path(canon_val);
7443                 return canon_val;
7444         }
7445         else
7446                 return newval;
7447 }
7448
7449 static const char *
7450 assign_timezone_abbreviations(const char *newval, bool doit, GucSource source)
7451 {
7452         /*
7453          * The powerup value shown above for timezone_abbreviations is "UNKNOWN".
7454          * When we see this we just do nothing.  If this value isn't overridden
7455          * from the config file then pg_timezone_abbrev_initialize() will
7456          * eventually replace it with "Default".  This hack has two purposes: to
7457          * avoid wasting cycles loading values that might soon be overridden from
7458          * the config file, and to avoid trying to read the timezone abbrev files
7459          * during InitializeGUCOptions().  The latter doesn't work in an
7460          * EXEC_BACKEND subprocess because my_exec_path hasn't been set yet and so
7461          * we can't locate PGSHAREDIR.  (Essentially the same hack is used to
7462          * delay initializing TimeZone ... if we have any more, we should try to
7463          * clean up and centralize this mechanism ...)
7464          */
7465         if (strcmp(newval, "UNKNOWN") == 0)
7466         {
7467                 return newval;
7468         }
7469
7470         /* Loading abbrev file is expensive, so only do it when value changes */
7471         if (timezone_abbreviations_string == NULL ||
7472                 strcmp(timezone_abbreviations_string, newval) != 0)
7473         {
7474                 int                     elevel;
7475
7476                 /*
7477                  * If reading config file, only the postmaster should bleat loudly
7478                  * about problems.      Otherwise, it's just this one process doing it,
7479                  * and we use WARNING message level.
7480                  */
7481                 if (source == PGC_S_FILE)
7482                         elevel = IsUnderPostmaster ? DEBUG3 : LOG;
7483                 else
7484                         elevel = WARNING;
7485                 if (!load_tzoffsets(newval, doit, elevel))
7486                         return NULL;
7487         }
7488         return newval;
7489 }
7490
7491 /*
7492  * pg_timezone_abbrev_initialize --- set default value if not done already
7493  *
7494  * This is called after initial loading of postgresql.conf.  If no
7495  * timezone_abbreviations setting was found therein, select default.
7496  */
7497 void
7498 pg_timezone_abbrev_initialize(void)
7499 {
7500         if (strcmp(timezone_abbreviations_string, "UNKNOWN") == 0)
7501         {
7502                 SetConfigOption("timezone_abbreviations", "Default",
7503                                                 PGC_POSTMASTER, PGC_S_ARGV);
7504         }
7505 }
7506
7507 static const char *
7508 show_archive_command(void)
7509 {
7510         if (XLogArchiveMode)
7511                 return XLogArchiveCommand;
7512         else
7513                 return "(disabled)";
7514 }
7515
7516 static bool
7517 assign_tcp_keepalives_idle(int newval, bool doit, GucSource source)
7518 {
7519         if (doit)
7520                 return (pq_setkeepalivesidle(newval, MyProcPort) == STATUS_OK);
7521
7522         return true;
7523 }
7524
7525 static const char *
7526 show_tcp_keepalives_idle(void)
7527 {
7528         static char nbuf[16];
7529
7530         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesidle(MyProcPort));
7531         return nbuf;
7532 }
7533
7534 static bool
7535 assign_tcp_keepalives_interval(int newval, bool doit, GucSource source)
7536 {
7537         if (doit)
7538                 return (pq_setkeepalivesinterval(newval, MyProcPort) == STATUS_OK);
7539
7540         return true;
7541 }
7542
7543 static const char *
7544 show_tcp_keepalives_interval(void)
7545 {
7546         static char nbuf[16];
7547
7548         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesinterval(MyProcPort));
7549         return nbuf;
7550 }
7551
7552 static bool
7553 assign_tcp_keepalives_count(int newval, bool doit, GucSource source)
7554 {
7555         if (doit)
7556                 return (pq_setkeepalivescount(newval, MyProcPort) == STATUS_OK);
7557
7558         return true;
7559 }
7560
7561 static const char *
7562 show_tcp_keepalives_count(void)
7563 {
7564         static char nbuf[16];
7565
7566         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivescount(MyProcPort));
7567         return nbuf;
7568 }
7569
7570 static bool
7571 assign_maxconnections(int newval, bool doit, GucSource source)
7572 {
7573         if (newval + autovacuum_max_workers + 1 > INT_MAX / 4)
7574                 return false;
7575
7576         if (doit)
7577                 MaxBackends = newval + autovacuum_max_workers + 1;
7578
7579         return true;
7580 }
7581
7582 static bool
7583 assign_autovacuum_max_workers(int newval, bool doit, GucSource source)
7584 {
7585         if (MaxConnections + newval + 1 > INT_MAX / 4)
7586                 return false;
7587
7588         if (doit)
7589                 MaxBackends = MaxConnections + newval + 1;
7590
7591         return true;
7592 }
7593
7594 static bool
7595 assign_effective_io_concurrency(int newval, bool doit, GucSource source)
7596 {
7597 #ifdef USE_PREFETCH
7598         double          new_prefetch_pages = 0.0;
7599         int                     i;
7600
7601         /*----------
7602          * The user-visible GUC parameter is the number of drives (spindles),
7603          * which we need to translate to a number-of-pages-to-prefetch target.
7604          *
7605          * The expected number of prefetch pages needed to keep N drives busy is:
7606          *
7607          * drives |   I/O requests
7608          * -------+----------------
7609          *              1 |   1
7610          *              2 |   2/1 + 2/2 = 3
7611          *              3 |   3/1 + 3/2 + 3/3 = 5 1/2
7612          *              4 |   4/1 + 4/2 + 4/3 + 4/4 = 8 1/3
7613          *              n |   n * H(n)
7614          *
7615          * This is called the "coupon collector problem" and H(n) is called the
7616          * harmonic series.  This could be approximated by n * ln(n), but for
7617          * reasonable numbers of drives we might as well just compute the series.
7618          *
7619          * Alternatively we could set the target to the number of pages necessary
7620          * so that the expected number of active spindles is some arbitrary
7621          * percentage of the total.  This sounds the same but is actually slightly
7622          * different.  The result ends up being ln(1-P)/ln((n-1)/n) where P is
7623          * that desired fraction.
7624          *
7625          * Experimental results show that both of these formulas aren't aggressive
7626          * enough, but we don't really have any better proposals.
7627          *
7628          * Note that if newval = 0 (disabled), we must set target = 0.
7629          *----------
7630          */
7631
7632         for (i = 1; i <= newval; i++)
7633                 new_prefetch_pages += (double) newval / (double) i;
7634
7635         /* This range check shouldn't fail, but let's be paranoid */
7636         if (new_prefetch_pages >= 0.0 && new_prefetch_pages < (double) INT_MAX)
7637         {
7638                 if (doit)
7639                         target_prefetch_pages = (int) rint(new_prefetch_pages);
7640                 return true;
7641         }
7642         else
7643                 return false;
7644 #else
7645         return true;
7646 #endif   /* USE_PREFETCH */
7647 }
7648
7649 static const char *
7650 assign_pgstat_temp_directory(const char *newval, bool doit, GucSource source)
7651 {
7652         if (doit)
7653         {
7654                 char       *canon_val = guc_strdup(ERROR, newval);
7655                 char       *tname;
7656                 char       *fname;
7657
7658                 canonicalize_path(canon_val);
7659
7660                 tname = guc_malloc(ERROR, strlen(canon_val) + 12);              /* /pgstat.tmp */
7661                 sprintf(tname, "%s/pgstat.tmp", canon_val);
7662                 fname = guc_malloc(ERROR, strlen(canon_val) + 13);              /* /pgstat.stat */
7663                 sprintf(fname, "%s/pgstat.stat", canon_val);
7664
7665                 if (pgstat_stat_tmpname)
7666                         free(pgstat_stat_tmpname);
7667                 pgstat_stat_tmpname = tname;
7668                 if (pgstat_stat_filename)
7669                         free(pgstat_stat_filename);
7670                 pgstat_stat_filename = fname;
7671
7672                 return canon_val;
7673         }
7674         else
7675                 return newval;
7676 }
7677
7678 #include "guc-file.c"