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 1.508 2009/07/16 20:55:44 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/guc_tables.h"
  65 #include "utils/memutils.h"
  66 #include "utils/pg_locale.h"
  67 #include "utils/plancache.h"
  68 #include "utils/portal.h"
  69 #include "utils/ps_status.h"
  70 #include "utils/tzparser.h"
  71 #include "utils/xml.h"
  72
  73 #ifndef PG_KRB_SRVTAB
  74 #define PG_KRB_SRVTAB ""
  75 #endif
  76 #ifndef PG_KRB_SRVNAM
  77 #define PG_KRB_SRVNAM ""
  78 #endif
  79
  80 #define CONFIG_FILENAME "postgresql.conf"
  81 #define HBA_FILENAME    "pg_hba.conf"
  82 #define IDENT_FILENAME  "pg_ident.conf"
  83
  84 #ifdef EXEC_BACKEND
  85 #define CONFIG_EXEC_PARAMS "global/config_exec_params"
  86 #define CONFIG_EXEC_PARAMS_NEW "global/config_exec_params.new"
  87 #endif
  88
  89 /* upper limit for GUC variables measured in kilobytes of memory */
  90 #if SIZEOF_SIZE_T > 4
  91 #define MAX_KILOBYTES   INT_MAX
  92 #else
  93 #define MAX_KILOBYTES   (INT_MAX / 1024)
  94 #endif
  95
  96 #define KB_PER_MB (1024)
  97 #define KB_PER_GB (1024*1024)
  98
  99 #define MS_PER_S 1000
 100 #define S_PER_MIN 60
 101 #define MS_PER_MIN (1000 * 60)
 102 #define MIN_PER_H 60
 103 #define S_PER_H (60 * 60)
 104 #define MS_PER_H (1000 * 60 * 60)
 105 #define MIN_PER_D (60 * 24)
 106 #define S_PER_D (60 * 60 * 24)
 107 #define MS_PER_D (1000 * 60 * 60 * 24)
 108
 109 /* XXX these should appear in other modules' header files */
 110 extern bool Log_disconnections;
 111 extern int      CommitDelay;
 112 extern int      CommitSiblings;
 113 extern char *default_tablespace;
 114 extern char *temp_tablespaces;
 115 extern bool synchronize_seqscans;
 116 extern bool fullPageWrites;
 117
 118 #ifdef TRACE_SORT
 119 extern bool trace_sort;
 120 #endif
 121 #ifdef TRACE_SYNCSCAN
 122 extern bool trace_syncscan;
 123 #endif
 124 #ifdef DEBUG_BOUNDED_SORT
 125 extern bool optimize_bounded_sort;
 126 #endif
 127
 128 #ifdef USE_SSL
 129 extern char *SSLCipherSuites;
 130 #endif
 131
 132 static void set_config_sourcefile(const char *name, char *sourcefile,
 133                                           int sourceline);
 134
 135 static const char *assign_log_destination(const char *value,
 136                                            bool doit, GucSource source);
 137
 138 #ifdef HAVE_SYSLOG
 139 static int      syslog_facility = LOG_LOCAL0;
 140
 141 static bool assign_syslog_facility(int newval,
 142                                            bool doit, GucSource source);
 143 static const char *assign_syslog_ident(const char *ident,
 144                                         bool doit, GucSource source);
 145 #endif
 146
 147 static bool assign_session_replication_role(int newval, bool doit,
 148                                                                 GucSource source);
 149 static const char *show_num_temp_buffers(void);
 150 static bool assign_phony_autocommit(bool newval, bool doit, GucSource source);
 151 static const char *assign_custom_variable_classes(const char *newval, bool doit,
 152                                                            GucSource source);
 153 static bool assign_debug_assertions(bool newval, bool doit, GucSource source);
 154 static bool assign_ssl(bool newval, bool doit, GucSource source);
 155 static bool assign_stage_log_stats(bool newval, bool doit, GucSource source);
 156 static bool assign_log_stats(bool newval, bool doit, GucSource source);
 157 static bool assign_transaction_read_only(bool newval, bool doit, GucSource source);
 158 static const char *assign_canonical_path(const char *newval, bool doit, GucSource source);
 159 static const char *assign_timezone_abbreviations(const char *newval, bool doit, GucSource source);
 160 static const char *show_archive_command(void);
 161 static bool assign_tcp_keepalives_idle(int newval, bool doit, GucSource source);
 162 static bool assign_tcp_keepalives_interval(int newval, bool doit, GucSource source);
 163 static bool assign_tcp_keepalives_count(int newval, bool doit, GucSource source);
 164 static const char *show_tcp_keepalives_idle(void);
 165 static const char *show_tcp_keepalives_interval(void);
 166 static const char *show_tcp_keepalives_count(void);
 167 static bool assign_maxconnections(int newval, bool doit, GucSource source);
 168 static bool assign_autovacuum_max_workers(int newval, bool doit, GucSource source);
 169 static bool assign_effective_io_concurrency(int newval, bool doit, GucSource source);
 170 static const char *assign_pgstat_temp_directory(const char *newval, bool doit, GucSource source);
 171
 172 static char *config_enum_get_options(struct config_enum * record,
 173                                                 const char *prefix, const char *suffix,
 174                                                 const char *separator);
 175
 176
 177 /*
 178  * Options for enum values defined in this module.
 179  *
 180  * NOTE! Option values may not contain double quotes!
 181  */
 182
 183 /*
 184  * We have different sets for client and server message level options because
 185  * they sort slightly different (see "log" level)
 186  */
 187 static const struct config_enum_entry client_message_level_options[] = {
 188         {"debug", DEBUG2, true},
 189         {"debug5", DEBUG5, false},
 190         {"debug4", DEBUG4, false},
 191         {"debug3", DEBUG3, false},
 192         {"debug2", DEBUG2, false},
 193         {"debug1", DEBUG1, false},
 194         {"log", LOG, false},
 195         {"info", INFO, true},
 196         {"notice", NOTICE, false},
 197         {"warning", WARNING, false},
 198         {"error", ERROR, false},
 199         {"fatal", FATAL, true},
 200         {"panic", PANIC, true},
 201         {NULL, 0, false}
 202 };
 203
 204 static const struct config_enum_entry server_message_level_options[] = {
 205         {"debug", DEBUG2, true},
 206         {"debug5", DEBUG5, false},
 207         {"debug4", DEBUG4, false},
 208         {"debug3", DEBUG3, false},
 209         {"debug2", DEBUG2, false},
 210         {"debug1", DEBUG1, false},
 211         {"info", INFO, false},
 212         {"notice", NOTICE, false},
 213         {"warning", WARNING, false},
 214         {"error", ERROR, false},
 215         {"log", LOG, false},
 216         {"fatal", FATAL, false},
 217         {"panic", PANIC, false},
 218         {NULL, 0, false}
 219 };
 220
 221 static const struct config_enum_entry intervalstyle_options[] = {
 222         {"postgres", INTSTYLE_POSTGRES, false},
 223         {"postgres_verbose", INTSTYLE_POSTGRES_VERBOSE, false},
 224         {"sql_standard", INTSTYLE_SQL_STANDARD, false},
 225         {"iso_8601", INTSTYLE_ISO_8601, false},
 226         {NULL, 0, false}
 227 };
 228
 229 static const struct config_enum_entry log_error_verbosity_options[] = {
 230         {"terse", PGERROR_TERSE, false},
 231         {"default", PGERROR_DEFAULT, false},
 232         {"verbose", PGERROR_VERBOSE, false},
 233         {NULL, 0, false}
 234 };
 235
 236 static const struct config_enum_entry log_statement_options[] = {
 237         {"none", LOGSTMT_NONE, false},
 238         {"ddl", LOGSTMT_DDL, false},
 239         {"mod", LOGSTMT_MOD, false},
 240         {"all", LOGSTMT_ALL, false},
 241         {NULL, 0, false}
 242 };
 243
 244 static const struct config_enum_entry regex_flavor_options[] = {
 245         {"advanced", REG_ADVANCED, false},
 246         {"extended", REG_EXTENDED, false},
 247         {"basic", REG_BASIC, false},
 248         {NULL, 0, false}
 249 };
 250
 251 static const struct config_enum_entry isolation_level_options[] = {
 252         {"serializable", XACT_SERIALIZABLE, false},
 253         {"repeatable read", XACT_REPEATABLE_READ, false},
 254         {"read committed", XACT_READ_COMMITTED, false},
 255         {"read uncommitted", XACT_READ_UNCOMMITTED, false},
 256         {NULL, 0}
 257 };
 258
 259 static const struct config_enum_entry session_replication_role_options[] = {
 260         {"origin", SESSION_REPLICATION_ROLE_ORIGIN, false},
 261         {"replica", SESSION_REPLICATION_ROLE_REPLICA, false},
 262         {"local", SESSION_REPLICATION_ROLE_LOCAL, false},
 263         {NULL, 0, false}
 264 };
 265
 266 #ifdef HAVE_SYSLOG
 267 static const struct config_enum_entry syslog_facility_options[] = {
 268         {"local0", LOG_LOCAL0, false},
 269         {"local1", LOG_LOCAL1, false},
 270         {"local2", LOG_LOCAL2, false},
 271         {"local3", LOG_LOCAL3, false},
 272         {"local4", LOG_LOCAL4, false},
 273         {"local5", LOG_LOCAL5, false},
 274         {"local6", LOG_LOCAL6, false},
 275         {"local7", LOG_LOCAL7, false},
 276         {NULL, 0}
 277 };
 278 #endif
 279
 280 static const struct config_enum_entry track_function_options[] = {
 281         {"none", TRACK_FUNC_OFF, false},
 282         {"pl", TRACK_FUNC_PL, false},
 283         {"all", TRACK_FUNC_ALL, false},
 284         {NULL, 0, false}
 285 };
 286
 287 static const struct config_enum_entry xmlbinary_options[] = {
 288         {"base64", XMLBINARY_BASE64, false},
 289         {"hex", XMLBINARY_HEX, false},
 290         {NULL, 0, false}
 291 };
 292
 293 static const struct config_enum_entry xmloption_options[] = {
 294         {"content", XMLOPTION_CONTENT, false},
 295         {"document", XMLOPTION_DOCUMENT, false},
 296         {NULL, 0, false}
 297 };
 298
 299 /*
 300  * Although only "on", "off", and "safe_encoding" are documented, we
 301  * accept all the likely variants of "on" and "off".
 302  */
 303 static const struct config_enum_entry backslash_quote_options[] = {
 304         {"safe_encoding", BACKSLASH_QUOTE_SAFE_ENCODING, false},
 305         {"on", BACKSLASH_QUOTE_ON, false},
 306         {"off", BACKSLASH_QUOTE_OFF, false},
 307         {"true", BACKSLASH_QUOTE_ON, true},
 308         {"false", BACKSLASH_QUOTE_OFF, true},
 309         {"yes", BACKSLASH_QUOTE_ON, true},
 310         {"no", BACKSLASH_QUOTE_OFF, true},
 311         {"1", BACKSLASH_QUOTE_ON, true},
 312         {"0", BACKSLASH_QUOTE_OFF, true},
 313         {NULL, 0, false}
 314 };
 315
 316 /*
 317  * Although only "on", "off", and "partition" are documented, we
 318  * accept all the likely variants of "on" and "off".
 319  */
 320 static const struct config_enum_entry constraint_exclusion_options[] = {
 321         {"partition", CONSTRAINT_EXCLUSION_PARTITION, false},
 322         {"on", CONSTRAINT_EXCLUSION_ON, false},
 323         {"off", CONSTRAINT_EXCLUSION_OFF, false},
 324         {"true", CONSTRAINT_EXCLUSION_ON, true},
 325         {"false", CONSTRAINT_EXCLUSION_OFF, true},
 326         {"yes", CONSTRAINT_EXCLUSION_ON, true},
 327         {"no", CONSTRAINT_EXCLUSION_OFF, true},
 328         {"1", CONSTRAINT_EXCLUSION_ON, true},
 329         {"0", CONSTRAINT_EXCLUSION_OFF, true},
 330         {NULL, 0, false}
 331 };
 332
 333 /*
 334  * Options for enum values stored in other modules
 335  */
 336 extern const struct config_enum_entry sync_method_options[];
 337
 338 /*
 339  * GUC option variables that are exported from this module
 340  */
 341 #ifdef USE_ASSERT_CHECKING
 342 bool            assert_enabled = true;
 343 #else
 344 bool            assert_enabled = false;
 345 #endif
 346 bool            log_duration = false;
 347 bool            Debug_print_plan = false;
 348 bool            Debug_print_parse = false;
 349 bool            Debug_print_rewritten = false;
 350 bool            Debug_pretty_print = true;
 351
 352 bool            log_parser_stats = false;
 353 bool            log_planner_stats = false;
 354 bool            log_executor_stats = false;
 355 bool            log_statement_stats = false;            /* this is sort of all three
 356                                                                                                  * above together */
 357 bool            log_btree_build_stats = false;
 358
 359 bool            check_function_bodies = true;
 360 bool            default_with_oids = false;
 361 bool            SQL_inheritance = true;
 362
 363 bool            Password_encryption = true;
 364
 365 int                     log_min_error_statement = ERROR;
 366 int                     log_min_messages = WARNING;
 367 int                     client_min_messages = NOTICE;
 368 int                     log_min_duration_statement = -1;
 369 int                     log_temp_files = -1;
 370
 371 int                     num_temp_buffers = 1000;
 372
 373 char       *ConfigFileName;
 374 char       *HbaFileName;
 375 char       *IdentFileName;
 376 char       *external_pid_file;
 377
 378 char       *pgstat_temp_directory;
 379
 380 int                     tcp_keepalives_idle;
 381 int                     tcp_keepalives_interval;
 382 int                     tcp_keepalives_count;
 383
 384 /*
 385  * These variables are all dummies that don't do anything, except in some
 386  * cases provide the value for SHOW to display.  The real state is elsewhere
 387  * and is kept in sync by assign_hooks.
 388  */
 389 static char *log_destination_string;
 390
 391 #ifdef HAVE_SYSLOG
 392 static char *syslog_ident_str;
 393 #endif
 394 static bool phony_autocommit;
 395 static bool session_auth_is_superuser;
 396 static double phony_random_seed;
 397 static char *client_encoding_string;
 398 static char *datestyle_string;
 399 static char *locale_collate;
 400 static char *locale_ctype;
 401 static char *server_encoding_string;
 402 static char *server_version_string;
 403 static int      server_version_num;
 404 static char *timezone_string;
 405 static char *log_timezone_string;
 406 static char *timezone_abbreviations_string;
 407 static char *XactIsoLevel_string;
 408 static char *data_directory;
 409 static char *custom_variable_classes;
 410 static int      max_function_args;
 411 static int      max_index_keys;
 412 static int      max_identifier_length;
 413 static int      block_size;
 414 static int      segment_size;
 415 static int      wal_block_size;
 416 static int      wal_segment_size;
 417 static bool integer_datetimes;
 418 static int      effective_io_concurrency;
 419
 420 /* should be static, but commands/variable.c needs to get at these */
 421 char       *role_string;
 422 char       *session_authorization_string;
 423
 424
 425 /*
 426  * Displayable names for context types (enum GucContext)
 427  *
 428  * Note: these strings are deliberately not localized.
 429  */
 430 const char *const GucContext_Names[] =
 431 {
 432          /* PGC_INTERNAL */ "internal",
 433          /* PGC_POSTMASTER */ "postmaster",
 434          /* PGC_SIGHUP */ "sighup",
 435          /* PGC_BACKEND */ "backend",
 436          /* PGC_SUSET */ "superuser",
 437          /* PGC_USERSET */ "user"
 438 };
 439
 440 /*
 441  * Displayable names for source types (enum GucSource)
 442  *
 443  * Note: these strings are deliberately not localized.
 444  */
 445 const char *const GucSource_Names[] =
 446 {
 447          /* PGC_S_DEFAULT */ "default",
 448          /* PGC_S_ENV_VAR */ "environment variable",
 449          /* PGC_S_FILE */ "configuration file",
 450          /* PGC_S_ARGV */ "command line",
 451          /* PGC_S_DATABASE */ "database",
 452          /* PGC_S_USER */ "user",
 453          /* PGC_S_CLIENT */ "client",
 454          /* PGC_S_OVERRIDE */ "override",
 455          /* PGC_S_INTERACTIVE */ "interactive",
 456          /* PGC_S_TEST */ "test",
 457          /* PGC_S_SESSION */ "session"
 458 };
 459
 460 /*
 461  * Displayable names for the groupings defined in enum config_group
 462  */
 463 const char *const config_group_names[] =
 464 {
 465         /* UNGROUPED */
 466         gettext_noop("Ungrouped"),
 467         /* FILE_LOCATIONS */
 468         gettext_noop("File Locations"),
 469         /* CONN_AUTH */
 470         gettext_noop("Connections and Authentication"),
 471         /* CONN_AUTH_SETTINGS */
 472         gettext_noop("Connections and Authentication / Connection Settings"),
 473         /* CONN_AUTH_SECURITY */
 474         gettext_noop("Connections and Authentication / Security and Authentication"),
 475         /* RESOURCES */
 476         gettext_noop("Resource Usage"),
 477         /* RESOURCES_MEM */
 478         gettext_noop("Resource Usage / Memory"),
 479         /* RESOURCES_KERNEL */
 480         gettext_noop("Resource Usage / Kernel Resources"),
 481         /* WAL */
 482         gettext_noop("Write-Ahead Log"),
 483         /* WAL_SETTINGS */
 484         gettext_noop("Write-Ahead Log / Settings"),
 485         /* WAL_CHECKPOINTS */
 486         gettext_noop("Write-Ahead Log / Checkpoints"),
 487         /* QUERY_TUNING */
 488         gettext_noop("Query Tuning"),
 489         /* QUERY_TUNING_METHOD */
 490         gettext_noop("Query Tuning / Planner Method Configuration"),
 491         /* QUERY_TUNING_COST */
 492         gettext_noop("Query Tuning / Planner Cost Constants"),
 493         /* QUERY_TUNING_GEQO */
 494         gettext_noop("Query Tuning / Genetic Query Optimizer"),
 495         /* QUERY_TUNING_OTHER */
 496         gettext_noop("Query Tuning / Other Planner Options"),
 497         /* LOGGING */
 498         gettext_noop("Reporting and Logging"),
 499         /* LOGGING_WHERE */
 500         gettext_noop("Reporting and Logging / Where to Log"),
 501         /* LOGGING_WHEN */
 502         gettext_noop("Reporting and Logging / When to Log"),
 503         /* LOGGING_WHAT */
 504         gettext_noop("Reporting and Logging / What to Log"),
 505         /* STATS */
 506         gettext_noop("Statistics"),
 507         /* STATS_MONITORING */
 508         gettext_noop("Statistics / Monitoring"),
 509         /* STATS_COLLECTOR */
 510         gettext_noop("Statistics / Query and Index Statistics Collector"),
 511         /* AUTOVACUUM */
 512         gettext_noop("Autovacuum"),
 513         /* CLIENT_CONN */
 514         gettext_noop("Client Connection Defaults"),
 515         /* CLIENT_CONN_STATEMENT */
 516         gettext_noop("Client Connection Defaults / Statement Behavior"),
 517         /* CLIENT_CONN_LOCALE */
 518         gettext_noop("Client Connection Defaults / Locale and Formatting"),
 519         /* CLIENT_CONN_OTHER */
 520         gettext_noop("Client Connection Defaults / Other Defaults"),
 521         /* LOCK_MANAGEMENT */
 522         gettext_noop("Lock Management"),
 523         /* COMPAT_OPTIONS */
 524         gettext_noop("Version and Platform Compatibility"),
 525         /* COMPAT_OPTIONS_PREVIOUS */
 526         gettext_noop("Version and Platform Compatibility / Previous PostgreSQL Versions"),
 527         /* COMPAT_OPTIONS_CLIENT */
 528         gettext_noop("Version and Platform Compatibility / Other Platforms and Clients"),
 529         /* PRESET_OPTIONS */
 530         gettext_noop("Preset Options"),
 531         /* CUSTOM_OPTIONS */
 532         gettext_noop("Customized Options"),
 533         /* DEVELOPER_OPTIONS */
 534         gettext_noop("Developer Options"),
 535         /* help_config wants this array to be null-terminated */
 536         NULL
 537 };
 538
 539 /*
 540  * Displayable names for GUC variable types (enum config_type)
 541  *
 542  * Note: these strings are deliberately not localized.
 543  */
 544 const char *const config_type_names[] =
 545 {
 546          /* PGC_BOOL */ "bool",
 547          /* PGC_INT */ "integer",
 548          /* PGC_REAL */ "real",
 549          /* PGC_STRING */ "string",
 550          /* PGC_ENUM */ "enum"
 551 };
 552
 553
 554 /*
 555  * Contents of GUC tables
 556  *
 557  * See src/backend/utils/misc/README for design notes.
 558  *
 559  * TO ADD AN OPTION:
 560  *
 561  * 1. Declare a global variable of type bool, int, double, or char*
 562  *        and make use of it.
 563  *
 564  * 2. Decide at what times it's safe to set the option. See guc.h for
 565  *        details.
 566  *
 567  * 3. Decide on a name, a default value, upper and lower bounds (if
 568  *        applicable), etc.
 569  *
 570  * 4. Add a record below.
 571  *
 572  * 5. Add it to src/backend/utils/misc/postgresql.conf.sample, if
 573  *        appropriate.
 574  *
 575  * 6. Don't forget to document the option (at least in config.sgml).
 576  *
 577  * 7. If it's a new GUC_LIST option you must edit pg_dumpall.c to ensure
 578  *        it is not single quoted at dump time.
 579  */
 580
 581
 582 /******** option records follow ********/
 583
 584 static struct config_bool ConfigureNamesBool[] =
 585 {
 586         {
 587                 {"enable_seqscan", PGC_USERSET, QUERY_TUNING_METHOD,
 588                         gettext_noop("Enables the planner's use of sequential-scan plans."),
 589                         NULL
 590                 },
 591                 &enable_seqscan,
 592                 true, NULL, NULL
 593         },
 594         {
 595                 {"enable_indexscan", PGC_USERSET, QUERY_TUNING_METHOD,
 596                         gettext_noop("Enables the planner's use of index-scan plans."),
 597                         NULL
 598                 },
 599                 &enable_indexscan,
 600                 true, NULL, NULL
 601         },
 602         {
 603                 {"enable_bitmapscan", PGC_USERSET, QUERY_TUNING_METHOD,
 604                         gettext_noop("Enables the planner's use of bitmap-scan plans."),
 605                         NULL
 606                 },
 607                 &enable_bitmapscan,
 608                 true, NULL, NULL
 609         },
 610         {
 611                 {"enable_tidscan", PGC_USERSET, QUERY_TUNING_METHOD,
 612                         gettext_noop("Enables the planner's use of TID scan plans."),
 613                         NULL
 614                 },
 615                 &enable_tidscan,
 616                 true, NULL, NULL
 617         },
 618         {
 619                 {"enable_sort", PGC_USERSET, QUERY_TUNING_METHOD,
 620                         gettext_noop("Enables the planner's use of explicit sort steps."),
 621                         NULL
 622                 },
 623                 &enable_sort,
 624                 true, NULL, NULL
 625         },
 626         {
 627                 {"enable_hashagg", PGC_USERSET, QUERY_TUNING_METHOD,
 628                         gettext_noop("Enables the planner's use of hashed aggregation plans."),
 629                         NULL
 630                 },
 631                 &enable_hashagg,
 632                 true, NULL, NULL
 633         },
 634         {
 635                 {"enable_nestloop", PGC_USERSET, QUERY_TUNING_METHOD,
 636                         gettext_noop("Enables the planner's use of nested-loop join plans."),
 637                         NULL
 638                 },
 639                 &enable_nestloop,
 640                 true, NULL, NULL
 641         },
 642         {
 643                 {"enable_mergejoin", PGC_USERSET, QUERY_TUNING_METHOD,
 644                         gettext_noop("Enables the planner's use of merge join plans."),
 645                         NULL
 646                 },
 647                 &enable_mergejoin,
 648                 true, NULL, NULL
 649         },
 650         {
 651                 {"enable_hashjoin", PGC_USERSET, QUERY_TUNING_METHOD,
 652                         gettext_noop("Enables the planner's use of hash join plans."),
 653                         NULL
 654                 },
 655                 &enable_hashjoin,
 656                 true, NULL, NULL
 657         },
 658         {
 659                 {"geqo", PGC_USERSET, QUERY_TUNING_GEQO,
 660                         gettext_noop("Enables genetic query optimization."),
 661                         gettext_noop("This algorithm attempts to do planning without "
 662                                                  "exhaustive searching.")
 663                 },
 664                 &enable_geqo,
 665                 true, NULL, NULL
 666         },
 667         {
 668                 /* Not for general use --- used by SET SESSION AUTHORIZATION */
 669                 {"is_superuser", PGC_INTERNAL, UNGROUPED,
 670                         gettext_noop("Shows whether the current user is a superuser."),
 671                         NULL,
 672                         GUC_REPORT | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
 673                 },
 674                 &session_auth_is_superuser,
 675                 false, NULL, NULL
 676         },
 677         {
 678                 {"ssl", PGC_POSTMASTER, CONN_AUTH_SECURITY,
 679                         gettext_noop("Enables SSL connections."),
 680                         NULL
 681                 },
 682                 &EnableSSL,
 683                 false, assign_ssl, NULL
 684         },
 685         {
 686                 {"fsync", PGC_SIGHUP, WAL_SETTINGS,
 687                         gettext_noop("Forces synchronization of updates to disk."),
 688                         gettext_noop("The server will use the fsync() system call in several places to make "
 689                         "sure that updates are physically written to disk. This insures "
 690                                                  "that a database cluster will recover to a consistent state after "
 691                                                  "an operating system or hardware crash.")
 692                 },
 693                 &enableFsync,
 694                 true, NULL, NULL
 695         },
 696         {
 697                 {"synchronous_commit", PGC_USERSET, WAL_SETTINGS,
 698                         gettext_noop("Sets immediate fsync at commit."),
 699                         NULL
 700                 },
 701                 &XactSyncCommit,
 702                 true, NULL, NULL
 703         },
 704         {
 705                 {"zero_damaged_pages", PGC_SUSET, DEVELOPER_OPTIONS,
 706                         gettext_noop("Continues processing past damaged page headers."),
 707                         gettext_noop("Detection of a damaged page header normally causes PostgreSQL to "
 708                                 "report an error, aborting the current transaction. Setting "
 709                                                  "zero_damaged_pages to true causes the system to instead report a "
 710                                                  "warning, zero out the damaged page, and continue processing. This "
 711                                                  "behavior will destroy data, namely all the rows on the damaged page."),
 712                         GUC_NOT_IN_SAMPLE
 713                 },
 714                 &zero_damaged_pages,
 715                 false, NULL, NULL
 716         },
 717         {
 718                 {"full_page_writes", PGC_SIGHUP, WAL_SETTINGS,
 719                         gettext_noop("Writes full pages to WAL when first modified after a checkpoint."),
 720                         gettext_noop("A page write in process during an operating system crash might be "
 721                                                  "only partially written to disk.  During recovery, the row changes "
 722                           "stored in WAL are not enough to recover.  This option writes "
 723                                                  "pages when first modified after a checkpoint to WAL so full recovery "
 724                                                  "is possible.")
 725                 },
 726                 &fullPageWrites,
 727                 true, NULL, NULL
 728         },
 729         {
 730                 {"silent_mode", PGC_POSTMASTER, LOGGING_WHEN,
 731                         gettext_noop("Runs the server silently."),
 732                         gettext_noop("If this parameter is set, the server will automatically run in the "
 733                                  "background and any controlling terminals are dissociated.")
 734                 },
 735                 &SilentMode,
 736                 false, NULL, NULL
 737         },
 738         {
 739                 {"log_checkpoints", PGC_SIGHUP, LOGGING_WHAT,
 740                         gettext_noop("Logs each checkpoint."),
 741                         NULL
 742                 },
 743                 &log_checkpoints,
 744                 false, NULL, NULL
 745         },
 746         {
 747                 {"log_connections", PGC_BACKEND, LOGGING_WHAT,
 748                         gettext_noop("Logs each successful connection."),
 749                         NULL
 750                 },
 751                 &Log_connections,
 752                 false, NULL, NULL
 753         },
 754         {
 755                 {"log_disconnections", PGC_BACKEND, LOGGING_WHAT,
 756                         gettext_noop("Logs end of a session, including duration."),
 757                         NULL
 758                 },
 759                 &Log_disconnections,
 760                 false, NULL, NULL
 761         },
 762         {
 763                 {"debug_assertions", PGC_USERSET, DEVELOPER_OPTIONS,
 764                         gettext_noop("Turns on various assertion checks."),
 765                         gettext_noop("This is a debugging aid."),
 766                         GUC_NOT_IN_SAMPLE
 767                 },
 768                 &assert_enabled,
 769 #ifdef USE_ASSERT_CHECKING
 770                 true,
 771 #else
 772                 false,
 773 #endif
 774                 assign_debug_assertions, NULL
 775         },
 776         {
 777                 /* currently undocumented, so don't show in SHOW ALL */
 778                 {"exit_on_error", PGC_USERSET, UNGROUPED,
 779                         gettext_noop("No description available."),
 780                         NULL,
 781                         GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE
 782                 },
 783                 &ExitOnAnyError,
 784                 false, NULL, NULL
 785         },
 786         {
 787                 {"log_duration", PGC_SUSET, LOGGING_WHAT,
 788                         gettext_noop("Logs the duration of each completed SQL statement."),
 789                         NULL
 790                 },
 791                 &log_duration,
 792                 false, NULL, NULL
 793         },
 794         {
 795                 {"debug_print_parse", PGC_USERSET, LOGGING_WHAT,
 796                         gettext_noop("Logs each query's parse tree."),
 797                         NULL
 798                 },
 799                 &Debug_print_parse,
 800                 false, NULL, NULL
 801         },
 802         {
 803                 {"debug_print_rewritten", PGC_USERSET, LOGGING_WHAT,
 804                         gettext_noop("Logs each query's rewritten parse tree."),
 805                         NULL
 806                 },
 807                 &Debug_print_rewritten,
 808                 false, NULL, NULL
 809         },
 810         {
 811                 {"debug_print_plan", PGC_USERSET, LOGGING_WHAT,
 812                         gettext_noop("Logs each query's execution plan."),
 813                         NULL
 814                 },
 815                 &Debug_print_plan,
 816                 false, NULL, NULL
 817         },
 818         {
 819                 {"debug_pretty_print", PGC_USERSET, LOGGING_WHAT,
 820                         gettext_noop("Indents parse and plan tree displays."),
 821                         NULL
 822                 },
 823                 &Debug_pretty_print,
 824                 true, NULL, NULL
 825         },
 826         {
 827                 {"log_parser_stats", PGC_SUSET, STATS_MONITORING,
 828                         gettext_noop("Writes parser performance statistics to the server log."),
 829                         NULL
 830                 },
 831                 &log_parser_stats,
 832                 false, assign_stage_log_stats, NULL
 833         },
 834         {
 835                 {"log_planner_stats", PGC_SUSET, STATS_MONITORING,
 836                         gettext_noop("Writes planner performance statistics to the server log."),
 837                         NULL
 838                 },
 839                 &log_planner_stats,
 840                 false, assign_stage_log_stats, NULL
 841         },
 842         {
 843                 {"log_executor_stats", PGC_SUSET, STATS_MONITORING,
 844                         gettext_noop("Writes executor performance statistics to the server log."),
 845                         NULL
 846                 },
 847                 &log_executor_stats,
 848                 false, assign_stage_log_stats, NULL
 849         },
 850         {
 851                 {"log_statement_stats", PGC_SUSET, STATS_MONITORING,
 852                         gettext_noop("Writes cumulative performance statistics to the server log."),
 853                         NULL
 854                 },
 855                 &log_statement_stats,
 856                 false, assign_log_stats, NULL
 857         },
 858 #ifdef BTREE_BUILD_STATS
 859         {
 860                 {"log_btree_build_stats", PGC_SUSET, DEVELOPER_OPTIONS,
 861                         gettext_noop("No description available."),
 862                         NULL,
 863                         GUC_NOT_IN_SAMPLE
 864                 },
 865                 &log_btree_build_stats,
 866                 false, NULL, NULL
 867         },
 868 #endif
 869
 870         {
 871                 {"track_activities", PGC_SUSET, STATS_COLLECTOR,
 872                         gettext_noop("Collects information about executing commands."),
 873                         gettext_noop("Enables the collection of information on the currently "
 874                                                  "executing command of each session, along with "
 875                                                  "the time at which that command began execution.")
 876                 },
 877                 &pgstat_track_activities,
 878                 true, NULL, NULL
 879         },
 880         {
 881                 {"track_counts", PGC_SUSET, STATS_COLLECTOR,
 882                         gettext_noop("Collects statistics on database activity."),
 883                         NULL
 884                 },
 885                 &pgstat_track_counts,
 886                 true, NULL, NULL
 887         },
 888
 889         {
 890                 {"update_process_title", PGC_SUSET, STATS_COLLECTOR,
 891                         gettext_noop("Updates the process title to show the active SQL command."),
 892                         gettext_noop("Enables updating of the process title every time a new SQL command is received by the server.")
 893                 },
 894                 &update_process_title,
 895                 true, NULL, NULL
 896         },
 897
 898         {
 899                 {"autovacuum", PGC_SIGHUP, AUTOVACUUM,
 900                         gettext_noop("Starts the autovacuum subprocess."),
 901                         NULL
 902                 },
 903                 &autovacuum_start_daemon,
 904                 true, NULL, NULL
 905         },
 906
 907         {
 908                 {"trace_notify", PGC_USERSET, DEVELOPER_OPTIONS,
 909                         gettext_noop("Generates debugging output for LISTEN and NOTIFY."),
 910                         NULL,
 911                         GUC_NOT_IN_SAMPLE
 912                 },
 913                 &Trace_notify,
 914                 false, NULL, NULL
 915         },
 916
 917 #ifdef LOCK_DEBUG
 918         {
 919                 {"trace_locks", PGC_SUSET, DEVELOPER_OPTIONS,
 920                         gettext_noop("No description available."),
 921                         NULL,
 922                         GUC_NOT_IN_SAMPLE
 923                 },
 924                 &Trace_locks,
 925                 false, NULL, NULL
 926         },
 927         {
 928                 {"trace_userlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 929                         gettext_noop("No description available."),
 930                         NULL,
 931                         GUC_NOT_IN_SAMPLE
 932                 },
 933                 &Trace_userlocks,
 934                 false, NULL, NULL
 935         },
 936         {
 937                 {"trace_lwlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 938                         gettext_noop("No description available."),
 939                         NULL,
 940                         GUC_NOT_IN_SAMPLE
 941                 },
 942                 &Trace_lwlocks,
 943                 false, NULL, NULL
 944         },
 945         {
 946                 {"debug_deadlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 947                         gettext_noop("No description available."),
 948                         NULL,
 949                         GUC_NOT_IN_SAMPLE
 950                 },
 951                 &Debug_deadlocks,
 952                 false, NULL, NULL
 953         },
 954 #endif
 955
 956         {
 957                 {"log_lock_waits", PGC_SUSET, LOGGING_WHAT,
 958                         gettext_noop("Logs long lock waits."),
 959                         NULL
 960                 },
 961                 &log_lock_waits,
 962                 false, NULL, NULL
 963         },
 964
 965         {
 966                 {"log_hostname", PGC_SIGHUP, LOGGING_WHAT,
 967                         gettext_noop("Logs the host name in the connection logs."),
 968                         gettext_noop("By default, connection logs only show the IP address "
 969                                                  "of the connecting host. If you want them to show the host name you "
 970                           "can turn this on, but depending on your host name resolution "
 971                            "setup it might impose a non-negligible performance penalty.")
 972                 },
 973                 &log_hostname,
 974                 false, NULL, NULL
 975         },
 976         {
 977                 {"sql_inheritance", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
 978                         gettext_noop("Causes subtables to be included by default in various commands."),
 979                         NULL
 980                 },
 981                 &SQL_inheritance,
 982                 true, NULL, NULL
 983         },
 984         {
 985                 {"password_encryption", PGC_USERSET, CONN_AUTH_SECURITY,
 986                         gettext_noop("Encrypt passwords."),
 987                         gettext_noop("When a password is specified in CREATE USER or "
 988                            "ALTER USER without writing either ENCRYPTED or UNENCRYPTED, "
 989                                                  "this parameter determines whether the password is to be encrypted.")
 990                 },
 991                 &Password_encryption,
 992                 true, NULL, NULL
 993         },
 994         {
 995                 {"transform_null_equals", PGC_USERSET, COMPAT_OPTIONS_CLIENT,
 996                         gettext_noop("Treats \"expr=NULL\" as \"expr IS NULL\"."),
 997                         gettext_noop("When turned on, expressions of the form expr = NULL "
 998                            "(or NULL = expr) are treated as expr IS NULL, that is, they "
 999                                 "return true if expr evaluates to the null value, and false "
1000                            "otherwise. The correct behavior of expr = NULL is to always "
1001                                                  "return null (unknown).")
1002                 },
1003                 &Transform_null_equals,
1004                 false, NULL, NULL
1005         },
1006         {
1007                 {"db_user_namespace", PGC_SIGHUP, CONN_AUTH_SECURITY,
1008                         gettext_noop("Enables per-database user names."),
1009                         NULL
1010                 },
1011                 &Db_user_namespace,
1012                 false, NULL, NULL
1013         },
1014         {
1015                 /* only here for backwards compatibility */
1016                 {"autocommit", PGC_USERSET, CLIENT_CONN_STATEMENT,
1017                         gettext_noop("This parameter doesn't do anything."),
1018                         gettext_noop("It's just here so that we won't choke on SET AUTOCOMMIT TO ON from 7.3-vintage clients."),
1019                         GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE
1020                 },
1021                 &phony_autocommit,
1022                 true, assign_phony_autocommit, NULL
1023         },
1024         {
1025                 {"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
1026                         gettext_noop("Sets the default read-only status of new transactions."),
1027                         NULL
1028                 },
1029                 &DefaultXactReadOnly,
1030                 false, NULL, NULL
1031         },
1032         {
1033                 {"transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
1034                         gettext_noop("Sets the current transaction's read-only status."),
1035                         NULL,
1036                         GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1037                 },
1038                 &XactReadOnly,
1039                 false, assign_transaction_read_only, NULL
1040         },
1041         {
1042                 {"add_missing_from", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1043                         gettext_noop("Automatically adds missing table references to FROM clauses."),
1044                         NULL
1045                 },
1046                 &add_missing_from,
1047                 false, NULL, NULL
1048         },
1049         {
1050                 {"check_function_bodies", PGC_USERSET, CLIENT_CONN_STATEMENT,
1051                         gettext_noop("Check function bodies during CREATE FUNCTION."),
1052                         NULL
1053                 },
1054                 &check_function_bodies,
1055                 true, NULL, NULL
1056         },
1057         {
1058                 {"array_nulls", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1059                         gettext_noop("Enable input of NULL elements in arrays."),
1060                         gettext_noop("When turned on, unquoted NULL in an array input "
1061                                                  "value means a null value; "
1062                                                  "otherwise it is taken literally.")
1063                 },
1064                 &Array_nulls,
1065                 true, NULL, NULL
1066         },
1067         {
1068                 {"default_with_oids", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1069                         gettext_noop("Create new tables with OIDs by default."),
1070                         NULL
1071                 },
1072                 &default_with_oids,
1073                 false, NULL, NULL
1074         },
1075         {
1076                 {"logging_collector", PGC_POSTMASTER, LOGGING_WHERE,
1077                         gettext_noop("Start a subprocess to capture stderr output and/or csvlogs into log files."),
1078                         NULL
1079                 },
1080                 &Logging_collector,
1081                 false, NULL, NULL
1082         },
1083         {
1084                 {"log_truncate_on_rotation", PGC_SIGHUP, LOGGING_WHERE,
1085                         gettext_noop("Truncate existing log files of same name during log rotation."),
1086                         NULL
1087                 },
1088                 &Log_truncate_on_rotation,
1089                 false, NULL, NULL
1090         },
1091
1092 #ifdef TRACE_SORT
1093         {
1094                 {"trace_sort", PGC_USERSET, DEVELOPER_OPTIONS,
1095                         gettext_noop("Emit information about resource usage in sorting."),
1096                         NULL,
1097                         GUC_NOT_IN_SAMPLE
1098                 },
1099                 &trace_sort,
1100                 false, NULL, NULL
1101         },
1102 #endif
1103
1104 #ifdef TRACE_SYNCSCAN
1105         /* this is undocumented because not exposed in a standard build */
1106         {
1107                 {"trace_syncscan", PGC_USERSET, DEVELOPER_OPTIONS,
1108                         gettext_noop("Generate debugging output for synchronized scanning."),
1109                         NULL,
1110                         GUC_NOT_IN_SAMPLE
1111                 },
1112                 &trace_syncscan,
1113                 false, NULL, NULL
1114         },
1115 #endif
1116
1117 #ifdef DEBUG_BOUNDED_SORT
1118         /* this is undocumented because not exposed in a standard build */
1119         {
1120                 {
1121                         "optimize_bounded_sort", PGC_USERSET, QUERY_TUNING_METHOD,
1122                         gettext_noop("Enable bounded sorting using heap sort."),
1123                         NULL,
1124                         GUC_NOT_IN_SAMPLE
1125                 },
1126                 &optimize_bounded_sort,
1127                 true, NULL, NULL
1128         },
1129 #endif
1130
1131 #ifdef WAL_DEBUG
1132         {
1133                 {"wal_debug", PGC_SUSET, DEVELOPER_OPTIONS,
1134                         gettext_noop("Emit WAL-related debugging output."),
1135                         NULL,
1136                         GUC_NOT_IN_SAMPLE
1137                 },
1138                 &XLOG_DEBUG,
1139                 false, NULL, NULL
1140         },
1141 #endif
1142
1143         {
1144                 {"integer_datetimes", PGC_INTERNAL, PRESET_OPTIONS,
1145                         gettext_noop("Datetimes are integer based."),
1146                         NULL,
1147                         GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1148                 },
1149                 &integer_datetimes,
1150 #ifdef HAVE_INT64_TIMESTAMP
1151                 true, NULL, NULL
1152 #else
1153                 false, NULL, NULL
1154 #endif
1155         },
1156
1157         {
1158                 {"krb_caseins_users", PGC_SIGHUP, CONN_AUTH_SECURITY,
1159                         gettext_noop("Sets whether Kerberos and GSSAPI user names should be treated as case-insensitive."),
1160                         NULL
1161                 },
1162                 &pg_krb_caseins_users,
1163                 false, NULL, NULL
1164         },
1165
1166         {
1167                 {"escape_string_warning", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1168                         gettext_noop("Warn about backslash escapes in ordinary string literals."),
1169                         NULL
1170                 },
1171                 &escape_string_warning,
1172                 true, NULL, NULL
1173         },
1174
1175         {
1176                 {"standard_conforming_strings", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1177                         gettext_noop("Causes '...' strings to treat backslashes literally."),
1178                         NULL,
1179                         GUC_REPORT
1180                 },
1181                 &standard_conforming_strings,
1182                 false, NULL, NULL
1183         },
1184
1185         {
1186                 {"synchronize_seqscans", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1187                         gettext_noop("Enable synchronized sequential scans."),
1188                         NULL
1189                 },
1190                 &synchronize_seqscans,
1191                 true, NULL, NULL
1192         },
1193
1194         {
1195                 {"archive_mode", PGC_POSTMASTER, WAL_SETTINGS,
1196                         gettext_noop("Allows archiving of WAL files using archive_command."),
1197                         NULL
1198                 },
1199                 &XLogArchiveMode,
1200                 false, NULL, NULL
1201         },
1202
1203         {
1204                 {"allow_system_table_mods", PGC_POSTMASTER, DEVELOPER_OPTIONS,
1205                         gettext_noop("Allows modifications of the structure of system tables."),
1206                         NULL,
1207                         GUC_NOT_IN_SAMPLE
1208                 },
1209                 &allowSystemTableMods,
1210                 false, NULL, NULL
1211         },
1212
1213         {
1214                 {"ignore_system_indexes", PGC_BACKEND, DEVELOPER_OPTIONS,
1215                         gettext_noop("Disables reading from system indexes."),
1216                         gettext_noop("It does not prevent updating the indexes, so it is safe "
1217                                                  "to use.  The worst consequence is slowness."),
1218                         GUC_NOT_IN_SAMPLE
1219                 },
1220                 &IgnoreSystemIndexes,
1221                 false, NULL, NULL
1222         },
1223
1224         /* End-of-list marker */
1225         {
1226                 {NULL, 0, 0, NULL, NULL}, NULL, false, NULL, NULL
1227         }
1228 };
1229
1230
1231 static struct config_int ConfigureNamesInt[] =
1232 {
1233         {
1234                 {"archive_timeout", PGC_SIGHUP, WAL_SETTINGS,
1235                         gettext_noop("Forces a switch to the next xlog file if a "
1236                                                  "new file has not been started within N seconds."),
1237                         NULL,
1238                         GUC_UNIT_S
1239                 },
1240                 &XLogArchiveTimeout,
1241                 0, 0, INT_MAX, NULL, NULL
1242         },
1243         {
1244                 {"post_auth_delay", PGC_BACKEND, DEVELOPER_OPTIONS,
1245                         gettext_noop("Waits N seconds on connection startup after authentication."),
1246                         gettext_noop("This allows attaching a debugger to the process."),
1247                         GUC_NOT_IN_SAMPLE | GUC_UNIT_S
1248                 },
1249                 &PostAuthDelay,
1250                 0, 0, INT_MAX, NULL, NULL
1251         },
1252         {
1253                 {"default_statistics_target", PGC_USERSET, QUERY_TUNING_OTHER,
1254                         gettext_noop("Sets the default statistics target."),
1255                         gettext_noop("This applies to table columns that have not had a "
1256                                 "column-specific target set via ALTER TABLE SET STATISTICS.")
1257                 },
1258                 &default_statistics_target,
1259                 100, 1, 10000, NULL, NULL
1260         },
1261         {
1262                 {"from_collapse_limit", PGC_USERSET, QUERY_TUNING_OTHER,
1263                         gettext_noop("Sets the FROM-list size beyond which subqueries "
1264                                                  "are not collapsed."),
1265                         gettext_noop("The planner will merge subqueries into upper "
1266                                 "queries if the resulting FROM list would have no more than "
1267                                                  "this many items.")
1268                 },
1269                 &from_collapse_limit,
1270                 8, 1, INT_MAX, NULL, NULL
1271         },
1272         {
1273                 {"join_collapse_limit", PGC_USERSET, QUERY_TUNING_OTHER,
1274                         gettext_noop("Sets the FROM-list size beyond which JOIN "
1275                                                  "constructs are not flattened."),
1276                         gettext_noop("The planner will flatten explicit JOIN "
1277                                                  "constructs into lists of FROM items whenever a "
1278                                                  "list of no more than this many items would result.")
1279                 },
1280                 &join_collapse_limit,
1281                 8, 1, INT_MAX, NULL, NULL
1282         },
1283         {
1284                 {"geqo_threshold", PGC_USERSET, QUERY_TUNING_GEQO,
1285                         gettext_noop("Sets the threshold of FROM items beyond which GEQO is used."),
1286                         NULL
1287                 },
1288                 &geqo_threshold,
1289                 12, 2, INT_MAX, NULL, NULL
1290         },
1291         {
1292                 {"geqo_effort", PGC_USERSET, QUERY_TUNING_GEQO,
1293                         gettext_noop("GEQO: effort is used to set the default for other GEQO parameters."),
1294                         NULL
1295                 },
1296                 &Geqo_effort,
1297                 DEFAULT_GEQO_EFFORT, MIN_GEQO_EFFORT, MAX_GEQO_EFFORT, NULL, NULL
1298         },
1299         {
1300                 {"geqo_pool_size", PGC_USERSET, QUERY_TUNING_GEQO,
1301                         gettext_noop("GEQO: number of individuals in the population."),
1302                         gettext_noop("Zero selects a suitable default value.")
1303                 },
1304                 &Geqo_pool_size,
1305                 0, 0, INT_MAX, NULL, NULL
1306         },
1307         {
1308                 {"geqo_generations", PGC_USERSET, QUERY_TUNING_GEQO,
1309                         gettext_noop("GEQO: number of iterations of the algorithm."),
1310                         gettext_noop("Zero selects a suitable default value.")
1311                 },
1312                 &Geqo_generations,
1313                 0, 0, INT_MAX, NULL, NULL
1314         },
1315
1316         {
1317                 /* This is PGC_SIGHUP so all backends have the same value. */
1318                 {"deadlock_timeout", PGC_SIGHUP, LOCK_MANAGEMENT,
1319                         gettext_noop("Sets the time to wait on a lock before checking for deadlock."),
1320                         NULL,
1321                         GUC_UNIT_MS
1322                 },
1323                 &DeadlockTimeout,
1324                 1000, 1, INT_MAX / 1000, NULL, NULL
1325         },
1326
1327         /*
1328          * Note: MaxBackends is limited to INT_MAX/4 because some places compute
1329          * 4*MaxBackends without any overflow check.  This check is made in
1330          * assign_maxconnections, since MaxBackends is computed as MaxConnections
1331          * plus autovacuum_max_workers.
1332          *
1333          * Likewise we have to limit NBuffers to INT_MAX/2.
1334          */
1335         {
1336                 {"max_connections", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1337                         gettext_noop("Sets the maximum number of concurrent connections."),
1338                         NULL
1339                 },
1340                 &MaxConnections,
1341                 100, 1, INT_MAX / 4, assign_maxconnections, NULL
1342         },
1343
1344         {
1345                 {"superuser_reserved_connections", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1346                         gettext_noop("Sets the number of connection slots reserved for superusers."),
1347                         NULL
1348                 },
1349                 &ReservedBackends,
1350                 3, 0, INT_MAX / 4, NULL, NULL
1351         },
1352
1353         {
1354                 {"shared_buffers", PGC_POSTMASTER, RESOURCES_MEM,
1355                         gettext_noop("Sets the number of shared memory buffers used by the server."),
1356                         NULL,
1357                         GUC_UNIT_BLOCKS
1358                 },
1359                 &NBuffers,
1360                 1024, 16, INT_MAX / 2, NULL, NULL
1361         },
1362
1363         {
1364                 {"temp_buffers", PGC_USERSET, RESOURCES_MEM,
1365                         gettext_noop("Sets the maximum number of temporary buffers used by each session."),
1366                         NULL,
1367                         GUC_UNIT_BLOCKS
1368                 },
1369                 &num_temp_buffers,
1370                 1024, 100, INT_MAX / 2, NULL, show_num_temp_buffers
1371         },
1372
1373         {
1374                 {"port", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1375                         gettext_noop("Sets the TCP port the server listens on."),
1376                         NULL
1377                 },
1378                 &PostPortNumber,
1379                 DEF_PGPORT, 1, 65535, NULL, NULL
1380         },
1381
1382         {
1383                 {"unix_socket_permissions", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1384                         gettext_noop("Sets the access permissions of the Unix-domain socket."),
1385                         gettext_noop("Unix-domain sockets use the usual Unix file system "
1386                                                  "permission set. The parameter value is expected to be a numeric mode "
1387                                                  "specification in the form accepted by the chmod and umask system "
1388                                                  "calls. (To use the customary octal format the number must start with "
1389                                                  "a 0 (zero).)")
1390                 },
1391                 &Unix_socket_permissions,
1392                 0777, 0000, 0777, NULL, NULL
1393         },
1394
1395         {
1396                 {"work_mem", PGC_USERSET, RESOURCES_MEM,
1397                         gettext_noop("Sets the maximum memory to be used for query workspaces."),
1398                         gettext_noop("This much memory can be used by each internal "
1399                                                  "sort operation and hash table before switching to "
1400                                                  "temporary disk files."),
1401                         GUC_UNIT_KB
1402                 },
1403                 &work_mem,
1404                 1024, 64, MAX_KILOBYTES, NULL, NULL
1405         },
1406
1407         {
1408                 {"maintenance_work_mem", PGC_USERSET, RESOURCES_MEM,
1409                         gettext_noop("Sets the maximum memory to be used for maintenance operations."),
1410                         gettext_noop("This includes operations such as VACUUM and CREATE INDEX."),
1411                         GUC_UNIT_KB
1412                 },
1413                 &maintenance_work_mem,
1414                 16384, 1024, MAX_KILOBYTES, NULL, NULL
1415         },
1416
1417         {
1418                 {"max_stack_depth", PGC_SUSET, RESOURCES_MEM,
1419                         gettext_noop("Sets the maximum stack depth, in kilobytes."),
1420                         NULL,
1421                         GUC_UNIT_KB
1422                 },
1423                 &max_stack_depth,
1424                 100, 100, MAX_KILOBYTES, assign_max_stack_depth, NULL
1425         },
1426
1427         {
1428                 {"vacuum_cost_page_hit", PGC_USERSET, RESOURCES,
1429                         gettext_noop("Vacuum cost for a page found in the buffer cache."),
1430                         NULL
1431                 },
1432                 &VacuumCostPageHit,
1433                 1, 0, 10000, NULL, NULL
1434         },
1435
1436         {
1437                 {"vacuum_cost_page_miss", PGC_USERSET, RESOURCES,
1438                         gettext_noop("Vacuum cost for a page not found in the buffer cache."),
1439                         NULL
1440                 },
1441                 &VacuumCostPageMiss,
1442                 10, 0, 10000, NULL, NULL
1443         },
1444
1445         {
1446                 {"vacuum_cost_page_dirty", PGC_USERSET, RESOURCES,
1447                         gettext_noop("Vacuum cost for a page dirtied by vacuum."),
1448                         NULL
1449                 },
1450                 &VacuumCostPageDirty,
1451                 20, 0, 10000, NULL, NULL
1452         },
1453
1454         {
1455                 {"vacuum_cost_limit", PGC_USERSET, RESOURCES,
1456                         gettext_noop("Vacuum cost amount available before napping."),
1457                         NULL
1458                 },
1459                 &VacuumCostLimit,
1460                 200, 1, 10000, NULL, NULL
1461         },
1462
1463         {
1464                 {"vacuum_cost_delay", PGC_USERSET, RESOURCES,
1465                         gettext_noop("Vacuum cost delay in milliseconds."),
1466                         NULL,
1467                         GUC_UNIT_MS
1468                 },
1469                 &VacuumCostDelay,
1470                 0, 0, 100, NULL, NULL
1471         },
1472
1473         {
1474                 {"autovacuum_vacuum_cost_delay", PGC_SIGHUP, AUTOVACUUM,
1475                         gettext_noop("Vacuum cost delay in milliseconds, for autovacuum."),
1476                         NULL,
1477                         GUC_UNIT_MS
1478                 },
1479                 &autovacuum_vac_cost_delay,
1480                 20, -1, 100, NULL, NULL
1481         },
1482
1483         {
1484                 {"autovacuum_vacuum_cost_limit", PGC_SIGHUP, AUTOVACUUM,
1485                         gettext_noop("Vacuum cost amount available before napping, for autovacuum."),
1486                         NULL
1487                 },
1488                 &autovacuum_vac_cost_limit,
1489                 -1, -1, 10000, NULL, NULL
1490         },
1491
1492         {
1493                 {"max_files_per_process", PGC_POSTMASTER, RESOURCES_KERNEL,
1494                         gettext_noop("Sets the maximum number of simultaneously open files for each server process."),
1495                         NULL
1496                 },
1497                 &max_files_per_process,
1498                 1000, 25, INT_MAX, NULL, NULL
1499         },
1500
1501         {
1502                 {"max_prepared_transactions", PGC_POSTMASTER, RESOURCES,
1503                         gettext_noop("Sets the maximum number of simultaneously prepared transactions."),
1504                         NULL
1505                 },
1506                 &max_prepared_xacts,
1507                 0, 0, INT_MAX / 4, NULL, NULL
1508         },
1509
1510 #ifdef LOCK_DEBUG
1511         {
1512                 {"trace_lock_oidmin", PGC_SUSET, DEVELOPER_OPTIONS,
1513                         gettext_noop("No description available."),
1514                         NULL,
1515                         GUC_NOT_IN_SAMPLE
1516                 },
1517                 &Trace_lock_oidmin,
1518                 FirstNormalObjectId, 0, INT_MAX, NULL, NULL
1519         },
1520         {
1521                 {"trace_lock_table", PGC_SUSET, DEVELOPER_OPTIONS,
1522                         gettext_noop("No description available."),
1523                         NULL,
1524                         GUC_NOT_IN_SAMPLE
1525                 },
1526                 &Trace_lock_table,
1527                 0, 0, INT_MAX, NULL, NULL
1528         },
1529 #endif
1530
1531         {
1532                 {"statement_timeout", PGC_USERSET, CLIENT_CONN_STATEMENT,
1533                         gettext_noop("Sets the maximum allowed duration of any statement."),
1534                         gettext_noop("A value of 0 turns off the timeout."),
1535                         GUC_UNIT_MS
1536                 },
1537                 &StatementTimeout,
1538                 0, 0, INT_MAX, NULL, NULL
1539         },
1540
1541         {
1542                 {"vacuum_freeze_min_age", PGC_USERSET, CLIENT_CONN_STATEMENT,
1543                         gettext_noop("Minimum age at which VACUUM should freeze a table row."),
1544                         NULL
1545                 },
1546                 &vacuum_freeze_min_age,
1547                 50000000, 0, 1000000000, NULL, NULL
1548         },
1549
1550         {
1551                 {"vacuum_freeze_table_age", PGC_USERSET, CLIENT_CONN_STATEMENT,
1552                         gettext_noop("Age at which VACUUM should scan whole table to freeze tuples."),
1553                         NULL
1554                 },
1555                 &vacuum_freeze_table_age,
1556                 150000000, 0, 2000000000, NULL, NULL
1557         },
1558
1559         {
1560                 {"max_locks_per_transaction", PGC_POSTMASTER, LOCK_MANAGEMENT,
1561                         gettext_noop("Sets the maximum number of locks per transaction."),
1562                         gettext_noop("The shared lock table is sized on the assumption that "
1563                           "at most max_locks_per_transaction * max_connections distinct "
1564                                                  "objects will need to be locked at any one time.")
1565                 },
1566                 &max_locks_per_xact,
1567                 64, 10, INT_MAX, NULL, NULL
1568         },
1569
1570         {
1571                 {"authentication_timeout", PGC_SIGHUP, CONN_AUTH_SECURITY,
1572                         gettext_noop("Sets the maximum allowed time to complete client authentication."),
1573                         NULL,
1574                         GUC_UNIT_S
1575                 },
1576                 &AuthenticationTimeout,
1577                 60, 1, 600, NULL, NULL
1578         },
1579
1580         {
1581                 /* Not for general use */
1582                 {"pre_auth_delay", PGC_SIGHUP, DEVELOPER_OPTIONS,
1583                         gettext_noop("Waits N seconds on connection startup before authentication."),
1584                         gettext_noop("This allows attaching a debugger to the process."),
1585                         GUC_NOT_IN_SAMPLE | GUC_UNIT_S
1586                 },
1587                 &PreAuthDelay,
1588                 0, 0, 60, NULL, NULL
1589         },
1590
1591         {
1592                 {"checkpoint_segments", PGC_SIGHUP, WAL_CHECKPOINTS,
1593                         gettext_noop("Sets the maximum distance in log segments between automatic WAL checkpoints."),
1594                         NULL
1595                 },
1596                 &CheckPointSegments,
1597                 3, 1, INT_MAX, NULL, NULL
1598         },
1599
1600         {
1601                 {"checkpoint_timeout", PGC_SIGHUP, WAL_CHECKPOINTS,
1602                         gettext_noop("Sets the maximum time between automatic WAL checkpoints."),
1603                         NULL,
1604                         GUC_UNIT_S
1605                 },
1606                 &CheckPointTimeout,
1607                 300, 30, 3600, NULL, NULL
1608         },
1609
1610         {
1611                 {"checkpoint_warning", PGC_SIGHUP, WAL_CHECKPOINTS,
1612                         gettext_noop("Enables warnings if checkpoint segments are filled more "
1613                                                  "frequently than this."),
1614                         gettext_noop("Write a message to the server log if checkpoints "
1615                         "caused by the filling of checkpoint segment files happens more "
1616                                                  "frequently than this number of seconds. Zero turns off the warning."),
1617                         GUC_UNIT_S
1618                 },
1619                 &CheckPointWarning,
1620                 30, 0, INT_MAX, NULL, NULL
1621         },
1622
1623         {
1624                 {"wal_buffers", PGC_POSTMASTER, WAL_SETTINGS,
1625                         gettext_noop("Sets the number of disk-page buffers in shared memory for WAL."),
1626                         NULL,
1627                         GUC_UNIT_XBLOCKS
1628                 },
1629                 &XLOGbuffers,
1630                 8, 4, INT_MAX, NULL, NULL
1631         },
1632
1633         {
1634                 {"wal_writer_delay", PGC_SIGHUP, WAL_SETTINGS,
1635                         gettext_noop("WAL writer sleep time between WAL flushes."),
1636                         NULL,
1637                         GUC_UNIT_MS
1638                 },
1639                 &WalWriterDelay,
1640                 200, 1, 10000, NULL, NULL
1641         },
1642
1643         {
1644                 {"commit_delay", PGC_USERSET, WAL_SETTINGS,
1645                         gettext_noop("Sets the delay in microseconds between transaction commit and "
1646                                                  "flushing WAL to disk."),
1647                         NULL
1648                 },
1649                 &CommitDelay,
1650                 0, 0, 100000, NULL, NULL
1651         },
1652
1653         {
1654                 {"commit_siblings", PGC_USERSET, WAL_SETTINGS,
1655                         gettext_noop("Sets the minimum concurrent open transactions before performing "
1656                                                  "commit_delay."),
1657                         NULL
1658                 },
1659                 &CommitSiblings,
1660                 5, 1, 1000, NULL, NULL
1661         },
1662
1663         {
1664                 {"extra_float_digits", PGC_USERSET, CLIENT_CONN_LOCALE,
1665                         gettext_noop("Sets the number of digits displayed for floating-point values."),
1666                         gettext_noop("This affects real, double precision, and geometric data types. "
1667                          "The parameter value is added to the standard number of digits "
1668                                                  "(FLT_DIG or DBL_DIG as appropriate).")
1669                 },
1670                 &extra_float_digits,
1671                 0, -15, 2, NULL, NULL
1672         },
1673
1674         {
1675                 {"log_min_duration_statement", PGC_SUSET, LOGGING_WHEN,
1676                         gettext_noop("Sets the minimum execution time above which "
1677                                                  "statements will be logged."),
1678                         gettext_noop("Zero prints all queries. -1 turns this feature off."),
1679                         GUC_UNIT_MS
1680                 },
1681                 &log_min_duration_statement,
1682                 -1, -1, INT_MAX / 1000, NULL, NULL
1683         },
1684
1685         {
1686                 {"log_autovacuum_min_duration", PGC_SIGHUP, LOGGING_WHAT,
1687                         gettext_noop("Sets the minimum execution time above which "
1688                                                  "autovacuum actions will be logged."),
1689                         gettext_noop("Zero prints all actions. -1 turns autovacuum logging off."),
1690                         GUC_UNIT_MS
1691                 },
1692                 &Log_autovacuum_min_duration,
1693                 -1, -1, INT_MAX / 1000, NULL, NULL
1694         },
1695
1696         {
1697                 {"bgwriter_delay", PGC_SIGHUP, RESOURCES,
1698                         gettext_noop("Background writer sleep time between rounds."),
1699                         NULL,
1700                         GUC_UNIT_MS
1701                 },
1702                 &BgWriterDelay,
1703                 200, 10, 10000, NULL, NULL
1704         },
1705
1706         {
1707                 {"bgwriter_lru_maxpages", PGC_SIGHUP, RESOURCES,
1708                         gettext_noop("Background writer maximum number of LRU pages to flush per round."),
1709                         NULL
1710                 },
1711                 &bgwriter_lru_maxpages,
1712                 100, 0, 1000, NULL, NULL
1713         },
1714
1715         {
1716                 {"effective_io_concurrency",
1717 #ifdef USE_PREFETCH
1718                         PGC_USERSET,
1719 #else
1720                         PGC_INTERNAL,
1721 #endif
1722                         RESOURCES,
1723                         gettext_noop("Number of simultaneous requests that can be handled efficiently by the disk subsystem."),
1724                         gettext_noop("For RAID arrays, this should be approximately the number of drive spindles in the array.")
1725                 },
1726                 &effective_io_concurrency,
1727 #ifdef USE_PREFETCH
1728                 1, 0, 1000,
1729 #else
1730                 0, 0, 0,
1731 #endif
1732                 assign_effective_io_concurrency, NULL
1733         },
1734
1735         {
1736                 {"log_rotation_age", PGC_SIGHUP, LOGGING_WHERE,
1737                         gettext_noop("Automatic log file rotation will occur after N minutes."),
1738                         NULL,
1739                         GUC_UNIT_MIN
1740                 },
1741                 &Log_RotationAge,
1742                 HOURS_PER_DAY * MINS_PER_HOUR, 0, INT_MAX / MINS_PER_HOUR, NULL, NULL
1743         },
1744
1745         {
1746                 {"log_rotation_size", PGC_SIGHUP, LOGGING_WHERE,
1747                         gettext_noop("Automatic log file rotation will occur after N kilobytes."),
1748                         NULL,
1749                         GUC_UNIT_KB
1750                 },
1751                 &Log_RotationSize,
1752                 10 * 1024, 0, INT_MAX / 1024, NULL, NULL
1753         },
1754
1755         {
1756                 {"max_function_args", PGC_INTERNAL, PRESET_OPTIONS,
1757                         gettext_noop("Shows the maximum number of function arguments."),
1758                         NULL,
1759                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1760                 },
1761                 &max_function_args,
1762                 FUNC_MAX_ARGS, FUNC_MAX_ARGS, FUNC_MAX_ARGS, NULL, NULL
1763         },
1764
1765         {
1766                 {"max_index_keys", PGC_INTERNAL, PRESET_OPTIONS,
1767                         gettext_noop("Shows the maximum number of index keys."),
1768                         NULL,
1769                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1770                 },
1771                 &max_index_keys,
1772                 INDEX_MAX_KEYS, INDEX_MAX_KEYS, INDEX_MAX_KEYS, NULL, NULL
1773         },
1774
1775         {
1776                 {"max_identifier_length", PGC_INTERNAL, PRESET_OPTIONS,
1777                         gettext_noop("Shows the maximum identifier length."),
1778                         NULL,
1779                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1780                 },
1781                 &max_identifier_length,
1782                 NAMEDATALEN - 1, NAMEDATALEN - 1, NAMEDATALEN - 1, NULL, NULL
1783         },
1784
1785         {
1786                 {"block_size", PGC_INTERNAL, PRESET_OPTIONS,
1787                         gettext_noop("Shows the size of a disk block."),
1788                         NULL,
1789                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1790                 },
1791                 &block_size,
1792                 BLCKSZ, BLCKSZ, BLCKSZ, NULL, NULL
1793         },
1794
1795         {
1796                 {"segment_size", PGC_INTERNAL, PRESET_OPTIONS,
1797                         gettext_noop("Shows the number of pages per disk file."),
1798                         NULL,
1799                         GUC_UNIT_BLOCKS | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1800                 },
1801                 &segment_size,
1802                 RELSEG_SIZE, RELSEG_SIZE, RELSEG_SIZE, NULL, NULL
1803         },
1804
1805         {
1806                 {"wal_block_size", PGC_INTERNAL, PRESET_OPTIONS,
1807                         gettext_noop("Shows the block size in the write ahead log."),
1808                         NULL,
1809                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1810                 },
1811                 &wal_block_size,
1812                 XLOG_BLCKSZ, XLOG_BLCKSZ, XLOG_BLCKSZ, NULL, NULL
1813         },
1814
1815         {
1816                 {"wal_segment_size", PGC_INTERNAL, PRESET_OPTIONS,
1817                         gettext_noop("Shows the number of pages per write ahead log segment."),
1818                         NULL,
1819                         GUC_UNIT_XBLOCKS | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1820                 },
1821                 &wal_segment_size,
1822                 (XLOG_SEG_SIZE / XLOG_BLCKSZ),
1823                 (XLOG_SEG_SIZE / XLOG_BLCKSZ),
1824                 (XLOG_SEG_SIZE / XLOG_BLCKSZ),
1825                 NULL, NULL
1826         },
1827
1828         {
1829                 {"autovacuum_naptime", PGC_SIGHUP, AUTOVACUUM,
1830                         gettext_noop("Time to sleep between autovacuum runs."),
1831                         NULL,
1832                         GUC_UNIT_S
1833                 },
1834                 &autovacuum_naptime,
1835                 60, 1, INT_MAX / 1000, NULL, NULL
1836         },
1837         {
1838                 {"autovacuum_vacuum_threshold", PGC_SIGHUP, AUTOVACUUM,
1839                         gettext_noop("Minimum number of tuple updates or deletes prior to vacuum."),
1840                         NULL
1841                 },
1842                 &autovacuum_vac_thresh,
1843                 50, 0, INT_MAX, NULL, NULL
1844         },
1845         {
1846                 {"autovacuum_analyze_threshold", PGC_SIGHUP, AUTOVACUUM,
1847                         gettext_noop("Minimum number of tuple inserts, updates or deletes prior to analyze."),
1848                         NULL
1849                 },
1850                 &autovacuum_anl_thresh,
1851                 50, 0, INT_MAX, NULL, NULL
1852         },
1853         {
1854                 /* see varsup.c for why this is PGC_POSTMASTER not PGC_SIGHUP */
1855                 {"autovacuum_freeze_max_age", PGC_POSTMASTER, AUTOVACUUM,
1856                         gettext_noop("Age at which to autovacuum a table to prevent transaction ID wraparound."),
1857                         NULL
1858                 },
1859                 &autovacuum_freeze_max_age,
1860                 200000000, 100000000, 2000000000, NULL, NULL
1861         },
1862         {
1863                 /* see max_connections */
1864                 {"autovacuum_max_workers", PGC_POSTMASTER, AUTOVACUUM,
1865                         gettext_noop("Sets the maximum number of simultaneously running autovacuum worker processes."),
1866                         NULL
1867                 },
1868                 &autovacuum_max_workers,
1869                 3, 1, INT_MAX / 4, assign_autovacuum_max_workers, NULL
1870         },
1871
1872         {
1873                 {"tcp_keepalives_idle", PGC_USERSET, CLIENT_CONN_OTHER,
1874                         gettext_noop("Time between issuing TCP keepalives."),
1875                         gettext_noop("A value of 0 uses the system default."),
1876                         GUC_UNIT_S
1877                 },
1878                 &tcp_keepalives_idle,
1879                 0, 0, INT_MAX, assign_tcp_keepalives_idle, show_tcp_keepalives_idle
1880         },
1881
1882         {
1883                 {"tcp_keepalives_interval", PGC_USERSET, CLIENT_CONN_OTHER,
1884                         gettext_noop("Time between TCP keepalive retransmits."),
1885                         gettext_noop("A value of 0 uses the system default."),
1886                         GUC_UNIT_S
1887                 },
1888                 &tcp_keepalives_interval,
1889                 0, 0, INT_MAX, assign_tcp_keepalives_interval, show_tcp_keepalives_interval
1890         },
1891
1892         {
1893                 {"tcp_keepalives_count", PGC_USERSET, CLIENT_CONN_OTHER,
1894                         gettext_noop("Maximum number of TCP keepalive retransmits."),
1895                         gettext_noop("This controls the number of consecutive keepalive retransmits that can be "
1896                                                  "lost before a connection is considered dead. A value of 0 uses the "
1897                                                  "system default."),
1898                 },
1899                 &tcp_keepalives_count,
1900                 0, 0, INT_MAX, assign_tcp_keepalives_count, show_tcp_keepalives_count
1901         },
1902
1903         {
1904                 {"gin_fuzzy_search_limit", PGC_USERSET, CLIENT_CONN_OTHER,
1905                         gettext_noop("Sets the maximum allowed result for exact search by GIN."),
1906                         NULL,
1907                         0
1908                 },
1909                 &GinFuzzySearchLimit,
1910                 0, 0, INT_MAX, NULL, NULL
1911         },
1912
1913         {
1914                 {"effective_cache_size", PGC_USERSET, QUERY_TUNING_COST,
1915                         gettext_noop("Sets the planner's assumption about the size of the disk cache."),
1916                         gettext_noop("That is, the portion of the kernel's disk cache that "
1917                                                  "will be used for PostgreSQL data files. This is measured in disk "
1918                                                  "pages, which are normally 8 kB each."),
1919                         GUC_UNIT_BLOCKS,
1920                 },
1921                 &effective_cache_size,
1922                 DEFAULT_EFFECTIVE_CACHE_SIZE, 1, INT_MAX, NULL, NULL
1923         },
1924
1925         {
1926                 /* Can't be set in postgresql.conf */
1927                 {"server_version_num", PGC_INTERNAL, PRESET_OPTIONS,
1928                         gettext_noop("Shows the server version as an integer."),
1929                         NULL,
1930                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1931                 },
1932                 &server_version_num,
1933                 PG_VERSION_NUM, PG_VERSION_NUM, PG_VERSION_NUM, NULL, NULL
1934         },
1935
1936         {
1937                 {"log_temp_files", PGC_SUSET, LOGGING_WHAT,
1938                         gettext_noop("Log the use of temporary files larger than this number of kilobytes."),
1939                         gettext_noop("Zero logs all files. The default is -1 (turning this feature off)."),
1940                         GUC_UNIT_KB
1941                 },
1942                 &log_temp_files,
1943                 -1, -1, INT_MAX, NULL, NULL
1944         },
1945
1946         {
1947                 {"track_activity_query_size", PGC_POSTMASTER, RESOURCES_MEM,
1948                         gettext_noop("Sets the size reserved for pg_stat_activity.current_query, in bytes."),
1949                         NULL,
1950                 },
1951                 &pgstat_track_activity_query_size,
1952                 1024, 100, 102400, NULL, NULL
1953         },
1954
1955         /* End-of-list marker */
1956         {
1957                 {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL
1958         }
1959 };
1960
1961
1962 static struct config_real ConfigureNamesReal[] =
1963 {
1964         {
1965                 {"seq_page_cost", PGC_USERSET, QUERY_TUNING_COST,
1966                         gettext_noop("Sets the planner's estimate of the cost of a "
1967                                                  "sequentially fetched disk page."),
1968                         NULL
1969                 },
1970                 &seq_page_cost,
1971                 DEFAULT_SEQ_PAGE_COST, 0, DBL_MAX, NULL, NULL
1972         },
1973         {
1974                 {"random_page_cost", PGC_USERSET, QUERY_TUNING_COST,
1975                         gettext_noop("Sets the planner's estimate of the cost of a "
1976                                                  "nonsequentially fetched disk page."),
1977                         NULL
1978                 },
1979                 &random_page_cost,
1980                 DEFAULT_RANDOM_PAGE_COST, 0, DBL_MAX, NULL, NULL
1981         },
1982         {
1983                 {"cpu_tuple_cost", PGC_USERSET, QUERY_TUNING_COST,
1984                         gettext_noop("Sets the planner's estimate of the cost of "
1985                                                  "processing each tuple (row)."),
1986                         NULL
1987                 },
1988                 &cpu_tuple_cost,
1989                 DEFAULT_CPU_TUPLE_COST, 0, DBL_MAX, NULL, NULL
1990         },
1991         {
1992                 {"cpu_index_tuple_cost", PGC_USERSET, QUERY_TUNING_COST,
1993                         gettext_noop("Sets the planner's estimate of the cost of "
1994                                                  "processing each index entry during an index scan."),
1995                         NULL
1996                 },
1997                 &cpu_index_tuple_cost,
1998                 DEFAULT_CPU_INDEX_TUPLE_COST, 0, DBL_MAX, NULL, NULL
1999         },
2000         {
2001                 {"cpu_operator_cost", PGC_USERSET, QUERY_TUNING_COST,
2002                         gettext_noop("Sets the planner's estimate of the cost of "
2003                                                  "processing each operator or function call."),
2004                         NULL
2005                 },
2006                 &cpu_operator_cost,
2007                 DEFAULT_CPU_OPERATOR_COST, 0, DBL_MAX, NULL, NULL
2008         },
2009
2010         {
2011                 {"cursor_tuple_fraction", PGC_USERSET, QUERY_TUNING_OTHER,
2012                         gettext_noop("Sets the planner's estimate of the fraction of "
2013                                                  "a cursor's rows that will be retrieved."),
2014                         NULL
2015                 },
2016                 &cursor_tuple_fraction,
2017                 DEFAULT_CURSOR_TUPLE_FRACTION, 0.0, 1.0, NULL, NULL
2018         },
2019
2020         {
2021                 {"geqo_selection_bias", PGC_USERSET, QUERY_TUNING_GEQO,
2022                         gettext_noop("GEQO: selective pressure within the population."),
2023                         NULL
2024                 },
2025                 &Geqo_selection_bias,
2026                 DEFAULT_GEQO_SELECTION_BIAS, MIN_GEQO_SELECTION_BIAS,
2027                 MAX_GEQO_SELECTION_BIAS, NULL, NULL
2028         },
2029         {
2030                 {"geqo_seed", PGC_USERSET, QUERY_TUNING_GEQO,
2031                         gettext_noop("GEQO: seed for random path selection."),
2032                         NULL
2033                 },
2034                 &Geqo_seed,
2035                 0.0, 0.0, 1.0, NULL, NULL
2036         },
2037
2038         {
2039                 {"bgwriter_lru_multiplier", PGC_SIGHUP, RESOURCES,
2040                         gettext_noop("Multiple of the average buffer usage to free per round."),
2041                         NULL
2042                 },
2043                 &bgwriter_lru_multiplier,
2044                 2.0, 0.0, 10.0, NULL, NULL
2045         },
2046
2047         {
2048                 {"seed", PGC_USERSET, UNGROUPED,
2049                         gettext_noop("Sets the seed for random-number generation."),
2050                         NULL,
2051                         GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2052                 },
2053                 &phony_random_seed,
2054                 0.0, -1.0, 1.0, assign_random_seed, show_random_seed
2055         },
2056
2057         {
2058                 {"autovacuum_vacuum_scale_factor", PGC_SIGHUP, AUTOVACUUM,
2059                         gettext_noop("Number of tuple updates or deletes prior to vacuum as a fraction of reltuples."),
2060                         NULL
2061                 },
2062                 &autovacuum_vac_scale,
2063                 0.2, 0.0, 100.0, NULL, NULL
2064         },
2065         {
2066                 {"autovacuum_analyze_scale_factor", PGC_SIGHUP, AUTOVACUUM,
2067                         gettext_noop("Number of tuple inserts, updates or deletes prior to analyze as a fraction of reltuples."),
2068                         NULL
2069                 },
2070                 &autovacuum_anl_scale,
2071                 0.1, 0.0, 100.0, NULL, NULL
2072         },
2073
2074         {
2075                 {"checkpoint_completion_target", PGC_SIGHUP, WAL_CHECKPOINTS,
2076                         gettext_noop("Time spent flushing dirty buffers during checkpoint, as fraction of checkpoint interval."),
2077                         NULL
2078                 },
2079                 &CheckPointCompletionTarget,
2080                 0.5, 0.0, 1.0, NULL, NULL
2081         },
2082
2083         /* End-of-list marker */
2084         {
2085                 {NULL, 0, 0, NULL, NULL}, NULL, 0.0, 0.0, 0.0, NULL, NULL
2086         }
2087 };
2088
2089
2090 static struct config_string ConfigureNamesString[] =
2091 {
2092         {
2093                 {"archive_command", PGC_SIGHUP, WAL_SETTINGS,
2094                         gettext_noop("Sets the shell command that will be called to archive a WAL file."),
2095                         NULL
2096                 },
2097                 &XLogArchiveCommand,
2098                 "", NULL, show_archive_command
2099         },
2100
2101         {
2102                 {"client_encoding", PGC_USERSET, CLIENT_CONN_LOCALE,
2103                         gettext_noop("Sets the client's character set encoding."),
2104                         NULL,
2105                         GUC_IS_NAME | GUC_REPORT
2106                 },
2107                 &client_encoding_string,
2108                 "SQL_ASCII", assign_client_encoding, NULL
2109         },
2110
2111         {
2112                 {"log_line_prefix", PGC_SIGHUP, LOGGING_WHAT,
2113                         gettext_noop("Controls information prefixed to each log line."),
2114                         gettext_noop("If blank, no prefix is used.")
2115                 },
2116                 &Log_line_prefix,
2117                 "", NULL, NULL
2118         },
2119
2120         {
2121                 {"log_timezone", PGC_SIGHUP, LOGGING_WHAT,
2122                         gettext_noop("Sets the time zone to use in log messages."),
2123                         NULL
2124                 },
2125                 &log_timezone_string,
2126                 "UNKNOWN", assign_log_timezone, show_log_timezone
2127         },
2128
2129         {
2130                 {"DateStyle", PGC_USERSET, CLIENT_CONN_LOCALE,
2131                         gettext_noop("Sets the display format for date and time values."),
2132                         gettext_noop("Also controls interpretation of ambiguous "
2133                                                  "date inputs."),
2134                         GUC_LIST_INPUT | GUC_REPORT
2135                 },
2136                 &datestyle_string,
2137                 "ISO, MDY", assign_datestyle, NULL
2138         },
2139
2140         {
2141                 {"default_tablespace", PGC_USERSET, CLIENT_CONN_STATEMENT,
2142                         gettext_noop("Sets the default tablespace to create tables and indexes in."),
2143                         gettext_noop("An empty string selects the database's default tablespace."),
2144                         GUC_IS_NAME
2145                 },
2146                 &default_tablespace,
2147                 "", assign_default_tablespace, NULL
2148         },
2149
2150         {
2151                 {"temp_tablespaces", PGC_USERSET, CLIENT_CONN_STATEMENT,
2152                         gettext_noop("Sets the tablespace(s) to use for temporary tables and sort files."),
2153                         NULL,
2154                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2155                 },
2156                 &temp_tablespaces,
2157                 "", assign_temp_tablespaces, NULL
2158         },
2159
2160         {
2161                 {"dynamic_library_path", PGC_SUSET, CLIENT_CONN_OTHER,
2162                         gettext_noop("Sets the path for dynamically loadable modules."),
2163                         gettext_noop("If a dynamically loadable module needs to be opened and "
2164                                                  "the specified name does not have a directory component (i.e., the "
2165                                                  "name does not contain a slash), the system will search this path for "
2166                                                  "the specified file."),
2167                         GUC_SUPERUSER_ONLY
2168                 },
2169                 &Dynamic_library_path,
2170                 "$libdir", NULL, NULL
2171         },
2172
2173         {
2174                 {"krb_server_keyfile", PGC_SIGHUP, CONN_AUTH_SECURITY,
2175                         gettext_noop("Sets the location of the Kerberos server key file."),
2176                         NULL,
2177                         GUC_SUPERUSER_ONLY
2178                 },
2179                 &pg_krb_server_keyfile,
2180                 PG_KRB_SRVTAB, NULL, NULL
2181         },
2182
2183         {
2184                 {"krb_srvname", PGC_SIGHUP, CONN_AUTH_SECURITY,
2185                         gettext_noop("Sets the name of the Kerberos service."),
2186                         NULL
2187                 },
2188                 &pg_krb_srvnam,
2189                 PG_KRB_SRVNAM, NULL, NULL
2190         },
2191
2192         {
2193                 {"bonjour_name", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2194                         gettext_noop("Sets the Bonjour broadcast service name."),
2195                         NULL
2196                 },
2197                 &bonjour_name,
2198                 "", NULL, NULL
2199         },
2200
2201         /* See main.c about why defaults for LC_foo are not all alike */
2202
2203         {
2204                 {"lc_collate", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2205                         gettext_noop("Shows the collation order locale."),
2206                         NULL,
2207                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2208                 },
2209                 &locale_collate,
2210                 "C", NULL, NULL
2211         },
2212
2213         {
2214                 {"lc_ctype", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2215                         gettext_noop("Shows the character classification and case conversion locale."),
2216                         NULL,
2217                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2218                 },
2219                 &locale_ctype,
2220                 "C", NULL, NULL
2221         },
2222
2223         {
2224                 {"lc_messages", PGC_SUSET, CLIENT_CONN_LOCALE,
2225                         gettext_noop("Sets the language in which messages are displayed."),
2226                         NULL
2227                 },
2228                 &locale_messages,
2229                 "", locale_messages_assign, NULL
2230         },
2231
2232         {
2233                 {"lc_monetary", PGC_USERSET, CLIENT_CONN_LOCALE,
2234                         gettext_noop("Sets the locale for formatting monetary amounts."),
2235                         NULL
2236                 },
2237                 &locale_monetary,
2238                 "C", locale_monetary_assign, NULL
2239         },
2240
2241         {
2242                 {"lc_numeric", PGC_USERSET, CLIENT_CONN_LOCALE,
2243                         gettext_noop("Sets the locale for formatting numbers."),
2244                         NULL
2245                 },
2246                 &locale_numeric,
2247                 "C", locale_numeric_assign, NULL
2248         },
2249
2250         {
2251                 {"lc_time", PGC_USERSET, CLIENT_CONN_LOCALE,
2252                         gettext_noop("Sets the locale for formatting date and time values."),
2253                         NULL
2254                 },
2255                 &locale_time,
2256                 "C", locale_time_assign, NULL
2257         },
2258
2259         {
2260                 {"shared_preload_libraries", PGC_POSTMASTER, RESOURCES_KERNEL,
2261                         gettext_noop("Lists shared libraries to preload into server."),
2262                         NULL,
2263                         GUC_LIST_INPUT | GUC_LIST_QUOTE | GUC_SUPERUSER_ONLY
2264                 },
2265                 &shared_preload_libraries_string,
2266                 "", NULL, NULL
2267         },
2268
2269         {
2270                 {"local_preload_libraries", PGC_BACKEND, CLIENT_CONN_OTHER,
2271                         gettext_noop("Lists shared libraries to preload into each backend."),
2272                         NULL,
2273                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2274                 },
2275                 &local_preload_libraries_string,
2276                 "", NULL, NULL
2277         },
2278
2279         {
2280                 {"search_path", PGC_USERSET, CLIENT_CONN_STATEMENT,
2281                         gettext_noop("Sets the schema search order for names that are not schema-qualified."),
2282                         NULL,
2283                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2284                 },
2285                 &namespace_search_path,
2286                 "\"$user\",public", assign_search_path, NULL
2287         },
2288
2289         {
2290                 /* Can't be set in postgresql.conf */
2291                 {"server_encoding", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2292                         gettext_noop("Sets the server (database) character set encoding."),
2293                         NULL,
2294                         GUC_IS_NAME | GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2295                 },
2296                 &server_encoding_string,
2297                 "SQL_ASCII", NULL, NULL
2298         },
2299
2300         {
2301                 /* Can't be set in postgresql.conf */
2302                 {"server_version", PGC_INTERNAL, PRESET_OPTIONS,
2303                         gettext_noop("Shows the server version."),
2304                         NULL,
2305                         GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2306                 },
2307                 &server_version_string,
2308                 PG_VERSION, NULL, NULL
2309         },
2310
2311         {
2312                 /* Not for general use --- used by SET ROLE */
2313                 {"role", PGC_USERSET, UNGROUPED,
2314                         gettext_noop("Sets the current role."),
2315                         NULL,
2316                         GUC_IS_NAME | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2317                 },
2318                 &role_string,
2319                 "none", assign_role, show_role
2320         },
2321
2322         {
2323                 /* Not for general use --- used by SET SESSION AUTHORIZATION */
2324                 {"session_authorization", PGC_USERSET, UNGROUPED,
2325                         gettext_noop("Sets the session user name."),
2326                         NULL,
2327                         GUC_IS_NAME | GUC_REPORT | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2328                 },
2329                 &session_authorization_string,
2330                 NULL, assign_session_authorization, show_session_authorization
2331         },
2332
2333         {
2334                 {"log_destination", PGC_SIGHUP, LOGGING_WHERE,
2335                         gettext_noop("Sets the destination for server log output."),
2336                         gettext_noop("Valid values are combinations of \"stderr\", "
2337                                                  "\"syslog\", \"csvlog\", and \"eventlog\", "
2338                                                  "depending on the platform."),
2339                         GUC_LIST_INPUT
2340                 },
2341                 &log_destination_string,
2342                 "stderr", assign_log_destination, NULL
2343         },
2344         {
2345                 {"log_directory", PGC_SIGHUP, LOGGING_WHERE,
2346                         gettext_noop("Sets the destination directory for log files."),
2347                         gettext_noop("Can be specified as relative to the data directory "
2348                                                  "or as absolute path."),
2349                         GUC_SUPERUSER_ONLY
2350                 },
2351                 &Log_directory,
2352                 "pg_log", assign_canonical_path, NULL
2353         },
2354         {
2355                 {"log_filename", PGC_SIGHUP, LOGGING_WHERE,
2356                         gettext_noop("Sets the file name pattern for log files."),
2357                         NULL,
2358                         GUC_SUPERUSER_ONLY
2359                 },
2360                 &Log_filename,
2361                 "postgresql-%Y-%m-%d_%H%M%S.log", NULL, NULL
2362         },
2363
2364 #ifdef HAVE_SYSLOG
2365         {
2366                 {"syslog_ident", PGC_SIGHUP, LOGGING_WHERE,
2367                         gettext_noop("Sets the program name used to identify PostgreSQL "
2368                                                  "messages in syslog."),
2369                         NULL
2370                 },
2371                 &syslog_ident_str,
2372                 "postgres", assign_syslog_ident, NULL
2373         },
2374 #endif
2375
2376         {
2377                 {"TimeZone", PGC_USERSET, CLIENT_CONN_LOCALE,
2378                         gettext_noop("Sets the time zone for displaying and interpreting time stamps."),
2379                         NULL,
2380                         GUC_REPORT
2381                 },
2382                 &timezone_string,
2383                 "UNKNOWN", assign_timezone, show_timezone
2384         },
2385         {
2386                 {"timezone_abbreviations", PGC_USERSET, CLIENT_CONN_LOCALE,
2387                         gettext_noop("Selects a file of time zone abbreviations."),
2388                         NULL
2389                 },
2390                 &timezone_abbreviations_string,
2391                 "UNKNOWN", assign_timezone_abbreviations, NULL
2392         },
2393
2394         {
2395                 {"transaction_isolation", PGC_USERSET, CLIENT_CONN_STATEMENT,
2396                         gettext_noop("Sets the current transaction's isolation level."),
2397                         NULL,
2398                         GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2399                 },
2400                 &XactIsoLevel_string,
2401                 NULL, assign_XactIsoLevel, show_XactIsoLevel
2402         },
2403
2404         {
2405                 {"unix_socket_group", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2406                         gettext_noop("Sets the owning group of the Unix-domain socket."),
2407                         gettext_noop("The owning user of the socket is always the user "
2408                                                  "that starts the server.")
2409                 },
2410                 &Unix_socket_group,
2411                 "", NULL, NULL
2412         },
2413
2414         {
2415                 {"unix_socket_directory", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2416                         gettext_noop("Sets the directory where the Unix-domain socket will be created."),
2417                         NULL,
2418                         GUC_SUPERUSER_ONLY
2419                 },
2420                 &UnixSocketDir,
2421                 "", assign_canonical_path, NULL
2422         },
2423
2424         {
2425                 {"listen_addresses", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2426                         gettext_noop("Sets the host name or IP address(es) to listen to."),
2427                         NULL,
2428                         GUC_LIST_INPUT
2429                 },
2430                 &ListenAddresses,
2431                 "localhost", NULL, NULL
2432         },
2433
2434         {
2435                 {"custom_variable_classes", PGC_SIGHUP, CUSTOM_OPTIONS,
2436                         gettext_noop("Sets the list of known custom variable classes."),
2437                         NULL,
2438                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2439                 },
2440                 &custom_variable_classes,
2441                 NULL, assign_custom_variable_classes, NULL
2442         },
2443
2444         {
2445                 {"data_directory", PGC_POSTMASTER, FILE_LOCATIONS,
2446                         gettext_noop("Sets the server's data directory."),
2447                         NULL,
2448                         GUC_SUPERUSER_ONLY
2449                 },
2450                 &data_directory,
2451                 NULL, NULL, NULL
2452         },
2453
2454         {
2455                 {"config_file", PGC_POSTMASTER, FILE_LOCATIONS,
2456                         gettext_noop("Sets the server's main configuration file."),
2457                         NULL,
2458                         GUC_DISALLOW_IN_FILE | GUC_SUPERUSER_ONLY
2459                 },
2460                 &ConfigFileName,
2461                 NULL, NULL, NULL
2462         },
2463
2464         {
2465                 {"hba_file", PGC_POSTMASTER, FILE_LOCATIONS,
2466                         gettext_noop("Sets the server's \"hba\" configuration file."),
2467                         NULL,
2468                         GUC_SUPERUSER_ONLY
2469                 },
2470                 &HbaFileName,
2471                 NULL, NULL, NULL
2472         },
2473
2474         {
2475                 {"ident_file", PGC_POSTMASTER, FILE_LOCATIONS,
2476                         gettext_noop("Sets the server's \"ident\" configuration file."),
2477                         NULL,
2478                         GUC_SUPERUSER_ONLY
2479                 },
2480                 &IdentFileName,
2481                 NULL, NULL, NULL
2482         },
2483
2484         {
2485                 {"external_pid_file", PGC_POSTMASTER, FILE_LOCATIONS,
2486                         gettext_noop("Writes the postmaster PID to the specified file."),
2487                         NULL,
2488                         GUC_SUPERUSER_ONLY
2489                 },
2490                 &external_pid_file,
2491                 NULL, assign_canonical_path, NULL
2492         },
2493
2494         {
2495                 {"stats_temp_directory", PGC_SIGHUP, STATS_COLLECTOR,
2496                         gettext_noop("Writes temporary statistics files to the specified directory."),
2497                         NULL,
2498                         GUC_SUPERUSER_ONLY
2499                 },
2500                 &pgstat_temp_directory,
2501                 "pg_stat_tmp", assign_pgstat_temp_directory, NULL
2502         },
2503
2504         {
2505                 {"default_text_search_config", PGC_USERSET, CLIENT_CONN_LOCALE,
2506                         gettext_noop("Sets default text search configuration."),
2507                         NULL
2508                 },
2509                 &TSCurrentConfig,
2510                 "pg_catalog.simple", assignTSCurrentConfig, NULL
2511         },
2512
2513 #ifdef USE_SSL
2514         {
2515                 {"ssl_ciphers", PGC_POSTMASTER, CONN_AUTH_SECURITY,
2516                         gettext_noop("Sets the list of allowed SSL ciphers."),
2517                         NULL,
2518                         GUC_SUPERUSER_ONLY
2519                 },
2520                 &SSLCipherSuites,
2521                 "ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH", NULL, NULL
2522         },
2523 #endif   /* USE_SSL */
2524
2525         /* End-of-list marker */
2526         {
2527                 {NULL, 0, 0, NULL, NULL}, NULL, NULL, NULL, NULL
2528         }
2529 };
2530
2531
2532 static struct config_enum ConfigureNamesEnum[] =
2533 {
2534         {
2535                 {"backslash_quote", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
2536                         gettext_noop("Sets whether \"\\'\" is allowed in string literals."),
2537                         NULL
2538                 },
2539                 &backslash_quote,
2540                 BACKSLASH_QUOTE_SAFE_ENCODING, backslash_quote_options, NULL, NULL
2541         },
2542
2543         {
2544                 {"client_min_messages", PGC_USERSET, LOGGING_WHEN,
2545                         gettext_noop("Sets the message levels that are sent to the client."),
2546                         gettext_noop("Each level includes all the levels that follow it. The later"
2547                                                  " the level, the fewer messages are sent.")
2548                 },
2549                 &client_min_messages,
2550                 NOTICE, client_message_level_options, NULL, NULL
2551         },
2552
2553         {
2554                 {"constraint_exclusion", PGC_USERSET, QUERY_TUNING_OTHER,
2555                         gettext_noop("Enables the planner to use constraints to optimize queries."),
2556                         gettext_noop("Table scans will be skipped if their constraints"
2557                                                  " guarantee that no rows match the query.")
2558                 },
2559                 &constraint_exclusion,
2560                 CONSTRAINT_EXCLUSION_PARTITION, constraint_exclusion_options,
2561                 NULL, NULL
2562         },
2563
2564         {
2565                 {"default_transaction_isolation", PGC_USERSET, CLIENT_CONN_STATEMENT,
2566                         gettext_noop("Sets the transaction isolation level of each new transaction."),
2567                         NULL
2568                 },
2569                 &DefaultXactIsoLevel,
2570                 XACT_READ_COMMITTED, isolation_level_options, NULL, NULL
2571         },
2572
2573         {
2574                 {"IntervalStyle", PGC_USERSET, CLIENT_CONN_LOCALE,
2575                         gettext_noop("Sets the display format for interval values."),
2576                         NULL,
2577                         GUC_REPORT
2578                 },
2579                 &IntervalStyle,
2580                 INTSTYLE_POSTGRES, intervalstyle_options, NULL, NULL
2581         },
2582
2583         {
2584                 {"log_error_verbosity", PGC_SUSET, LOGGING_WHEN,
2585                         gettext_noop("Sets the verbosity of logged messages."),
2586                         NULL
2587                 },
2588                 &Log_error_verbosity,
2589                 PGERROR_DEFAULT, log_error_verbosity_options, NULL, NULL
2590         },
2591
2592         {
2593                 {"log_min_messages", PGC_SUSET, LOGGING_WHEN,
2594                         gettext_noop("Sets the message levels that are logged."),
2595                         gettext_noop("Each level includes all the levels that follow it. The later"
2596                                                  " the level, the fewer messages are sent.")
2597                 },
2598                 &log_min_messages,
2599                 WARNING, server_message_level_options, NULL, NULL
2600         },
2601
2602         {
2603                 {"log_min_error_statement", PGC_SUSET, LOGGING_WHEN,
2604                         gettext_noop("Causes all statements generating error at or above this level to be logged."),
2605                         gettext_noop("Each level includes all the levels that follow it. The later"
2606                                                  " the level, the fewer messages are sent.")
2607                 },
2608                 &log_min_error_statement,
2609                 ERROR, server_message_level_options, NULL, NULL
2610         },
2611
2612         {
2613                 {"log_statement", PGC_SUSET, LOGGING_WHAT,
2614                         gettext_noop("Sets the type of statements logged."),
2615                         NULL
2616                 },
2617                 &log_statement,
2618                 LOGSTMT_NONE, log_statement_options, NULL, NULL
2619         },
2620
2621 #ifdef HAVE_SYSLOG
2622         {
2623                 {"syslog_facility", PGC_SIGHUP, LOGGING_WHERE,
2624                         gettext_noop("Sets the syslog \"facility\" to be used when syslog enabled."),
2625                         NULL
2626                 },
2627                 &syslog_facility,
2628                 LOG_LOCAL0, syslog_facility_options, assign_syslog_facility, NULL
2629         },
2630 #endif
2631
2632         {
2633                 {"regex_flavor", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
2634                         gettext_noop("Sets the regular expression \"flavor\"."),
2635                         NULL
2636                 },
2637                 &regex_flavor,
2638                 REG_ADVANCED, regex_flavor_options, NULL, NULL
2639         },
2640
2641         {
2642                 {"session_replication_role", PGC_SUSET, CLIENT_CONN_STATEMENT,
2643                         gettext_noop("Sets the session's behavior for triggers and rewrite rules."),
2644                         NULL
2645                 },
2646                 &SessionReplicationRole,
2647                 SESSION_REPLICATION_ROLE_ORIGIN, session_replication_role_options,
2648                 assign_session_replication_role, NULL
2649         },
2650
2651         {
2652                 {"track_functions", PGC_SUSET, STATS_COLLECTOR,
2653                         gettext_noop("Collects function-level statistics on database activity."),
2654                         NULL
2655                 },
2656                 &pgstat_track_functions,
2657                 TRACK_FUNC_OFF, track_function_options, NULL, NULL
2658         },
2659
2660         {
2661                 {"wal_sync_method", PGC_SIGHUP, WAL_SETTINGS,
2662                         gettext_noop("Selects the method used for forcing WAL updates to disk."),
2663                         NULL
2664                 },
2665                 &sync_method,
2666                 DEFAULT_SYNC_METHOD, sync_method_options,
2667                 assign_xlog_sync_method, NULL
2668         },
2669
2670         {
2671                 {"xmlbinary", PGC_USERSET, CLIENT_CONN_STATEMENT,
2672                         gettext_noop("Sets how binary values are to be encoded in XML."),
2673                         NULL
2674                 },
2675                 &xmlbinary,
2676                 XMLBINARY_BASE64, xmlbinary_options, NULL, NULL
2677         },
2678
2679         {
2680                 {"xmloption", PGC_USERSET, CLIENT_CONN_STATEMENT,
2681                         gettext_noop("Sets whether XML data in implicit parsing and serialization "
2682                                                  "operations is to be considered as documents or content fragments."),
2683                         NULL
2684                 },
2685                 &xmloption,
2686                 XMLOPTION_CONTENT, xmloption_options, NULL, NULL
2687         },
2688
2689
2690         /* End-of-list marker */
2691         {
2692                 {NULL, 0, 0, NULL, NULL}, NULL, 0, NULL, NULL, NULL
2693         }
2694 };
2695
2696 /******** end of options list ********/
2697
2698
2699 /*
2700  * To allow continued support of obsolete names for GUC variables, we apply
2701  * the following mappings to any unrecognized name.  Note that an old name
2702  * should be mapped to a new one only if the new variable has very similar
2703  * semantics to the old.
2704  */
2705 static const char *const map_old_guc_names[] = {
2706         "sort_mem", "work_mem",
2707         "vacuum_mem", "maintenance_work_mem",
2708         NULL
2709 };
2710
2711
2712 /*
2713  * Actual lookup of variables is done through this single, sorted array.
2714  */
2715 static struct config_generic **guc_variables;
2716
2717 /* Current number of variables contained in the vector */
2718 static int      num_guc_variables;
2719
2720 /* Vector capacity */
2721 static int      size_guc_variables;
2722
2723
2724 static bool guc_dirty;                  /* TRUE if need to do commit/abort work */
2725
2726 static bool reporting_enabled;  /* TRUE to enable GUC_REPORT */
2727
2728 static int      GUCNestLevel = 0;       /* 1 when in main transaction */
2729
2730
2731 static int      guc_var_compare(const void *a, const void *b);
2732 static int      guc_name_compare(const char *namea, const char *nameb);
2733 static void InitializeOneGUCOption(struct config_generic * gconf);
2734 static void push_old_value(struct config_generic * gconf, GucAction action);
2735 static void ReportGUCOption(struct config_generic * record);
2736 static void ShowGUCConfigOption(const char *name, DestReceiver *dest);
2737 static void ShowAllGUCConfig(DestReceiver *dest);
2738 static char *_ShowOption(struct config_generic * record, bool use_units);
2739 static bool is_newvalue_equal(struct config_generic * record, const char *newvalue);
2740
2741
2742 /*
2743  * Some infrastructure for checking malloc/strdup/realloc calls
2744  */
2745 static void *
2746 guc_malloc(int elevel, size_t size)
2747 {
2748         void       *data;
2749
2750         data = malloc(size);
2751         if (data == NULL)
2752                 ereport(elevel,
2753                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2754                                  errmsg("out of memory")));
2755         return data;
2756 }
2757
2758 static void *
2759 guc_realloc(int elevel, void *old, size_t size)
2760 {
2761         void       *data;
2762
2763         data = realloc(old, size);
2764         if (data == NULL)
2765                 ereport(elevel,
2766                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2767                                  errmsg("out of memory")));
2768         return data;
2769 }
2770
2771 static char *
2772 guc_strdup(int elevel, const char *src)
2773 {
2774         char       *data;
2775
2776         data = strdup(src);
2777         if (data == NULL)
2778                 ereport(elevel,
2779                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2780                                  errmsg("out of memory")));
2781         return data;
2782 }
2783
2784
2785 /*
2786  * Support for assigning to a field of a string GUC item.  Free the prior
2787  * value if it's not referenced anywhere else in the item (including stacked
2788  * states).
2789  */
2790 static void
2791 set_string_field(struct config_string * conf, char **field, char *newval)
2792 {
2793         char       *oldval = *field;
2794         GucStack   *stack;
2795
2796         /* Do the assignment */
2797         *field = newval;
2798
2799         /* Exit if any duplicate references, or if old value was NULL anyway */
2800         if (oldval == NULL ||
2801                 oldval == *(conf->variable) ||
2802                 oldval == conf->reset_val ||
2803                 oldval == conf->boot_val)
2804                 return;
2805         for (stack = conf->gen.stack; stack; stack = stack->prev)
2806         {
2807                 if (oldval == stack->prior.stringval ||
2808                         oldval == stack->masked.stringval)
2809                         return;
2810         }
2811
2812         /* Not used anymore, so free it */
2813         free(oldval);
2814 }
2815
2816 /*
2817  * Detect whether strval is referenced anywhere in a GUC string item
2818  */
2819 static bool
2820 string_field_used(struct config_string * conf, char *strval)
2821 {
2822         GucStack   *stack;
2823
2824         if (strval == *(conf->variable) ||
2825                 strval == conf->reset_val ||
2826                 strval == conf->boot_val)
2827                 return true;
2828         for (stack = conf->gen.stack; stack; stack = stack->prev)
2829         {
2830                 if (strval == stack->prior.stringval ||
2831                         strval == stack->masked.stringval)
2832                         return true;
2833         }
2834         return false;
2835 }
2836
2837 /*
2838  * Support for copying a variable's active value into a stack entry
2839  */
2840 static void
2841 set_stack_value(struct config_generic * gconf, union config_var_value * val)
2842 {
2843         switch (gconf->vartype)
2844         {
2845                 case PGC_BOOL:
2846                         val->boolval =
2847                                 *((struct config_bool *) gconf)->variable;
2848                         break;
2849                 case PGC_INT:
2850                         val->intval =
2851                                 *((struct config_int *) gconf)->variable;
2852                         break;
2853                 case PGC_REAL:
2854                         val->realval =
2855                                 *((struct config_real *) gconf)->variable;
2856                         break;
2857                 case PGC_STRING:
2858                         /* we assume stringval is NULL if not valid */
2859                         set_string_field((struct config_string *) gconf,
2860                                                          &(val->stringval),
2861                                                          *((struct config_string *) gconf)->variable);
2862                         break;
2863                 case PGC_ENUM:
2864                         val->enumval =
2865                                 *((struct config_enum *) gconf)->variable;
2866                         break;
2867         }
2868 }
2869
2870 /*
2871  * Support for discarding a no-longer-needed value in a stack entry
2872  */
2873 static void
2874 discard_stack_value(struct config_generic * gconf, union config_var_value * val)
2875 {
2876         switch (gconf->vartype)
2877         {
2878                 case PGC_BOOL:
2879                 case PGC_INT:
2880                 case PGC_REAL:
2881                 case PGC_ENUM:
2882                         /* no need to do anything */
2883                         break;
2884                 case PGC_STRING:
2885                         set_string_field((struct config_string *) gconf,
2886                                                          &(val->stringval),
2887                                                          NULL);
2888                         break;
2889         }
2890 }
2891
2892
2893 /*
2894  * Fetch the sorted array pointer (exported for help_config.c's use ONLY)
2895  */
2896 struct config_generic **
2897 get_guc_variables(void)
2898 {
2899         return guc_variables;
2900 }
2901
2902
2903 /*
2904  * Build the sorted array.      This is split out so that it could be
2905  * re-executed after startup (eg, we could allow loadable modules to
2906  * add vars, and then we'd need to re-sort).
2907  */
2908 void
2909 build_guc_variables(void)
2910 {
2911         int                     size_vars;
2912         int                     num_vars = 0;
2913         struct config_generic **guc_vars;
2914         int                     i;
2915
2916         for (i = 0; ConfigureNamesBool[i].gen.name; i++)
2917         {
2918                 struct config_bool *conf = &ConfigureNamesBool[i];
2919
2920                 /* Rather than requiring vartype to be filled in by hand, do this: */
2921                 conf->gen.vartype = PGC_BOOL;
2922                 num_vars++;
2923         }
2924
2925         for (i = 0; ConfigureNamesInt[i].gen.name; i++)
2926         {
2927                 struct config_int *conf = &ConfigureNamesInt[i];
2928
2929                 conf->gen.vartype = PGC_INT;
2930                 num_vars++;
2931         }
2932
2933         for (i = 0; ConfigureNamesReal[i].gen.name; i++)
2934         {
2935                 struct config_real *conf = &ConfigureNamesReal[i];
2936
2937                 conf->gen.vartype = PGC_REAL;
2938                 num_vars++;
2939         }
2940
2941         for (i = 0; ConfigureNamesString[i].gen.name; i++)
2942         {
2943                 struct config_string *conf = &ConfigureNamesString[i];
2944
2945                 conf->gen.vartype = PGC_STRING;
2946                 num_vars++;
2947         }
2948
2949         for (i = 0; ConfigureNamesEnum[i].gen.name; i++)
2950         {
2951                 struct config_enum *conf = &ConfigureNamesEnum[i];
2952
2953                 conf->gen.vartype = PGC_ENUM;
2954                 num_vars++;
2955         }
2956
2957         /*
2958          * Create table with 20% slack
2959          */
2960         size_vars = num_vars + num_vars / 4;
2961
2962         guc_vars = (struct config_generic **)
2963                 guc_malloc(FATAL, size_vars * sizeof(struct config_generic *));
2964
2965         num_vars = 0;
2966
2967         for (i = 0; ConfigureNamesBool[i].gen.name; i++)
2968                 guc_vars[num_vars++] = &ConfigureNamesBool[i].gen;
2969
2970         for (i = 0; ConfigureNamesInt[i].gen.name; i++)
2971                 guc_vars[num_vars++] = &ConfigureNamesInt[i].gen;
2972
2973         for (i = 0; ConfigureNamesReal[i].gen.name; i++)
2974                 guc_vars[num_vars++] = &ConfigureNamesReal[i].gen;
2975
2976         for (i = 0; ConfigureNamesString[i].gen.name; i++)
2977                 guc_vars[num_vars++] = &ConfigureNamesString[i].gen;
2978
2979         for (i = 0; ConfigureNamesEnum[i].gen.name; i++)
2980                 guc_vars[num_vars++] = &ConfigureNamesEnum[i].gen;
2981
2982         if (guc_variables)
2983                 free(guc_variables);
2984         guc_variables = guc_vars;
2985         num_guc_variables = num_vars;
2986         size_guc_variables = size_vars;
2987         qsort((void *) guc_variables, num_guc_variables,
2988                   sizeof(struct config_generic *), guc_var_compare);
2989 }
2990
2991 /*
2992  * Add a new GUC variable to the list of known variables. The
2993  * list is expanded if needed.
2994  */
2995 static bool
2996 add_guc_variable(struct config_generic * var, int elevel)
2997 {
2998         if (num_guc_variables + 1 >= size_guc_variables)
2999         {
3000                 /*
3001                  * Increase the vector by 25%
3002                  */
3003                 int                     size_vars = size_guc_variables + size_guc_variables / 4;
3004                 struct config_generic **guc_vars;
3005
3006                 if (size_vars == 0)
3007                 {
3008                         size_vars = 100;
3009                         guc_vars = (struct config_generic **)
3010                                 guc_malloc(elevel, size_vars * sizeof(struct config_generic *));
3011                 }
3012                 else
3013                 {
3014                         guc_vars = (struct config_generic **)
3015                                 guc_realloc(elevel, guc_variables, size_vars * sizeof(struct config_generic *));
3016                 }
3017
3018                 if (guc_vars == NULL)
3019                         return false;           /* out of memory */
3020
3021                 guc_variables = guc_vars;
3022                 size_guc_variables = size_vars;
3023         }
3024         guc_variables[num_guc_variables++] = var;
3025         qsort((void *) guc_variables, num_guc_variables,
3026                   sizeof(struct config_generic *), guc_var_compare);
3027         return true;
3028 }
3029
3030 /*
3031  * Create and add a placeholder variable. It's presumed to belong
3032  * to a valid custom variable class at this point.
3033  */
3034 static struct config_generic *
3035 add_placeholder_variable(const char *name, int elevel)
3036 {
3037         size_t          sz = sizeof(struct config_string) + sizeof(char *);
3038         struct config_string *var;
3039         struct config_generic *gen;
3040
3041         var = (struct config_string *) guc_malloc(elevel, sz);
3042         if (var == NULL)
3043                 return NULL;
3044         memset(var, 0, sz);
3045         gen = &var->gen;
3046
3047         gen->name = guc_strdup(elevel, name);
3048         if (gen->name == NULL)
3049         {
3050                 free(var);
3051                 return NULL;
3052         }
3053
3054         gen->context = PGC_USERSET;
3055         gen->group = CUSTOM_OPTIONS;
3056         gen->short_desc = "GUC placeholder variable";
3057         gen->flags = GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE | GUC_CUSTOM_PLACEHOLDER;
3058         gen->vartype = PGC_STRING;
3059
3060         /*
3061          * The char* is allocated at the end of the struct since we have no
3062          * 'static' place to point to.  Note that the current value, as well as
3063          * the boot and reset values, start out NULL.
3064          */
3065         var->variable = (char **) (var + 1);
3066
3067         if (!add_guc_variable((struct config_generic *) var, elevel))
3068         {
3069                 free((void *) gen->name);
3070                 free(var);
3071                 return NULL;
3072         }
3073
3074         return gen;
3075 }
3076
3077 /*
3078  * Detect whether the portion of "name" before dotPos matches any custom
3079  * variable class name listed in custom_var_classes.  The latter must be
3080  * formatted the way that assign_custom_variable_classes does it, ie,
3081  * no whitespace.  NULL is valid for custom_var_classes.
3082  */
3083 static bool
3084 is_custom_class(const char *name, int dotPos, const char *custom_var_classes)
3085 {
3086         bool            result = false;
3087         const char *ccs = custom_var_classes;
3088
3089         if (ccs != NULL)
3090         {
3091                 const char *start = ccs;
3092
3093                 for (;; ++ccs)
3094                 {
3095                         char            c = *ccs;
3096
3097                         if (c == '\0' || c == ',')
3098                         {
3099                                 if (dotPos == ccs - start && strncmp(start, name, dotPos) == 0)
3100                                 {
3101                                         result = true;
3102                                         break;
3103                                 }
3104                                 if (c == '\0')
3105                                         break;
3106                                 start = ccs + 1;
3107                         }
3108                 }
3109         }
3110         return result;
3111 }
3112
3113 /*
3114  * Look up option NAME.  If it exists, return a pointer to its record,
3115  * else return NULL.  If create_placeholders is TRUE, we'll create a
3116  * placeholder record for a valid-looking custom variable name.
3117  */
3118 static struct config_generic *
3119 find_option(const char *name, bool create_placeholders, int elevel)
3120 {
3121         const char **key = &name;
3122         struct config_generic **res;
3123         int                     i;
3124
3125         Assert(name);
3126
3127         /*
3128          * By equating const char ** with struct config_generic *, we are assuming
3129          * the name field is first in config_generic.
3130          */
3131         res = (struct config_generic **) bsearch((void *) &key,
3132                                                                                          (void *) guc_variables,
3133                                                                                          num_guc_variables,
3134                                                                                          sizeof(struct config_generic *),
3135                                                                                          guc_var_compare);
3136         if (res)
3137                 return *res;
3138
3139         /*
3140          * See if the name is an obsolete name for a variable.  We assume that the
3141          * set of supported old names is short enough that a brute-force search is
3142          * the best way.
3143          */
3144         for (i = 0; map_old_guc_names[i] != NULL; i += 2)
3145         {
3146                 if (guc_name_compare(name, map_old_guc_names[i]) == 0)
3147                         return find_option(map_old_guc_names[i + 1], false, elevel);
3148         }
3149
3150         if (create_placeholders)
3151         {
3152                 /*
3153                  * Check if the name is qualified, and if so, check if the qualifier
3154                  * matches any custom variable class.  If so, add a placeholder.
3155                  */
3156                 const char *dot = strchr(name, GUC_QUALIFIER_SEPARATOR);
3157
3158                 if (dot != NULL &&
3159                         is_custom_class(name, dot - name, custom_variable_classes))
3160                         return add_placeholder_variable(name, elevel);
3161         }
3162
3163         /* Unknown name */
3164         return NULL;
3165 }
3166
3167
3168 /*
3169  * comparator for qsorting and bsearching guc_variables array
3170  */
3171 static int
3172 guc_var_compare(const void *a, const void *b)
3173 {
3174         struct config_generic *confa = *(struct config_generic **) a;
3175         struct config_generic *confb = *(struct config_generic **) b;
3176
3177         return guc_name_compare(confa->name, confb->name);
3178 }
3179
3180 /*
3181  * the bare comparison function for GUC names
3182  */
3183 static int
3184 guc_name_compare(const char *namea, const char *nameb)
3185 {
3186         /*
3187          * The temptation to use strcasecmp() here must be resisted, because the
3188          * array ordering has to remain stable across setlocale() calls. So, build
3189          * our own with a simple ASCII-only downcasing.
3190          */
3191         while (*namea && *nameb)
3192         {
3193                 char            cha = *namea++;
3194                 char            chb = *nameb++;
3195
3196                 if (cha >= 'A' && cha <= 'Z')
3197                         cha += 'a' - 'A';
3198                 if (chb >= 'A' && chb <= 'Z')
3199                         chb += 'a' - 'A';
3200                 if (cha != chb)
3201                         return cha - chb;
3202         }
3203         if (*namea)
3204                 return 1;                               /* a is longer */
3205         if (*nameb)
3206                 return -1;                              /* b is longer */
3207         return 0;
3208 }
3209
3210
3211 /*
3212  * Initialize GUC options during program startup.
3213  *
3214  * Note that we cannot read the config file yet, since we have not yet
3215  * processed command-line switches.
3216  */
3217 void
3218 InitializeGUCOptions(void)
3219 {
3220         int                     i;
3221         char       *env;
3222         long            stack_rlimit;
3223
3224         /*
3225          * Before log_line_prefix could possibly receive a nonempty setting, make
3226          * sure that timezone processing is minimally alive (see elog.c).
3227          */
3228         pg_timezone_pre_initialize();
3229
3230         /*
3231          * Build sorted array of all GUC variables.
3232          */
3233         build_guc_variables();
3234
3235         /*
3236          * Load all variables with their compiled-in defaults, and initialize
3237          * status fields as needed.
3238          */
3239         for (i = 0; i < num_guc_variables; i++)
3240         {
3241                 InitializeOneGUCOption(guc_variables[i]);
3242         }
3243
3244         guc_dirty = false;
3245
3246         reporting_enabled = false;
3247
3248         /*
3249          * Prevent any attempt to override the transaction modes from
3250          * non-interactive sources.
3251          */
3252         SetConfigOption("transaction_isolation", "default",
3253                                         PGC_POSTMASTER, PGC_S_OVERRIDE);
3254         SetConfigOption("transaction_read_only", "no",
3255                                         PGC_POSTMASTER, PGC_S_OVERRIDE);
3256
3257         /*
3258          * For historical reasons, some GUC parameters can receive defaults from
3259          * environment variables.  Process those settings.      NB: if you add or
3260          * remove anything here, see also ProcessConfigFile().
3261          */
3262
3263         env = getenv("PGPORT");
3264         if (env != NULL)
3265                 SetConfigOption("port", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3266
3267         env = getenv("PGDATESTYLE");
3268         if (env != NULL)
3269                 SetConfigOption("datestyle", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3270
3271         env = getenv("PGCLIENTENCODING");
3272         if (env != NULL)
3273                 SetConfigOption("client_encoding", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3274
3275         /*
3276          * rlimit isn't exactly an "environment variable", but it behaves about
3277          * the same.  If we can identify the platform stack depth rlimit, increase
3278          * default stack depth setting up to whatever is safe (but at most 2MB).
3279          */
3280         stack_rlimit = get_stack_depth_rlimit();
3281         if (stack_rlimit > 0)
3282         {
3283                 int                     new_limit = (stack_rlimit - STACK_DEPTH_SLOP) / 1024L;
3284
3285                 if (new_limit > 100)
3286                 {
3287                         char            limbuf[16];
3288
3289                         new_limit = Min(new_limit, 2048);
3290                         sprintf(limbuf, "%d", new_limit);
3291                         SetConfigOption("max_stack_depth", limbuf,
3292                                                         PGC_POSTMASTER, PGC_S_ENV_VAR);
3293                 }
3294         }
3295 }
3296
3297 /*
3298  * Initialize one GUC option variable to its compiled-in default.
3299  */
3300 static void
3301 InitializeOneGUCOption(struct config_generic * gconf)
3302 {
3303         gconf->status = 0;
3304         gconf->reset_source = PGC_S_DEFAULT;
3305         gconf->source = PGC_S_DEFAULT;
3306         gconf->stack = NULL;
3307         gconf->sourcefile = NULL;
3308         gconf->sourceline = 0;
3309
3310         switch (gconf->vartype)
3311         {
3312                 case PGC_BOOL:
3313                         {
3314                                 struct config_bool *conf = (struct config_bool *) gconf;
3315
3316                                 if (conf->assign_hook)
3317                                         if (!(*conf->assign_hook) (conf->boot_val, true,
3318                                                                                            PGC_S_DEFAULT))
3319                                                 elog(FATAL, "failed to initialize %s to %d",
3320                                                          conf->gen.name, (int) conf->boot_val);
3321                                 *conf->variable = conf->reset_val = conf->boot_val;
3322                                 break;
3323                         }
3324                 case PGC_INT:
3325                         {
3326                                 struct config_int *conf = (struct config_int *) gconf;
3327
3328                                 Assert(conf->boot_val >= conf->min);
3329                                 Assert(conf->boot_val <= conf->max);
3330                                 if (conf->assign_hook)
3331                                         if (!(*conf->assign_hook) (conf->boot_val, true,
3332                                                                                            PGC_S_DEFAULT))
3333                                                 elog(FATAL, "failed to initialize %s to %d",
3334                                                          conf->gen.name, conf->boot_val);
3335                                 *conf->variable = conf->reset_val = conf->boot_val;
3336                                 break;
3337                         }
3338                 case PGC_REAL:
3339                         {
3340                                 struct config_real *conf = (struct config_real *) gconf;
3341
3342                                 Assert(conf->boot_val >= conf->min);
3343                                 Assert(conf->boot_val <= conf->max);
3344                                 if (conf->assign_hook)
3345                                         if (!(*conf->assign_hook) (conf->boot_val, true,
3346                                                                                            PGC_S_DEFAULT))
3347                                                 elog(FATAL, "failed to initialize %s to %g",
3348                                                          conf->gen.name, conf->boot_val);
3349                                 *conf->variable = conf->reset_val = conf->boot_val;
3350                                 break;
3351                         }
3352                 case PGC_STRING:
3353                         {
3354                                 struct config_string *conf = (struct config_string *) gconf;
3355                                 char       *str;
3356
3357                                 *conf->variable = NULL;
3358                                 conf->reset_val = NULL;
3359
3360                                 if (conf->boot_val == NULL)
3361                                 {
3362                                         /* leave the value NULL, do not call assign hook */
3363                                         break;
3364                                 }
3365
3366                                 str = guc_strdup(FATAL, conf->boot_val);
3367                                 conf->reset_val = str;
3368
3369                                 if (conf->assign_hook)
3370                                 {
3371                                         const char *newstr;
3372
3373                                         newstr = (*conf->assign_hook) (str, true,
3374                                                                                                    PGC_S_DEFAULT);
3375                                         if (newstr == NULL)
3376                                         {
3377                                                 elog(FATAL, "failed to initialize %s to \"%s\"",
3378                                                          conf->gen.name, str);
3379                                         }
3380                                         else if (newstr != str)
3381                                         {
3382                                                 free(str);
3383
3384                                                 /*
3385                                                  * See notes in set_config_option about casting
3386                                                  */
3387                                                 str = (char *) newstr;
3388                                                 conf->reset_val = str;
3389                                         }
3390                                 }
3391                                 *conf->variable = str;
3392                                 break;
3393                         }
3394                 case PGC_ENUM:
3395                         {
3396                                 struct config_enum *conf = (struct config_enum *) gconf;
3397
3398                                 if (conf->assign_hook)
3399                                         if (!(*conf->assign_hook) (conf->boot_val, true,
3400                                                                                            PGC_S_DEFAULT))
3401                                                 elog(FATAL, "failed to initialize %s to %s",
3402                                                          conf->gen.name,
3403                                                   config_enum_lookup_by_value(conf, conf->boot_val));
3404                                 *conf->variable = conf->reset_val = conf->boot_val;
3405                                 break;
3406                         }
3407         }
3408 }
3409
3410
3411 /*
3412  * Select the configuration files and data directory to be used, and
3413  * do the initial read of postgresql.conf.
3414  *
3415  * This is called after processing command-line switches.
3416  *              userDoption is the -D switch value if any (NULL if unspecified).
3417  *              progname is just for use in error messages.
3418  *
3419  * Returns true on success; on failure, prints a suitable error message
3420  * to stderr and returns false.
3421  */
3422 bool
3423 SelectConfigFiles(const char *userDoption, const char *progname)
3424 {
3425         char       *configdir;
3426         char       *fname;
3427         struct stat stat_buf;
3428
3429         /* configdir is -D option, or $PGDATA if no -D */
3430         if (userDoption)
3431                 configdir = make_absolute_path(userDoption);
3432         else
3433                 configdir = make_absolute_path(getenv("PGDATA"));
3434
3435         /*
3436          * Find the configuration file: if config_file was specified on the
3437          * command line, use it, else use configdir/postgresql.conf.  In any case
3438          * ensure the result is an absolute path, so that it will be interpreted
3439          * the same way by future backends.
3440          */
3441         if (ConfigFileName)
3442                 fname = make_absolute_path(ConfigFileName);
3443         else if (configdir)
3444         {
3445                 fname = guc_malloc(FATAL,
3446                                                    strlen(configdir) + strlen(CONFIG_FILENAME) + 2);
3447                 sprintf(fname, "%s/%s", configdir, CONFIG_FILENAME);
3448         }
3449         else
3450         {
3451                 write_stderr("%s does not know where to find the server configuration file.\n"
3452                                          "You must specify the --config-file or -D invocation "
3453                                          "option or set the PGDATA environment variable.\n",
3454                                          progname);
3455                 return false;
3456         }
3457
3458         /*
3459          * Set the ConfigFileName GUC variable to its final value, ensuring that
3460          * it can't be overridden later.
3461          */
3462         SetConfigOption("config_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3463         free(fname);
3464
3465         /*
3466          * Now read the config file for the first time.
3467          */
3468         if (stat(ConfigFileName, &stat_buf) != 0)
3469         {
3470                 write_stderr("%s cannot access the server configuration file \"%s\": %s\n",
3471                                          progname, ConfigFileName, strerror(errno));
3472                 return false;
3473         }
3474
3475         ProcessConfigFile(PGC_POSTMASTER);
3476
3477         /*
3478          * If the data_directory GUC variable has been set, use that as DataDir;
3479          * otherwise use configdir if set; else punt.
3480          *
3481          * Note: SetDataDir will copy and absolute-ize its argument, so we don't
3482          * have to.
3483          */
3484         if (data_directory)
3485                 SetDataDir(data_directory);
3486         else if (configdir)
3487                 SetDataDir(configdir);
3488         else
3489         {
3490                 write_stderr("%s does not know where to find the database system data.\n"
3491                                          "This can be specified as \"data_directory\" in \"%s\", "
3492                                          "or by the -D invocation option, or by the "
3493                                          "PGDATA environment variable.\n",
3494                                          progname, ConfigFileName);
3495                 return false;
3496         }
3497
3498         /*
3499          * Reflect the final DataDir value back into the data_directory GUC var.
3500          * (If you are wondering why we don't just make them a single variable,
3501          * it's because the EXEC_BACKEND case needs DataDir to be transmitted to
3502          * child backends specially.  XXX is that still true?  Given that we now
3503          * chdir to DataDir, EXEC_BACKEND can read the config file without knowing
3504          * DataDir in advance.)
3505          */
3506         SetConfigOption("data_directory", DataDir, PGC_POSTMASTER, PGC_S_OVERRIDE);
3507
3508         /*
3509          * Figure out where pg_hba.conf is, and make sure the path is absolute.
3510          */
3511         if (HbaFileName)
3512                 fname = make_absolute_path(HbaFileName);
3513         else if (configdir)
3514         {
3515                 fname = guc_malloc(FATAL,
3516                                                    strlen(configdir) + strlen(HBA_FILENAME) + 2);
3517                 sprintf(fname, "%s/%s", configdir, HBA_FILENAME);
3518         }
3519         else
3520         {
3521                 write_stderr("%s does not know where to find the \"hba\" configuration file.\n"
3522                                          "This can be specified as \"hba_file\" in \"%s\", "
3523                                          "or by the -D invocation option, or by the "
3524                                          "PGDATA environment variable.\n",
3525                                          progname, ConfigFileName);
3526                 return false;
3527         }
3528         SetConfigOption("hba_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3529         free(fname);
3530
3531         /*
3532          * Likewise for pg_ident.conf.
3533          */
3534         if (IdentFileName)
3535                 fname = make_absolute_path(IdentFileName);
3536         else if (configdir)
3537         {
3538                 fname = guc_malloc(FATAL,
3539                                                    strlen(configdir) + strlen(IDENT_FILENAME) + 2);
3540                 sprintf(fname, "%s/%s", configdir, IDENT_FILENAME);
3541         }
3542         else
3543         {
3544                 write_stderr("%s does not know where to find the \"ident\" configuration file.\n"
3545                                          "This can be specified as \"ident_file\" in \"%s\", "
3546                                          "or by the -D invocation option, or by the "
3547                                          "PGDATA environment variable.\n",
3548                                          progname, ConfigFileName);
3549                 return false;
3550         }
3551         SetConfigOption("ident_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3552         free(fname);
3553
3554         free(configdir);
3555
3556         return true;
3557 }
3558
3559
3560 /*
3561  * Reset all options to their saved default values (implements RESET ALL)
3562  */
3563 void
3564 ResetAllOptions(void)
3565 {
3566         int                     i;
3567
3568         for (i = 0; i < num_guc_variables; i++)
3569         {
3570                 struct config_generic *gconf = guc_variables[i];
3571
3572                 /* Don't reset non-SET-able values */
3573                 if (gconf->context != PGC_SUSET &&
3574                         gconf->context != PGC_USERSET)
3575                         continue;
3576                 /* Don't reset if special exclusion from RESET ALL */
3577                 if (gconf->flags & GUC_NO_RESET_ALL)
3578                         continue;
3579                 /* No need to reset if wasn't SET */
3580                 if (gconf->source <= PGC_S_OVERRIDE)
3581                         continue;
3582
3583                 /* Save old value to support transaction abort */
3584                 push_old_value(gconf, GUC_ACTION_SET);
3585
3586                 switch (gconf->vartype)
3587                 {
3588                         case PGC_BOOL:
3589                                 {
3590                                         struct config_bool *conf = (struct config_bool *) gconf;
3591
3592                                         if (conf->assign_hook)
3593                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3594                                                                                                    PGC_S_SESSION))
3595                                                         elog(ERROR, "failed to reset %s to %d",
3596                                                                  conf->gen.name, (int) conf->reset_val);
3597                                         *conf->variable = conf->reset_val;
3598                                         break;
3599                                 }
3600                         case PGC_INT:
3601                                 {
3602                                         struct config_int *conf = (struct config_int *) gconf;
3603
3604                                         if (conf->assign_hook)
3605                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3606                                                                                                    PGC_S_SESSION))
3607                                                         elog(ERROR, "failed to reset %s to %d",
3608                                                                  conf->gen.name, conf->reset_val);
3609                                         *conf->variable = conf->reset_val;
3610                                         break;
3611                                 }
3612                         case PGC_REAL:
3613                                 {
3614                                         struct config_real *conf = (struct config_real *) gconf;
3615
3616                                         if (conf->assign_hook)
3617                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3618                                                                                                    PGC_S_SESSION))
3619                                                         elog(ERROR, "failed to reset %s to %g",
3620                                                                  conf->gen.name, conf->reset_val);
3621                                         *conf->variable = conf->reset_val;
3622                                         break;
3623                                 }
3624                         case PGC_STRING:
3625                                 {
3626                                         struct config_string *conf = (struct config_string *) gconf;
3627                                         char       *str;
3628
3629                                         /* We need not strdup here */
3630                                         str = conf->reset_val;
3631
3632                                         if (conf->assign_hook && str)
3633                                         {
3634                                                 const char *newstr;
3635
3636                                                 newstr = (*conf->assign_hook) (str, true,
3637                                                                                                            PGC_S_SESSION);
3638                                                 if (newstr == NULL)
3639                                                         elog(ERROR, "failed to reset %s to \"%s\"",
3640                                                                  conf->gen.name, str);
3641                                                 else if (newstr != str)
3642                                                 {
3643                                                         /*
3644                                                          * See notes in set_config_option about casting
3645                                                          */
3646                                                         str = (char *) newstr;
3647                                                 }
3648                                         }
3649
3650                                         set_string_field(conf, conf->variable, str);
3651                                         break;
3652                                 }
3653                         case PGC_ENUM:
3654                                 {
3655                                         struct config_enum *conf = (struct config_enum *) gconf;
3656
3657                                         if (conf->assign_hook)
3658                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3659                                                                                                    PGC_S_SESSION))
3660                                                         elog(ERROR, "failed to reset %s to %s",
3661                                                                  conf->gen.name,
3662                                                                  config_enum_lookup_by_value(conf, conf->reset_val));
3663                                         *conf->variable = conf->reset_val;
3664                                         break;
3665                                 }
3666                 }
3667
3668                 gconf->source = gconf->reset_source;
3669
3670                 if (gconf->flags & GUC_REPORT)
3671                         ReportGUCOption(gconf);
3672         }
3673 }
3674
3675
3676 /*
3677  * push_old_value
3678  *              Push previous state during transactional assignment to a GUC variable.
3679  */
3680 static void
3681 push_old_value(struct config_generic * gconf, GucAction action)
3682 {
3683         GucStack   *stack;
3684
3685         /* If we're not inside a nest level, do nothing */
3686         if (GUCNestLevel == 0)
3687                 return;
3688
3689         /* Do we already have a stack entry of the current nest level? */
3690         stack = gconf->stack;
3691         if (stack && stack->nest_level >= GUCNestLevel)
3692         {
3693                 /* Yes, so adjust its state if necessary */
3694                 Assert(stack->nest_level == GUCNestLevel);
3695                 switch (action)
3696                 {
3697                         case GUC_ACTION_SET:
3698                                 /* SET overrides any prior action at same nest level */
3699                                 if (stack->state == GUC_SET_LOCAL)
3700                                 {
3701                                         /* must discard old masked value */
3702                                         discard_stack_value(gconf, &stack->masked);
3703                                 }
3704                                 stack->state = GUC_SET;
3705                                 break;
3706                         case GUC_ACTION_LOCAL:
3707                                 if (stack->state == GUC_SET)
3708                                 {
3709                                         /* SET followed by SET LOCAL, remember SET's value */
3710                                         set_stack_value(gconf, &stack->masked);
3711                                         stack->state = GUC_SET_LOCAL;
3712                                 }
3713                                 /* in all other cases, no change to stack entry */
3714                                 break;
3715                         case GUC_ACTION_SAVE:
3716                                 /* Could only have a prior SAVE of same variable */
3717                                 Assert(stack->state == GUC_SAVE);
3718                                 break;
3719                 }
3720                 Assert(guc_dirty);              /* must be set already */
3721                 return;
3722         }
3723
3724         /*
3725          * Push a new stack entry
3726          *
3727          * We keep all the stack entries in TopTransactionContext for simplicity.
3728          */
3729         stack = (GucStack *) MemoryContextAllocZero(TopTransactionContext,
3730                                                                                                 sizeof(GucStack));
3731
3732         stack->prev = gconf->stack;
3733         stack->nest_level = GUCNestLevel;
3734         switch (action)
3735         {
3736                 case GUC_ACTION_SET:
3737                         stack->state = GUC_SET;
3738                         break;
3739                 case GUC_ACTION_LOCAL:
3740                         stack->state = GUC_LOCAL;
3741                         break;
3742                 case GUC_ACTION_SAVE:
3743                         stack->state = GUC_SAVE;
3744                         break;
3745         }
3746         stack->source = gconf->source;
3747         set_stack_value(gconf, &stack->prior);
3748
3749         gconf->stack = stack;
3750
3751         /* Ensure we remember to pop at end of xact */
3752         guc_dirty = true;
3753 }
3754
3755
3756 /*
3757  * Do GUC processing at main transaction start.
3758  */
3759 void
3760 AtStart_GUC(void)
3761 {
3762         /*
3763          * The nest level should be 0 between transactions; if it isn't, somebody
3764          * didn't call AtEOXact_GUC, or called it with the wrong nestLevel.  We
3765          * throw a warning but make no other effort to clean up.
3766          */
3767         if (GUCNestLevel != 0)
3768                 elog(WARNING, "GUC nest level = %d at transaction start",
3769                          GUCNestLevel);
3770         GUCNestLevel = 1;
3771 }
3772
3773 /*
3774  * Enter a new nesting level for GUC values.  This is called at subtransaction
3775  * start and when entering a function that has proconfig settings.      NOTE that
3776  * we must not risk error here, else subtransaction start will be unhappy.
3777  */
3778 int
3779 NewGUCNestLevel(void)
3780 {
3781         return ++GUCNestLevel;
3782 }
3783
3784 /*
3785  * Do GUC processing at transaction or subtransaction commit or abort, or
3786  * when exiting a function that has proconfig settings.  (The name is thus
3787  * a bit of a misnomer; perhaps it should be ExitGUCNestLevel or some such.)
3788  * During abort, we discard all GUC settings that were applied at nesting
3789  * levels >= nestLevel.  nestLevel == 1 corresponds to the main transaction.
3790  */
3791 void
3792 AtEOXact_GUC(bool isCommit, int nestLevel)
3793 {
3794         bool            still_dirty;
3795         int                     i;
3796
3797         Assert(nestLevel > 0 && nestLevel <= GUCNestLevel);
3798
3799         /* Quick exit if nothing's changed in this transaction */
3800         if (!guc_dirty)
3801         {
3802                 GUCNestLevel = nestLevel - 1;
3803                 return;
3804         }
3805
3806         still_dirty = false;
3807         for (i = 0; i < num_guc_variables; i++)
3808         {
3809                 struct config_generic *gconf = guc_variables[i];
3810                 GucStack   *stack;
3811
3812                 /*
3813                  * Process and pop each stack entry within the nest level.      To
3814                  * simplify fmgr_security_definer(), we allow failure exit from a
3815                  * function-with-SET-options to be recovered at the surrounding
3816                  * transaction or subtransaction abort; so there could be more than
3817                  * one stack entry to pop.
3818                  */
3819                 while ((stack = gconf->stack) != NULL &&
3820                            stack->nest_level >= nestLevel)
3821                 {
3822                         GucStack   *prev = stack->prev;
3823                         bool            restorePrior = false;
3824                         bool            restoreMasked = false;
3825                         bool            changed;
3826
3827                         /*
3828                          * In this next bit, if we don't set either restorePrior or
3829                          * restoreMasked, we must "discard" any unwanted fields of the
3830                          * stack entries to avoid leaking memory.  If we do set one of
3831                          * those flags, unused fields will be cleaned up after restoring.
3832                          */
3833                         if (!isCommit)          /* if abort, always restore prior value */
3834                                 restorePrior = true;
3835                         else if (stack->state == GUC_SAVE)
3836                                 restorePrior = true;
3837                         else if (stack->nest_level == 1)
3838                         {
3839                                 /* transaction commit */
3840                                 if (stack->state == GUC_SET_LOCAL)
3841                                         restoreMasked = true;
3842                                 else if (stack->state == GUC_SET)
3843                                 {
3844                                         /* we keep the current active value */
3845                                         discard_stack_value(gconf, &stack->prior);
3846                                 }
3847                                 else    /* must be GUC_LOCAL */
3848                                         restorePrior = true;
3849                         }
3850                         else if (prev == NULL ||
3851                                          prev->nest_level < stack->nest_level - 1)
3852                         {
3853                                 /* decrement entry's level and do not pop it */
3854                                 stack->nest_level--;
3855                                 continue;
3856                         }
3857                         else
3858                         {
3859                                 /*
3860                                  * We have to merge this stack entry into prev. See README for
3861                                  * discussion of this bit.
3862                                  */
3863                                 switch (stack->state)
3864                                 {
3865                                         case GUC_SAVE:
3866                                                 Assert(false);  /* can't get here */
3867
3868                                         case GUC_SET:
3869                                                 /* next level always becomes SET */
3870                                                 discard_stack_value(gconf, &stack->prior);
3871                                                 if (prev->state == GUC_SET_LOCAL)
3872                                                         discard_stack_value(gconf, &prev->masked);
3873                                                 prev->state = GUC_SET;
3874                                                 break;
3875
3876                                         case GUC_LOCAL:
3877                                                 if (prev->state == GUC_SET)
3878                                                 {
3879                                                         /* LOCAL migrates down */
3880                                                         prev->masked = stack->prior;
3881                                                         prev->state = GUC_SET_LOCAL;
3882                                                 }
3883                                                 else
3884                                                 {
3885                                                         /* else just forget this stack level */
3886                                                         discard_stack_value(gconf, &stack->prior);
3887                                                 }
3888                                                 break;
3889
3890                                         case GUC_SET_LOCAL:
3891                                                 /* prior state at this level no longer wanted */
3892                                                 discard_stack_value(gconf, &stack->prior);
3893                                                 /* copy down the masked state */
3894                                                 if (prev->state == GUC_SET_LOCAL)
3895                                                         discard_stack_value(gconf, &prev->masked);
3896                                                 prev->masked = stack->masked;
3897                                                 prev->state = GUC_SET_LOCAL;
3898                                                 break;
3899                                 }
3900                         }
3901
3902                         changed = false;
3903
3904                         if (restorePrior || restoreMasked)
3905                         {
3906                                 /* Perform appropriate restoration of the stacked value */
3907                                 union config_var_value newvalue;
3908                                 GucSource       newsource;
3909
3910                                 if (restoreMasked)
3911                                 {
3912                                         newvalue = stack->masked;
3913                                         newsource = PGC_S_SESSION;
3914                                 }
3915                                 else
3916                                 {
3917                                         newvalue = stack->prior;
3918                                         newsource = stack->source;
3919                                 }
3920
3921                                 switch (gconf->vartype)
3922                                 {
3923                                         case PGC_BOOL:
3924                                                 {
3925                                                         struct config_bool *conf = (struct config_bool *) gconf;
3926                                                         bool            newval = newvalue.boolval;
3927
3928                                                         if (*conf->variable != newval)
3929                                                         {
3930                                                                 if (conf->assign_hook)
3931                                                                         if (!(*conf->assign_hook) (newval,
3932                                                                                                            true, PGC_S_OVERRIDE))
3933                                                                                 elog(LOG, "failed to commit %s as %d",
3934                                                                                          conf->gen.name, (int) newval);
3935                                                                 *conf->variable = newval;
3936                                                                 changed = true;
3937                                                         }
3938                                                         break;
3939                                                 }
3940                                         case PGC_INT:
3941                                                 {
3942                                                         struct config_int *conf = (struct config_int *) gconf;
3943                                                         int                     newval = newvalue.intval;
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, newval);
3952                                                                 *conf->variable = newval;
3953                                                                 changed = true;
3954                                                         }
3955                                                         break;
3956                                                 }
3957                                         case PGC_REAL:
3958                                                 {
3959                                                         struct config_real *conf = (struct config_real *) gconf;
3960                                                         double          newval = newvalue.realval;
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 %g",
3968                                                                                          conf->gen.name, newval);
3969                                                                 *conf->variable = newval;
3970                                                                 changed = true;
3971                                                         }
3972                                                         break;
3973                                                 }
3974                                         case PGC_STRING:
3975                                                 {
3976                                                         struct config_string *conf = (struct config_string *) gconf;
3977                                                         char       *newval = newvalue.stringval;
3978
3979                                                         if (*conf->variable != newval)
3980                                                         {
3981                                                                 if (conf->assign_hook && newval)
3982                                                                 {
3983                                                                         const char *newstr;
3984
3985                                                                         newstr = (*conf->assign_hook) (newval, true,
3986                                                                                                                          PGC_S_OVERRIDE);
3987                                                                         if (newstr == NULL)
3988                                                                                 elog(LOG, "failed to commit %s as \"%s\"",
3989                                                                                          conf->gen.name, newval);
3990                                                                         else if (newstr != newval)
3991                                                                         {
3992                                                                                 /*
3993                                                                                  * If newval should now be freed,
3994                                                                                  * it'll be taken care of below.
3995                                                                                  *
3996                                                                                  * See notes in set_config_option
3997                                                                                  * about casting
3998                                                                                  */
3999                                                                                 newval = (char *) newstr;
4000                                                                         }
4001                                                                 }
4002
4003                                                                 set_string_field(conf, conf->variable, newval);
4004                                                                 changed = true;
4005                                                         }
4006
4007                                                         /*
4008                                                          * Release stacked values if not used anymore. We
4009                                                          * could use discard_stack_value() here, but since
4010                                                          * we have type-specific code anyway, might as
4011                                                          * well inline it.
4012                                                          */
4013                                                         set_string_field(conf, &stack->prior.stringval, NULL);
4014                                                         set_string_field(conf, &stack->masked.stringval, NULL);
4015                                                         break;
4016                                                 }
4017                                         case PGC_ENUM:
4018                                                 {
4019                                                         struct config_enum *conf = (struct config_enum *) gconf;
4020                                                         int                     newval = newvalue.enumval;
4021
4022                                                         if (*conf->variable != newval)
4023                                                         {
4024                                                                 if (conf->assign_hook)
4025                                                                         if (!(*conf->assign_hook) (newval,
4026                                                                                                            true, PGC_S_OVERRIDE))
4027                                                                                 elog(LOG, "failed to commit %s as %s",
4028                                                                                          conf->gen.name,
4029                                                                                          config_enum_lookup_by_value(conf, newval));
4030                                                                 *conf->variable = newval;
4031                                                                 changed = true;
4032                                                         }
4033                                                         break;
4034                                                 }
4035                                 }
4036
4037                                 gconf->source = newsource;
4038                         }
4039
4040                         /* Finish popping the state stack */
4041                         gconf->stack = prev;
4042                         pfree(stack);
4043
4044                         /* Report new value if we changed it */
4045                         if (changed && (gconf->flags & GUC_REPORT))
4046                                 ReportGUCOption(gconf);
4047                 }                                               /* end of stack-popping loop */
4048
4049                 if (stack != NULL)
4050                         still_dirty = true;
4051         }
4052
4053         /* If there are no remaining stack entries, we can reset guc_dirty */
4054         guc_dirty = still_dirty;
4055
4056         /* Update nesting level */
4057         GUCNestLevel = nestLevel - 1;
4058 }
4059
4060
4061 /*
4062  * Start up automatic reporting of changes to variables marked GUC_REPORT.
4063  * This is executed at completion of backend startup.
4064  */
4065 void
4066 BeginReportingGUCOptions(void)
4067 {
4068         int                     i;
4069
4070         /*
4071          * Don't do anything unless talking to an interactive frontend of protocol
4072          * 3.0 or later.
4073          */
4074         if (whereToSendOutput != DestRemote ||
4075                 PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
4076                 return;
4077
4078         reporting_enabled = true;
4079
4080         /* Transmit initial values of interesting variables */
4081         for (i = 0; i < num_guc_variables; i++)
4082         {
4083                 struct config_generic *conf = guc_variables[i];
4084
4085                 if (conf->flags & GUC_REPORT)
4086                         ReportGUCOption(conf);
4087         }
4088 }
4089
4090 /*
4091  * ReportGUCOption: if appropriate, transmit option value to frontend
4092  */
4093 static void
4094 ReportGUCOption(struct config_generic * record)
4095 {
4096         if (reporting_enabled && (record->flags & GUC_REPORT))
4097         {
4098                 char       *val = _ShowOption(record, false);
4099                 StringInfoData msgbuf;
4100
4101                 pq_beginmessage(&msgbuf, 'S');
4102                 pq_sendstring(&msgbuf, record->name);
4103                 pq_sendstring(&msgbuf, val);
4104                 pq_endmessage(&msgbuf);
4105
4106                 pfree(val);
4107         }
4108 }
4109
4110 /*
4111  * Try to parse value as an integer.  The accepted formats are the
4112  * usual decimal, octal, or hexadecimal formats, optionally followed by
4113  * a unit name if "flags" indicates a unit is allowed.
4114  *
4115  * If the string parses okay, return true, else false.
4116  * If okay and result is not NULL, return the value in *result.
4117  * If not okay and hintmsg is not NULL, *hintmsg is set to a suitable
4118  *      HINT message, or NULL if no hint provided.
4119  */
4120 bool
4121 parse_int(const char *value, int *result, int flags, const char **hintmsg)
4122 {
4123         int64           val;
4124         char       *endptr;
4125
4126         /* To suppress compiler warnings, always set output params */
4127         if (result)
4128                 *result = 0;
4129         if (hintmsg)
4130                 *hintmsg = NULL;
4131
4132         /* We assume here that int64 is at least as wide as long */
4133         errno = 0;
4134         val = strtol(value, &endptr, 0);
4135
4136         if (endptr == value)
4137                 return false;                   /* no HINT for integer syntax error */
4138
4139         if (errno == ERANGE || val != (int64) ((int32) val))
4140         {
4141                 if (hintmsg)
4142                         *hintmsg = gettext_noop("Value exceeds integer range.");
4143                 return false;
4144         }
4145
4146         /* allow whitespace between integer and unit */
4147         while (isspace((unsigned char) *endptr))
4148                 endptr++;
4149
4150         /* Handle possible unit */
4151         if (*endptr != '\0')
4152         {
4153                 /*
4154                  * Note: the multiple-switch coding technique here is a bit tedious,
4155                  * but seems necessary to avoid intermediate-value overflows.
4156                  *
4157                  * If INT64_IS_BUSTED (ie, it's really int32) we will fail to detect
4158                  * overflow due to units conversion, but there are few enough such
4159                  * machines that it does not seem worth trying to be smarter.
4160                  */
4161                 if (flags & GUC_UNIT_MEMORY)
4162                 {
4163                         /* Set hint for use if no match or trailing garbage */
4164                         if (hintmsg)
4165                                 *hintmsg = gettext_noop("Valid units for this parameter are \"kB\", \"MB\", and \"GB\".");
4166
4167 #if BLCKSZ < 1024 || BLCKSZ > (1024*1024)
4168 #error BLCKSZ must be between 1KB and 1MB
4169 #endif
4170 #if XLOG_BLCKSZ < 1024 || XLOG_BLCKSZ > (1024*1024)
4171 #error XLOG_BLCKSZ must be between 1KB and 1MB
4172 #endif
4173
4174                         if (strncmp(endptr, "kB", 2) == 0)
4175                         {
4176                                 endptr += 2;
4177                                 switch (flags & GUC_UNIT_MEMORY)
4178                                 {
4179                                         case GUC_UNIT_BLOCKS:
4180                                                 val /= (BLCKSZ / 1024);
4181                                                 break;
4182                                         case GUC_UNIT_XBLOCKS:
4183                                                 val /= (XLOG_BLCKSZ / 1024);
4184                                                 break;
4185                                 }
4186                         }
4187                         else if (strncmp(endptr, "MB", 2) == 0)
4188                         {
4189                                 endptr += 2;
4190                                 switch (flags & GUC_UNIT_MEMORY)
4191                                 {
4192                                         case GUC_UNIT_KB:
4193                                                 val *= KB_PER_MB;
4194                                                 break;
4195                                         case GUC_UNIT_BLOCKS:
4196                                                 val *= KB_PER_MB / (BLCKSZ / 1024);
4197                                                 break;
4198                                         case GUC_UNIT_XBLOCKS:
4199                                                 val *= KB_PER_MB / (XLOG_BLCKSZ / 1024);
4200                                                 break;
4201                                 }
4202                         }
4203                         else if (strncmp(endptr, "GB", 2) == 0)
4204                         {
4205                                 endptr += 2;
4206                                 switch (flags & GUC_UNIT_MEMORY)
4207                                 {
4208                                         case GUC_UNIT_KB:
4209                                                 val *= KB_PER_GB;
4210                                                 break;
4211                                         case GUC_UNIT_BLOCKS:
4212                                                 val *= KB_PER_GB / (BLCKSZ / 1024);
4213                                                 break;
4214                                         case GUC_UNIT_XBLOCKS:
4215                                                 val *= KB_PER_GB / (XLOG_BLCKSZ / 1024);
4216                                                 break;
4217                                 }
4218                         }
4219                 }
4220                 else if (flags & GUC_UNIT_TIME)
4221                 {
4222                         /* Set hint for use if no match or trailing garbage */
4223                         if (hintmsg)
4224                                 *hintmsg = gettext_noop("Valid units for this parameter are \"ms\", \"s\", \"min\", \"h\", and \"d\".");
4225
4226                         if (strncmp(endptr, "ms", 2) == 0)
4227                         {
4228                                 endptr += 2;
4229                                 switch (flags & GUC_UNIT_TIME)
4230                                 {
4231                                         case GUC_UNIT_S:
4232                                                 val /= MS_PER_S;
4233                                                 break;
4234                                         case GUC_UNIT_MIN:
4235                                                 val /= MS_PER_MIN;
4236                                                 break;
4237                                 }
4238                         }
4239                         else if (strncmp(endptr, "s", 1) == 0)
4240                         {
4241                                 endptr += 1;
4242                                 switch (flags & GUC_UNIT_TIME)
4243                                 {
4244                                         case GUC_UNIT_MS:
4245                                                 val *= MS_PER_S;
4246                                                 break;
4247                                         case GUC_UNIT_MIN:
4248                                                 val /= S_PER_MIN;
4249                                                 break;
4250                                 }
4251                         }
4252                         else if (strncmp(endptr, "min", 3) == 0)
4253                         {
4254                                 endptr += 3;
4255                                 switch (flags & GUC_UNIT_TIME)
4256                                 {
4257                                         case GUC_UNIT_MS:
4258                                                 val *= MS_PER_MIN;
4259                                                 break;
4260                                         case GUC_UNIT_S:
4261                                                 val *= S_PER_MIN;
4262                                                 break;
4263                                 }
4264                         }
4265                         else if (strncmp(endptr, "h", 1) == 0)
4266                         {
4267                                 endptr += 1;
4268                                 switch (flags & GUC_UNIT_TIME)
4269                                 {
4270                                         case GUC_UNIT_MS:
4271                                                 val *= MS_PER_H;
4272                                                 break;
4273                                         case GUC_UNIT_S:
4274                                                 val *= S_PER_H;
4275                                                 break;
4276                                         case GUC_UNIT_MIN:
4277                                                 val *= MIN_PER_H;
4278                                                 break;
4279                                 }
4280                         }
4281                         else if (strncmp(endptr, "d", 1) == 0)
4282                         {
4283                                 endptr += 1;
4284                                 switch (flags & GUC_UNIT_TIME)
4285                                 {
4286                                         case GUC_UNIT_MS:
4287                                                 val *= MS_PER_D;
4288                                                 break;
4289                                         case GUC_UNIT_S:
4290                                                 val *= S_PER_D;
4291                                                 break;
4292                                         case GUC_UNIT_MIN:
4293                                                 val *= MIN_PER_D;
4294                                                 break;
4295                                 }
4296                         }
4297                 }
4298
4299                 /* allow whitespace after unit */
4300                 while (isspace((unsigned char) *endptr))
4301                         endptr++;
4302
4303                 if (*endptr != '\0')
4304                         return false;           /* appropriate hint, if any, already set */
4305
4306                 /* Check for overflow due to units conversion */
4307                 if (val != (int64) ((int32) val))
4308                 {
4309                         if (hintmsg)
4310                                 *hintmsg = gettext_noop("Value exceeds integer range.");
4311                         return false;
4312                 }
4313         }
4314
4315         if (result)
4316                 *result = (int) val;
4317         return true;
4318 }
4319
4320
4321
4322 /*
4323  * Try to parse value as a floating point number in the usual format.
4324  * If the string parses okay, return true, else false.
4325  * If okay and result is not NULL, return the value in *result.
4326  */
4327 bool
4328 parse_real(const char *value, double *result)
4329 {
4330         double          val;
4331         char       *endptr;
4332
4333         if (result)
4334                 *result = 0;                    /* suppress compiler warning */
4335
4336         errno = 0;
4337         val = strtod(value, &endptr);
4338         if (endptr == value || errno == ERANGE)
4339                 return false;
4340
4341         /* allow whitespace after number */
4342         while (isspace((unsigned char) *endptr))
4343                 endptr++;
4344         if (*endptr != '\0')
4345                 return false;
4346
4347         if (result)
4348                 *result = val;
4349         return true;
4350 }
4351
4352
4353 /*
4354  * Lookup the name for an enum option with the selected value.
4355  * Should only ever be called with known-valid values, so throws
4356  * an elog(ERROR) if the enum option is not found.
4357  *
4358  * The returned string is a pointer to static data and not
4359  * allocated for modification.
4360  */
4361 const char *
4362 config_enum_lookup_by_value(struct config_enum * record, int val)
4363 {
4364         const struct config_enum_entry *entry;
4365
4366         for (entry = record->options; entry && entry->name; entry++)
4367         {
4368                 if (entry->val == val)
4369                         return entry->name;
4370         }
4371
4372         elog(ERROR, "could not find enum option %d for %s",
4373                  val, record->gen.name);
4374         return NULL;                            /* silence compiler */
4375 }
4376
4377
4378 /*
4379  * Lookup the value for an enum option with the selected name
4380  * (case-insensitive).
4381  * If the enum option is found, sets the retval value and returns
4382  * true. If it's not found, return FALSE and retval is set to 0.
4383  */
4384 bool
4385 config_enum_lookup_by_name(struct config_enum * record, const char *value,
4386                                                    int *retval)
4387 {
4388         const struct config_enum_entry *entry;
4389
4390         for (entry = record->options; entry && entry->name; entry++)
4391         {
4392                 if (pg_strcasecmp(value, entry->name) == 0)
4393                 {
4394                         *retval = entry->val;
4395                         return TRUE;
4396                 }
4397         }
4398
4399         *retval = 0;
4400         return FALSE;
4401 }
4402
4403
4404 /*
4405  * Return a list of all available options for an enum, excluding
4406  * hidden ones, separated by the given separator.
4407  * If prefix is non-NULL, it is added before the first enum value.
4408  * If suffix is non-NULL, it is added to the end of the string.
4409  */
4410 static char *
4411 config_enum_get_options(struct config_enum * record, const char *prefix,
4412                                                 const char *suffix, const char *separator)
4413 {
4414         const struct config_enum_entry *entry;
4415         StringInfoData retstr;
4416         int                     seplen;
4417
4418         initStringInfo(&retstr);
4419         appendStringInfoString(&retstr, prefix);
4420
4421         seplen = strlen(separator);
4422         for (entry = record->options; entry && entry->name; entry++)
4423         {
4424                 if (!entry->hidden)
4425                 {
4426                         appendStringInfoString(&retstr, entry->name);
4427                         appendBinaryStringInfo(&retstr, separator, seplen);
4428                 }
4429         }
4430
4431         /*
4432          * All the entries may have been hidden, leaving the string empty if no
4433          * prefix was given. This indicates a broken GUC setup, since there is no
4434          * use for an enum without any values, so we just check to make sure we
4435          * don't write to invalid memory instead of actually trying to do
4436          * something smart with it.
4437          */
4438         if (retstr.len >= seplen)
4439         {
4440                 /* Replace final separator */
4441                 retstr.data[retstr.len - seplen] = '\0';
4442                 retstr.len -= seplen;
4443         }
4444
4445         appendStringInfoString(&retstr, suffix);
4446
4447         return retstr.data;
4448 }
4449
4450 /*
4451  * Call a GucStringAssignHook function, being careful to free the
4452  * "newval" string if the hook ereports.
4453  *
4454  * This is split out of set_config_option just to avoid the "volatile"
4455  * qualifiers that would otherwise have to be plastered all over.
4456  */
4457 static const char *
4458 call_string_assign_hook(GucStringAssignHook assign_hook,
4459                                                 char *newval, bool doit, GucSource source)
4460 {
4461         const char *result;
4462
4463         PG_TRY();
4464         {
4465                 result = (*assign_hook) (newval, doit, source);
4466         }
4467         PG_CATCH();
4468         {
4469                 free(newval);
4470                 PG_RE_THROW();
4471         }
4472         PG_END_TRY();
4473
4474         return result;
4475 }
4476
4477
4478 /*
4479  * Sets option `name' to given value. The value should be a string
4480  * which is going to be parsed and converted to the appropriate data
4481  * type.  The context and source parameters indicate in which context this
4482  * function is being called so it can apply the access restrictions
4483  * properly.
4484  *
4485  * If value is NULL, set the option to its default value (normally the
4486  * reset_val, but if source == PGC_S_DEFAULT we instead use the boot_val).
4487  *
4488  * action indicates whether to set the value globally in the session, locally
4489  * to the current top transaction, or just for the duration of a function call.
4490  *
4491  * If changeVal is false then don't really set the option but do all
4492  * the checks to see if it would work.
4493  *
4494  * If there is an error (non-existing option, invalid value) then an
4495  * ereport(ERROR) is thrown *unless* this is called in a context where we
4496  * don't want to ereport (currently, startup or SIGHUP config file reread).
4497  * In that case we write a suitable error message via ereport(LOG) and
4498  * return false. This is working around the deficiencies in the ereport
4499  * mechanism, so don't blame me.  In all other cases, the function
4500  * returns true, including cases where the input is valid but we chose
4501  * not to apply it because of context or source-priority considerations.
4502  *
4503  * See also SetConfigOption for an external interface.
4504  */
4505 bool
4506 set_config_option(const char *name, const char *value,
4507                                   GucContext context, GucSource source,
4508                                   GucAction action, bool changeVal)
4509 {
4510         struct config_generic *record;
4511         int                     elevel;
4512         bool            makeDefault;
4513
4514         if (context == PGC_SIGHUP || source == PGC_S_DEFAULT)
4515         {
4516                 /*
4517                  * To avoid cluttering the log, only the postmaster bleats loudly
4518                  * about problems with the config file.
4519                  */
4520                 elevel = IsUnderPostmaster ? DEBUG3 : LOG;
4521         }
4522         else if (source == PGC_S_DATABASE || source == PGC_S_USER)
4523                 elevel = WARNING;
4524         else
4525                 elevel = ERROR;
4526
4527         record = find_option(name, true, elevel);
4528         if (record == NULL)
4529         {
4530                 ereport(elevel,
4531                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
4532                            errmsg("unrecognized configuration parameter \"%s\"", name)));
4533                 return false;
4534         }
4535
4536         /*
4537          * If source is postgresql.conf, mark the found record with
4538          * GUC_IS_IN_FILE. This is for the convenience of ProcessConfigFile.  Note
4539          * that we do it even if changeVal is false, since ProcessConfigFile wants
4540          * the marking to occur during its testing pass.
4541          */
4542         if (source == PGC_S_FILE)
4543                 record->status |= GUC_IS_IN_FILE;
4544
4545         /*
4546          * Check if the option can be set at this time. See guc.h for the precise
4547          * rules. Note that we don't want to throw errors if we're in the SIGHUP
4548          * context. In that case we just ignore the attempt and return true.
4549          */
4550         switch (record->context)
4551         {
4552                 case PGC_INTERNAL:
4553                         if (context == PGC_SIGHUP)
4554                                 return true;
4555                         if (context != PGC_INTERNAL)
4556                         {
4557                                 ereport(elevel,
4558                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4559                                                  errmsg("parameter \"%s\" cannot be changed",
4560                                                                 name)));
4561                                 return false;
4562                         }
4563                         break;
4564                 case PGC_POSTMASTER:
4565                         if (context == PGC_SIGHUP)
4566                         {
4567                                 /*
4568                                  * We are reading a PGC_POSTMASTER var from postgresql.conf.
4569                                  * We can't change the setting, so give a warning if the DBA
4570                                  * tries to change it.  (Throwing an error would be more
4571                                  * consistent, but seems overly rigid.)
4572                                  */
4573                                 if (changeVal && !is_newvalue_equal(record, value))
4574                                         ereport(elevel,
4575                                                         (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4576                                            errmsg("attempted change of parameter \"%s\" ignored",
4577                                                           name),
4578                                                          errdetail("This parameter cannot be changed after server start.")));
4579                                 return true;
4580                         }
4581                         if (context != PGC_POSTMASTER)
4582                         {
4583                                 ereport(elevel,
4584                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4585                                            errmsg("attempted change of parameter \"%s\" ignored",
4586                                                           name),
4587                                                  errdetail("This parameter cannot be changed after server start.")));
4588                                 return false;
4589                         }
4590                         break;
4591                 case PGC_SIGHUP:
4592                         if (context != PGC_SIGHUP && context != PGC_POSTMASTER)
4593                         {
4594                                 ereport(elevel,
4595                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4596                                                  errmsg("parameter \"%s\" cannot be changed now",
4597                                                                 name)));
4598                                 return false;
4599                         }
4600
4601                         /*
4602                          * Hmm, the idea of the SIGHUP context is "ought to be global, but
4603                          * can be changed after postmaster start". But there's nothing
4604                          * that prevents a crafty administrator from sending SIGHUP
4605                          * signals to individual backends only.
4606                          */
4607                         break;
4608                 case PGC_BACKEND:
4609                         if (context == PGC_SIGHUP)
4610                         {
4611                                 /*
4612                                  * If a PGC_BACKEND parameter is changed in the config file,
4613                                  * we want to accept the new value in the postmaster (whence
4614                                  * it will propagate to subsequently-started backends), but
4615                                  * ignore it in existing backends.      This is a tad klugy, but
4616                                  * necessary because we don't re-read the config file during
4617                                  * backend start.
4618                                  */
4619                                 if (IsUnderPostmaster)
4620                                         return true;
4621                         }
4622                         else if (context != PGC_BACKEND && context != PGC_POSTMASTER)
4623                         {
4624                                 ereport(elevel,
4625                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4626                                                  errmsg("parameter \"%s\" cannot be set after connection start",
4627                                                                 name)));
4628                                 return false;
4629                         }
4630                         break;
4631                 case PGC_SUSET:
4632                         if (context == PGC_USERSET || context == PGC_BACKEND)
4633                         {
4634                                 ereport(elevel,
4635                                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
4636                                                  errmsg("permission denied to set parameter \"%s\"",
4637                                                                 name)));
4638                                 return false;
4639                         }
4640                         break;
4641                 case PGC_USERSET:
4642                         /* always okay */
4643                         break;
4644         }
4645
4646         /*
4647          * Should we set reset/stacked values?  (If so, the behavior is not
4648          * transactional.)      This is done either when we get a default value from
4649          * the database's/user's/client's default settings or when we reset a
4650          * value to its default.
4651          */
4652         makeDefault = changeVal && (source <= PGC_S_OVERRIDE) &&
4653                 ((value != NULL) || source == PGC_S_DEFAULT);
4654
4655         /*
4656          * Ignore attempted set if overridden by previously processed setting.
4657          * However, if changeVal is false then plow ahead anyway since we are
4658          * trying to find out if the value is potentially good, not actually use
4659          * it. Also keep going if makeDefault is true, since we may want to set
4660          * the reset/stacked values even if we can't set the variable itself.
4661          */
4662         if (record->source > source)
4663         {
4664                 if (changeVal && !makeDefault)
4665                 {
4666                         elog(DEBUG3, "\"%s\": setting ignored because previous source is higher priority",
4667                                  name);
4668                         return true;
4669                 }
4670                 changeVal = false;
4671         }
4672
4673         /*
4674          * Evaluate value and set variable.
4675          */
4676         switch (record->vartype)
4677         {
4678                 case PGC_BOOL:
4679                         {
4680                                 struct config_bool *conf = (struct config_bool *) record;
4681                                 bool            newval;
4682
4683                                 if (value)
4684                                 {
4685                                         if (!parse_bool(value, &newval))
4686                                         {
4687                                                 ereport(elevel,
4688                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4689                                                   errmsg("parameter \"%s\" requires a Boolean value",
4690                                                                  name)));
4691                                                 return false;
4692                                         }
4693                                 }
4694                                 else if (source == PGC_S_DEFAULT)
4695                                         newval = conf->boot_val;
4696                                 else
4697                                 {
4698                                         newval = conf->reset_val;
4699                                         source = conf->gen.reset_source;
4700                                 }
4701
4702                                 /* Save old value to support transaction abort */
4703                                 if (changeVal && !makeDefault)
4704                                         push_old_value(&conf->gen, action);
4705
4706                                 if (conf->assign_hook)
4707                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4708                                         {
4709                                                 ereport(elevel,
4710                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4711                                                          errmsg("invalid value for parameter \"%s\": %d",
4712                                                                         name, (int) newval)));
4713                                                 return false;
4714                                         }
4715
4716                                 if (changeVal)
4717                                 {
4718                                         *conf->variable = newval;
4719                                         conf->gen.source = source;
4720                                 }
4721                                 if (makeDefault)
4722                                 {
4723                                         GucStack   *stack;
4724
4725                                         if (conf->gen.reset_source <= source)
4726                                         {
4727                                                 conf->reset_val = newval;
4728                                                 conf->gen.reset_source = source;
4729                                         }
4730                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4731                                         {
4732                                                 if (stack->source <= source)
4733                                                 {
4734                                                         stack->prior.boolval = newval;
4735                                                         stack->source = source;
4736                                                 }
4737                                         }
4738                                 }
4739                                 break;
4740                         }
4741
4742                 case PGC_INT:
4743                         {
4744                                 struct config_int *conf = (struct config_int *) record;
4745                                 int                     newval;
4746
4747                                 if (value)
4748                                 {
4749                                         const char *hintmsg;
4750
4751                                         if (!parse_int(value, &newval, conf->gen.flags, &hintmsg))
4752                                         {
4753                                                 ereport(elevel,
4754                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4755                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
4756                                                                 name, value),
4757                                                                  hintmsg ? errhint("%s", _(hintmsg)) : 0));
4758                                                 return false;
4759                                         }
4760                                         if (newval < conf->min || newval > conf->max)
4761                                         {
4762                                                 ereport(elevel,
4763                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4764                                                                  errmsg("%d is outside the valid range for parameter \"%s\" (%d .. %d)",
4765                                                                                 newval, name, conf->min, conf->max)));
4766                                                 return false;
4767                                         }
4768                                 }
4769                                 else if (source == PGC_S_DEFAULT)
4770                                         newval = conf->boot_val;
4771                                 else
4772                                 {
4773                                         newval = conf->reset_val;
4774                                         source = conf->gen.reset_source;
4775                                 }
4776
4777                                 /* Save old value to support transaction abort */
4778                                 if (changeVal && !makeDefault)
4779                                         push_old_value(&conf->gen, action);
4780
4781                                 if (conf->assign_hook)
4782                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4783                                         {
4784                                                 ereport(elevel,
4785                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4786                                                          errmsg("invalid value for parameter \"%s\": %d",
4787                                                                         name, newval)));
4788                                                 return false;
4789                                         }
4790
4791                                 if (changeVal)
4792                                 {
4793                                         *conf->variable = newval;
4794                                         conf->gen.source = source;
4795                                 }
4796                                 if (makeDefault)
4797                                 {
4798                                         GucStack   *stack;
4799
4800                                         if (conf->gen.reset_source <= source)
4801                                         {
4802                                                 conf->reset_val = newval;
4803                                                 conf->gen.reset_source = source;
4804                                         }
4805                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4806                                         {
4807                                                 if (stack->source <= source)
4808                                                 {
4809                                                         stack->prior.intval = newval;
4810                                                         stack->source = source;
4811                                                 }
4812                                         }
4813                                 }
4814                                 break;
4815                         }
4816
4817                 case PGC_REAL:
4818                         {
4819                                 struct config_real *conf = (struct config_real *) record;
4820                                 double          newval;
4821
4822                                 if (value)
4823                                 {
4824                                         if (!parse_real(value, &newval))
4825                                         {
4826                                                 ereport(elevel,
4827                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4828                                                   errmsg("parameter \"%s\" requires a numeric value",
4829                                                                  name)));
4830                                                 return false;
4831                                         }
4832                                         if (newval < conf->min || newval > conf->max)
4833                                         {
4834                                                 ereport(elevel,
4835                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4836                                                                  errmsg("%g is outside the valid range for parameter \"%s\" (%g .. %g)",
4837                                                                                 newval, name, conf->min, conf->max)));
4838                                                 return false;
4839                                         }
4840                                 }
4841                                 else if (source == PGC_S_DEFAULT)
4842                                         newval = conf->boot_val;
4843                                 else
4844                                 {
4845                                         newval = conf->reset_val;
4846                                         source = conf->gen.reset_source;
4847                                 }
4848
4849                                 /* Save old value to support transaction abort */
4850                                 if (changeVal && !makeDefault)
4851                                         push_old_value(&conf->gen, action);
4852
4853                                 if (conf->assign_hook)
4854                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4855                                         {
4856                                                 ereport(elevel,
4857                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4858                                                          errmsg("invalid value for parameter \"%s\": %g",
4859                                                                         name, newval)));
4860                                                 return false;
4861                                         }
4862
4863                                 if (changeVal)
4864                                 {
4865                                         *conf->variable = newval;
4866                                         conf->gen.source = source;
4867                                 }
4868                                 if (makeDefault)
4869                                 {
4870                                         GucStack   *stack;
4871
4872                                         if (conf->gen.reset_source <= source)
4873                                         {
4874                                                 conf->reset_val = newval;
4875                                                 conf->gen.reset_source = source;
4876                                         }
4877                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4878                                         {
4879                                                 if (stack->source <= source)
4880                                                 {
4881                                                         stack->prior.realval = newval;
4882                                                         stack->source = source;
4883                                                 }
4884                                         }
4885                                 }
4886                                 break;
4887                         }
4888
4889                 case PGC_STRING:
4890                         {
4891                                 struct config_string *conf = (struct config_string *) record;
4892                                 char       *newval;
4893
4894                                 if (value)
4895                                 {
4896                                         newval = guc_strdup(elevel, value);
4897                                         if (newval == NULL)
4898                                                 return false;
4899
4900                                         /*
4901                                          * The only sort of "parsing" check we need to do is apply
4902                                          * truncation if GUC_IS_NAME.
4903                                          */
4904                                         if (conf->gen.flags & GUC_IS_NAME)
4905                                                 truncate_identifier(newval, strlen(newval), true);
4906                                 }
4907                                 else if (source == PGC_S_DEFAULT)
4908                                 {
4909                                         if (conf->boot_val == NULL)
4910                                                 newval = NULL;
4911                                         else
4912                                         {
4913                                                 newval = guc_strdup(elevel, conf->boot_val);
4914                                                 if (newval == NULL)
4915                                                         return false;
4916                                         }
4917                                 }
4918                                 else
4919                                 {
4920                                         /*
4921                                          * We could possibly avoid strdup here, but easier to make
4922                                          * this case work the same as the normal assignment case;
4923                                          * note the possible free of newval below.
4924                                          */
4925                                         if (conf->reset_val == NULL)
4926                                                 newval = NULL;
4927                                         else
4928                                         {
4929                                                 newval = guc_strdup(elevel, conf->reset_val);
4930                                                 if (newval == NULL)
4931                                                         return false;
4932                                         }
4933                                         source = conf->gen.reset_source;
4934                                 }
4935
4936                                 /* Save old value to support transaction abort */
4937                                 if (changeVal && !makeDefault)
4938                                         push_old_value(&conf->gen, action);
4939
4940                                 if (conf->assign_hook && newval)
4941                                 {
4942                                         const char *hookresult;
4943
4944                                         /*
4945                                          * If the hook ereports, we have to make sure we free
4946                                          * newval, else it will be a permanent memory leak.
4947                                          */
4948                                         hookresult = call_string_assign_hook(conf->assign_hook,
4949                                                                                                                  newval,
4950                                                                                                                  changeVal,
4951                                                                                                                  source);
4952                                         if (hookresult == NULL)
4953                                         {
4954                                                 free(newval);
4955                                                 ereport(elevel,
4956                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4957                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
4958                                                                 name, value ? value : "")));
4959                                                 return false;
4960                                         }
4961                                         else if (hookresult != newval)
4962                                         {
4963                                                 free(newval);
4964
4965                                                 /*
4966                                                  * Having to cast away const here is annoying, but the
4967                                                  * alternative is to declare assign_hooks as returning
4968                                                  * char*, which would mean they'd have to cast away
4969                                                  * const, or as both taking and returning char*, which
4970                                                  * doesn't seem attractive either --- we don't want
4971                                                  * them to scribble on the passed str.
4972                                                  */
4973                                                 newval = (char *) hookresult;
4974                                         }
4975                                 }
4976
4977                                 if (changeVal)
4978                                 {
4979                                         set_string_field(conf, conf->variable, newval);
4980                                         conf->gen.source = source;
4981                                 }
4982                                 if (makeDefault)
4983                                 {
4984                                         GucStack   *stack;
4985
4986                                         if (conf->gen.reset_source <= source)
4987                                         {
4988                                                 set_string_field(conf, &conf->reset_val, newval);
4989                                                 conf->gen.reset_source = source;
4990                                         }
4991                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4992                                         {
4993                                                 if (stack->source <= source)
4994                                                 {
4995                                                         set_string_field(conf, &stack->prior.stringval,
4996                                                                                          newval);
4997                                                         stack->source = source;
4998                                                 }
4999                                         }
5000                                 }
5001                                 /* Perhaps we didn't install newval anywhere */
5002                                 if (newval && !string_field_used(conf, newval))
5003                                         free(newval);
5004                                 break;
5005                         }
5006                 case PGC_ENUM:
5007                         {
5008                                 struct config_enum *conf = (struct config_enum *) record;
5009                                 int                     newval;
5010
5011                                 if (value)
5012                                 {
5013                                         if (!config_enum_lookup_by_name(conf, value, &newval))
5014                                         {
5015                                                 char       *hintmsg;
5016
5017                                                 hintmsg = config_enum_get_options(conf,
5018                                                                                                                 "Available values: ",
5019                                                                                                                   ".", ", ");
5020
5021                                                 ereport(elevel,
5022                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5023                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
5024                                                                 name, value),
5025                                                                  hintmsg ? errhint("%s", _(hintmsg)) : 0));
5026
5027                                                 if (hintmsg)
5028                                                         pfree(hintmsg);
5029                                                 return false;
5030                                         }
5031                                 }
5032                                 else if (source == PGC_S_DEFAULT)
5033                                         newval = conf->boot_val;
5034                                 else
5035                                 {
5036                                         newval = conf->reset_val;
5037                                         source = conf->gen.reset_source;
5038                                 }
5039
5040                                 /* Save old value to support transaction abort */
5041                                 if (changeVal && !makeDefault)
5042                                         push_old_value(&conf->gen, action);
5043
5044                                 if (conf->assign_hook)
5045                                         if (!(*conf->assign_hook) (newval, changeVal, source))
5046                                         {
5047                                                 ereport(elevel,
5048                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5049                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
5050                                                                 name,
5051                                                                 config_enum_lookup_by_value(conf, newval))));
5052                                                 return false;
5053                                         }
5054
5055                                 if (changeVal)
5056                                 {
5057                                         *conf->variable = newval;
5058                                         conf->gen.source = source;
5059                                 }
5060                                 if (makeDefault)
5061                                 {
5062                                         GucStack   *stack;
5063
5064                                         if (conf->gen.reset_source <= source)
5065                                         {
5066                                                 conf->reset_val = newval;
5067                                                 conf->gen.reset_source = source;
5068                                         }
5069                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
5070                                         {
5071                                                 if (stack->source <= source)
5072                                                 {
5073                                                         stack->prior.enumval = newval;
5074                                                         stack->source = source;
5075                                                 }
5076                                         }
5077                                 }
5078                                 break;
5079                         }
5080         }
5081
5082         if (changeVal && (record->flags & GUC_REPORT))
5083                 ReportGUCOption(record);
5084
5085         return true;
5086 }
5087
5088
5089 /*
5090  * Set the fields for source file and line number the setting came from.
5091  */
5092 static void
5093 set_config_sourcefile(const char *name, char *sourcefile, int sourceline)
5094 {
5095         struct config_generic *record;
5096         int                     elevel;
5097
5098         /*
5099          * To avoid cluttering the log, only the postmaster bleats loudly about
5100          * problems with the config file.
5101          */
5102         elevel = IsUnderPostmaster ? DEBUG3 : LOG;
5103
5104         record = find_option(name, true, elevel);
5105         /* should not happen */
5106         if (record == NULL)
5107                 elog(ERROR, "unrecognized configuration parameter \"%s\"", name);
5108
5109         sourcefile = guc_strdup(elevel, sourcefile);
5110         if (record->sourcefile)
5111                 free(record->sourcefile);
5112         record->sourcefile = sourcefile;
5113         record->sourceline = sourceline;
5114 }
5115
5116 /*
5117  * Set a config option to the given value. See also set_config_option,
5118  * this is just the wrapper to be called from outside GUC.      NB: this
5119  * is used only for non-transactional operations.
5120  *
5121  * Note: there is no support here for setting source file/line, as it
5122  * is currently not needed.
5123  */
5124 void
5125 SetConfigOption(const char *name, const char *value,
5126                                 GucContext context, GucSource source)
5127 {
5128         (void) set_config_option(name, value, context, source,
5129                                                          GUC_ACTION_SET, true);
5130 }
5131
5132
5133
5134 /*
5135  * Fetch the current value of the option `name'. If the option doesn't exist,
5136  * throw an ereport and don't return.
5137  *
5138  * The string is *not* allocated for modification and is really only
5139  * valid until the next call to configuration related functions.
5140  */
5141 const char *
5142 GetConfigOption(const char *name)
5143 {
5144         struct config_generic *record;
5145         static char buffer[256];
5146
5147         record = find_option(name, false, ERROR);
5148         if (record == NULL)
5149                 ereport(ERROR,
5150                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5151                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5152         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
5153                 ereport(ERROR,
5154                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5155                                  errmsg("must be superuser to examine \"%s\"", name)));
5156
5157         switch (record->vartype)
5158         {
5159                 case PGC_BOOL:
5160                         return *((struct config_bool *) record)->variable ? "on" : "off";
5161
5162                 case PGC_INT:
5163                         snprintf(buffer, sizeof(buffer), "%d",
5164                                          *((struct config_int *) record)->variable);
5165                         return buffer;
5166
5167                 case PGC_REAL:
5168                         snprintf(buffer, sizeof(buffer), "%g",
5169                                          *((struct config_real *) record)->variable);
5170                         return buffer;
5171
5172                 case PGC_STRING:
5173                         return *((struct config_string *) record)->variable;
5174
5175                 case PGC_ENUM:
5176                         return config_enum_lookup_by_value((struct config_enum *) record,
5177                                                                  *((struct config_enum *) record)->variable);
5178         }
5179         return NULL;
5180 }
5181
5182 /*
5183  * Get the RESET value associated with the given option.
5184  *
5185  * Note: this is not re-entrant, due to use of static result buffer;
5186  * not to mention that a string variable could have its reset_val changed.
5187  * Beware of assuming the result value is good for very long.
5188  */
5189 const char *
5190 GetConfigOptionResetString(const char *name)
5191 {
5192         struct config_generic *record;
5193         static char buffer[256];
5194
5195         record = find_option(name, false, ERROR);
5196         if (record == NULL)
5197                 ereport(ERROR,
5198                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5199                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5200         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
5201                 ereport(ERROR,
5202                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5203                                  errmsg("must be superuser to examine \"%s\"", name)));
5204
5205         switch (record->vartype)
5206         {
5207                 case PGC_BOOL:
5208                         return ((struct config_bool *) record)->reset_val ? "on" : "off";
5209
5210                 case PGC_INT:
5211                         snprintf(buffer, sizeof(buffer), "%d",
5212                                          ((struct config_int *) record)->reset_val);
5213                         return buffer;
5214
5215                 case PGC_REAL:
5216                         snprintf(buffer, sizeof(buffer), "%g",
5217                                          ((struct config_real *) record)->reset_val);
5218                         return buffer;
5219
5220                 case PGC_STRING:
5221                         return ((struct config_string *) record)->reset_val;
5222
5223                 case PGC_ENUM:
5224                         return config_enum_lookup_by_value((struct config_enum *) record,
5225                                                                  ((struct config_enum *) record)->reset_val);
5226         }
5227         return NULL;
5228 }
5229
5230 /*
5231  * Detect whether the given configuration option can only be set by
5232  * a superuser.
5233  */
5234 bool
5235 IsSuperuserConfigOption(const char *name)
5236 {
5237         struct config_generic *record;
5238
5239         record = find_option(name, false, ERROR);
5240         /* On an unrecognized name, don't error, just return false. */
5241         if (record == NULL)
5242                 return false;
5243         return (record->context == PGC_SUSET);
5244 }
5245
5246
5247 /*
5248  * GUC_complaint_elevel
5249  *              Get the ereport error level to use in an assign_hook's error report.
5250  *
5251  * This should be used by assign hooks that want to emit a custom error
5252  * report (in addition to the generic "invalid value for option FOO" that
5253  * guc.c will provide).  Note that the result might be ERROR or a lower
5254  * level, so the caller must be prepared for control to return from ereport,
5255  * or not.      If control does return, return false/NULL from the hook function.
5256  *
5257  * At some point it'd be nice to replace this with a mechanism that allows
5258  * the custom message to become the DETAIL line of guc.c's generic message.
5259  */
5260 int
5261 GUC_complaint_elevel(GucSource source)
5262 {
5263         int                     elevel;
5264
5265         if (source == PGC_S_FILE)
5266         {
5267                 /*
5268                  * To avoid cluttering the log, only the postmaster bleats loudly
5269                  * about problems with the config file.
5270                  */
5271                 elevel = IsUnderPostmaster ? DEBUG3 : LOG;
5272         }
5273         else if (source == PGC_S_OVERRIDE)
5274         {
5275                 /*
5276                  * If we're a postmaster child, this is probably "undo" during
5277                  * transaction abort, so we don't want to clutter the log.  There's a
5278                  * small chance of a real problem with an OVERRIDE setting, though, so
5279                  * suppressing the message entirely wouldn't be desirable.
5280                  */
5281                 elevel = IsUnderPostmaster ? DEBUG5 : LOG;
5282         }
5283         else if (source < PGC_S_INTERACTIVE)
5284                 elevel = LOG;
5285         else
5286                 elevel = ERROR;
5287
5288         return elevel;
5289 }
5290
5291
5292 /*
5293  * flatten_set_variable_args
5294  *              Given a parsenode List as emitted by the grammar for SET,
5295  *              convert to the flat string representation used by GUC.
5296  *
5297  * We need to be told the name of the variable the args are for, because
5298  * the flattening rules vary (ugh).
5299  *
5300  * The result is NULL if args is NIL (ie, SET ... TO DEFAULT), otherwise
5301  * a palloc'd string.
5302  */
5303 static char *
5304 flatten_set_variable_args(const char *name, List *args)
5305 {
5306         struct config_generic *record;
5307         int                     flags;
5308         StringInfoData buf;
5309         ListCell   *l;
5310
5311         /* Fast path if just DEFAULT */
5312         if (args == NIL)
5313                 return NULL;
5314
5315         /* Else get flags for the variable */
5316         record = find_option(name, true, ERROR);
5317         if (record == NULL)
5318                 ereport(ERROR,
5319                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5320                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5321
5322         flags = record->flags;
5323
5324         /* Complain if list input and non-list variable */
5325         if ((flags & GUC_LIST_INPUT) == 0 &&
5326                 list_length(args) != 1)
5327                 ereport(ERROR,
5328                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5329                                  errmsg("SET %s takes only one argument", name)));
5330
5331         initStringInfo(&buf);
5332
5333         /*
5334          * Each list member may be a plain A_Const node, or an A_Const within a
5335          * TypeCast; the latter case is supported only for ConstInterval arguments
5336          * (for SET TIME ZONE).
5337          */
5338         foreach(l, args)
5339         {
5340                 Node       *arg = (Node *) lfirst(l);
5341                 char       *val;
5342                 TypeName   *typeName = NULL;
5343                 A_Const    *con;
5344
5345                 if (l != list_head(args))
5346                         appendStringInfo(&buf, ", ");
5347
5348                 if (IsA(arg, TypeCast))
5349                 {
5350                         TypeCast   *tc = (TypeCast *) arg;
5351
5352                         arg = tc->arg;
5353                         typeName = tc->typeName;
5354                 }
5355
5356                 if (!IsA(arg, A_Const))
5357                         elog(ERROR, "unrecognized node type: %d", (int) nodeTag(arg));
5358                 con = (A_Const *) arg;
5359
5360                 switch (nodeTag(&con->val))
5361                 {
5362                         case T_Integer:
5363                                 appendStringInfo(&buf, "%ld", intVal(&con->val));
5364                                 break;
5365                         case T_Float:
5366                                 /* represented as a string, so just copy it */
5367                                 appendStringInfoString(&buf, strVal(&con->val));
5368                                 break;
5369                         case T_String:
5370                                 val = strVal(&con->val);
5371                                 if (typeName != NULL)
5372                                 {
5373                                         /*
5374                                          * Must be a ConstInterval argument for TIME ZONE. Coerce
5375                                          * to interval and back to normalize the value and account
5376                                          * for any typmod.
5377                                          */
5378                                         Oid                     typoid;
5379                                         int32           typmod;
5380                                         Datum           interval;
5381                                         char       *intervalout;
5382
5383                                         typoid = typenameTypeId(NULL, typeName, &typmod);
5384                                         Assert(typoid == INTERVALOID);
5385
5386                                         interval =
5387                                                 DirectFunctionCall3(interval_in,
5388                                                                                         CStringGetDatum(val),
5389                                                                                         ObjectIdGetDatum(InvalidOid),
5390                                                                                         Int32GetDatum(typmod));
5391
5392                                         intervalout =
5393                                                 DatumGetCString(DirectFunctionCall1(interval_out,
5394                                                                                                                         interval));
5395                                         appendStringInfo(&buf, "INTERVAL '%s'", intervalout);
5396                                 }
5397                                 else
5398                                 {
5399                                         /*
5400                                          * Plain string literal or identifier.  For quote mode,
5401                                          * quote it if it's not a vanilla identifier.
5402                                          */
5403                                         if (flags & GUC_LIST_QUOTE)
5404                                                 appendStringInfoString(&buf, quote_identifier(val));
5405                                         else
5406                                                 appendStringInfoString(&buf, val);
5407                                 }
5408                                 break;
5409                         default:
5410                                 elog(ERROR, "unrecognized node type: %d",
5411                                          (int) nodeTag(&con->val));
5412                                 break;
5413                 }
5414         }
5415
5416         return buf.data;
5417 }
5418
5419
5420 /*
5421  * SET command
5422  */
5423 void
5424 ExecSetVariableStmt(VariableSetStmt *stmt)
5425 {
5426         GucAction       action = stmt->is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET;
5427
5428         switch (stmt->kind)
5429         {
5430                 case VAR_SET_VALUE:
5431                 case VAR_SET_CURRENT:
5432                         set_config_option(stmt->name,
5433                                                           ExtractSetVariableArgs(stmt),
5434                                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5435                                                           PGC_S_SESSION,
5436                                                           action,
5437                                                           true);
5438                         break;
5439                 case VAR_SET_MULTI:
5440
5441                         /*
5442                          * Special case for special SQL syntax that effectively sets more
5443                          * than one variable per statement.
5444                          */
5445                         if (strcmp(stmt->name, "TRANSACTION") == 0)
5446                         {
5447                                 ListCell   *head;
5448
5449                                 foreach(head, stmt->args)
5450                                 {
5451                                         DefElem    *item = (DefElem *) lfirst(head);
5452
5453                                         if (strcmp(item->defname, "transaction_isolation") == 0)
5454                                                 SetPGVariable("transaction_isolation",
5455                                                                           list_make1(item->arg), stmt->is_local);
5456                                         else if (strcmp(item->defname, "transaction_read_only") == 0)
5457                                                 SetPGVariable("transaction_read_only",
5458                                                                           list_make1(item->arg), stmt->is_local);
5459                                         else
5460                                                 elog(ERROR, "unexpected SET TRANSACTION element: %s",
5461                                                          item->defname);
5462                                 }
5463                         }
5464                         else if (strcmp(stmt->name, "SESSION CHARACTERISTICS") == 0)
5465                         {
5466                                 ListCell   *head;
5467
5468                                 foreach(head, stmt->args)
5469                                 {
5470                                         DefElem    *item = (DefElem *) lfirst(head);
5471
5472                                         if (strcmp(item->defname, "transaction_isolation") == 0)
5473                                                 SetPGVariable("default_transaction_isolation",
5474                                                                           list_make1(item->arg), stmt->is_local);
5475                                         else if (strcmp(item->defname, "transaction_read_only") == 0)
5476                                                 SetPGVariable("default_transaction_read_only",
5477                                                                           list_make1(item->arg), stmt->is_local);
5478                                         else
5479                                                 elog(ERROR, "unexpected SET SESSION element: %s",
5480                                                          item->defname);
5481                                 }
5482                         }
5483                         else
5484                                 elog(ERROR, "unexpected SET MULTI element: %s",
5485                                          stmt->name);
5486                         break;
5487                 case VAR_SET_DEFAULT:
5488                 case VAR_RESET:
5489                         set_config_option(stmt->name,
5490                                                           NULL,
5491                                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5492                                                           PGC_S_SESSION,
5493                                                           action,
5494                                                           true);
5495                         break;
5496                 case VAR_RESET_ALL:
5497                         ResetAllOptions();
5498                         break;
5499         }
5500 }
5501
5502 /*
5503  * Get the value to assign for a VariableSetStmt, or NULL if it's RESET.
5504  * The result is palloc'd.
5505  *
5506  * This is exported for use by actions such as ALTER ROLE SET.
5507  */
5508 char *
5509 ExtractSetVariableArgs(VariableSetStmt *stmt)
5510 {
5511         switch (stmt->kind)
5512         {
5513                 case VAR_SET_VALUE:
5514                         return flatten_set_variable_args(stmt->name, stmt->args);
5515                 case VAR_SET_CURRENT:
5516                         return GetConfigOptionByName(stmt->name, NULL);
5517                 default:
5518                         return NULL;
5519         }
5520 }
5521
5522 /*
5523  * SetPGVariable - SET command exported as an easily-C-callable function.
5524  *
5525  * This provides access to SET TO value, as well as SET TO DEFAULT (expressed
5526  * by passing args == NIL), but not SET FROM CURRENT functionality.
5527  */
5528 void
5529 SetPGVariable(const char *name, List *args, bool is_local)
5530 {
5531         char       *argstring = flatten_set_variable_args(name, args);
5532
5533         /* Note SET DEFAULT (argstring == NULL) is equivalent to RESET */
5534         set_config_option(name,
5535                                           argstring,
5536                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5537                                           PGC_S_SESSION,
5538                                           is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET,
5539                                           true);
5540 }
5541
5542 /*
5543  * SET command wrapped as a SQL callable function.
5544  */
5545 Datum
5546 set_config_by_name(PG_FUNCTION_ARGS)
5547 {
5548         char       *name;
5549         char       *value;
5550         char       *new_value;
5551         bool            is_local;
5552
5553         if (PG_ARGISNULL(0))
5554                 ereport(ERROR,
5555                                 (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
5556                                  errmsg("SET requires parameter name")));
5557
5558         /* Get the GUC variable name */
5559         name = TextDatumGetCString(PG_GETARG_DATUM(0));
5560
5561         /* Get the desired value or set to NULL for a reset request */
5562         if (PG_ARGISNULL(1))
5563                 value = NULL;
5564         else
5565                 value = TextDatumGetCString(PG_GETARG_DATUM(1));
5566
5567         /*
5568          * Get the desired state of is_local. Default to false if provided value
5569          * is NULL
5570          */
5571         if (PG_ARGISNULL(2))
5572                 is_local = false;
5573         else
5574                 is_local = PG_GETARG_BOOL(2);
5575
5576         /* Note SET DEFAULT (argstring == NULL) is equivalent to RESET */
5577         set_config_option(name,
5578                                           value,
5579                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5580                                           PGC_S_SESSION,
5581                                           is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET,
5582                                           true);
5583
5584         /* get the new current value */
5585         new_value = GetConfigOptionByName(name, NULL);
5586
5587         /* Convert return string to text */
5588         PG_RETURN_TEXT_P(cstring_to_text(new_value));
5589 }
5590
5591
5592 /*
5593  * Common code for DefineCustomXXXVariable subroutines: allocate the
5594  * new variable's config struct and fill in generic fields.
5595  */
5596 static struct config_generic *
5597 init_custom_variable(const char *name,
5598                                          const char *short_desc,
5599                                          const char *long_desc,
5600                                          GucContext context,
5601                                          int flags,
5602                                          enum config_type type,
5603                                          size_t sz)
5604 {
5605         struct config_generic *gen;
5606
5607         /*
5608          * Only allow custom PGC_POSTMASTER variables to be created during shared
5609          * library preload; any later than that, we can't ensure that the value
5610          * doesn't change after startup.  This is a fatal elog if it happens; just
5611          * erroring out isn't safe because we don't know what the calling loadable
5612          * module might already have hooked into.
5613          */
5614         if (context == PGC_POSTMASTER &&
5615                 !process_shared_preload_libraries_in_progress)
5616                 elog(FATAL, "cannot create PGC_POSTMASTER variables after startup");
5617
5618         gen = (struct config_generic *) guc_malloc(ERROR, sz);
5619         memset(gen, 0, sz);
5620
5621         gen->name = guc_strdup(ERROR, name);
5622         gen->context = context;
5623         gen->group = CUSTOM_OPTIONS;
5624         gen->short_desc = short_desc;
5625         gen->long_desc = long_desc;
5626         gen->flags = flags;
5627         gen->vartype = type;
5628
5629         return gen;
5630 }
5631
5632 /*
5633  * Common code for DefineCustomXXXVariable subroutines: insert the new
5634  * variable into the GUC variable array, replacing any placeholder.
5635  */
5636 static void
5637 define_custom_variable(struct config_generic * variable)
5638 {
5639         const char *name = variable->name;
5640         const char **nameAddr = &name;
5641         const char *value;
5642         struct config_string *pHolder;
5643         GucContext      phcontext;
5644         struct config_generic **res;
5645
5646         /*
5647          * See if there's a placeholder by the same name.
5648          */
5649         res = (struct config_generic **) bsearch((void *) &nameAddr,
5650                                                                                          (void *) guc_variables,
5651                                                                                          num_guc_variables,
5652                                                                                          sizeof(struct config_generic *),
5653                                                                                          guc_var_compare);
5654         if (res == NULL)
5655         {
5656                 /*
5657                  * No placeholder to replace, so we can just add it ... but first,
5658                  * make sure it's initialized to its default value.
5659                  */
5660                 InitializeOneGUCOption(variable);
5661                 add_guc_variable(variable, ERROR);
5662                 return;
5663         }
5664
5665         /*
5666          * This better be a placeholder
5667          */
5668         if (((*res)->flags & GUC_CUSTOM_PLACEHOLDER) == 0)
5669                 ereport(ERROR,
5670                                 (errcode(ERRCODE_INTERNAL_ERROR),
5671                                  errmsg("attempt to redefine parameter \"%s\"", name)));
5672
5673         Assert((*res)->vartype == PGC_STRING);
5674         pHolder = (struct config_string *) (*res);
5675
5676         /*
5677          * First, set the variable to its default value.  We must do this even
5678          * though we intend to immediately apply a new value, since it's possible
5679          * that the new value is invalid.
5680          */
5681         InitializeOneGUCOption(variable);
5682
5683         /*
5684          * Replace the placeholder. We aren't changing the name, so no re-sorting
5685          * is necessary
5686          */
5687         *res = variable;
5688
5689         /*
5690          * Infer context for assignment based on source of existing value. We
5691          * can't tell this with exact accuracy, but we can at least do something
5692          * reasonable in typical cases.
5693          */
5694         switch (pHolder->gen.source)
5695         {
5696                 case PGC_S_DEFAULT:
5697                 case PGC_S_ENV_VAR:
5698                 case PGC_S_FILE:
5699                 case PGC_S_ARGV:
5700
5701                         /*
5702                          * If we got past the check in init_custom_variable, we can safely
5703                          * assume that any existing value for a PGC_POSTMASTER variable
5704                          * was set in postmaster context.
5705                          */
5706                         if (variable->context == PGC_POSTMASTER)
5707                                 phcontext = PGC_POSTMASTER;
5708                         else
5709                                 phcontext = PGC_SIGHUP;
5710                         break;
5711                 case PGC_S_DATABASE:
5712                 case PGC_S_USER:
5713                 case PGC_S_CLIENT:
5714                 case PGC_S_SESSION:
5715                 default:
5716                         phcontext = PGC_USERSET;
5717                         break;
5718         }
5719
5720         /*
5721          * Assign the string value stored in the placeholder to the real variable.
5722          *
5723          * XXX this is not really good enough --- it should be a nontransactional
5724          * assignment, since we don't want it to roll back if the current xact
5725          * fails later.  (Or do we?)
5726          */
5727         value = *pHolder->variable;
5728
5729         if (value)
5730         {
5731                 if (set_config_option(name, value,
5732                                                           phcontext, pHolder->gen.source,
5733                                                           GUC_ACTION_SET, true))
5734                 {
5735                         /* Also copy over any saved source-location information */
5736                         if (pHolder->gen.sourcefile)
5737                                 set_config_sourcefile(name, pHolder->gen.sourcefile,
5738                                                                           pHolder->gen.sourceline);
5739                 }
5740         }
5741
5742         /*
5743          * Free up as much as we conveniently can of the placeholder structure
5744          * (this neglects any stack items...)
5745          */
5746         set_string_field(pHolder, pHolder->variable, NULL);
5747         set_string_field(pHolder, &pHolder->reset_val, NULL);
5748
5749         free(pHolder);
5750 }
5751
5752 void
5753 DefineCustomBoolVariable(const char *name,
5754                                                  const char *short_desc,
5755                                                  const char *long_desc,
5756                                                  bool *valueAddr,
5757                                                  bool bootValue,
5758                                                  GucContext context,
5759                                                  int flags,
5760                                                  GucBoolAssignHook assign_hook,
5761                                                  GucShowHook show_hook)
5762 {
5763         struct config_bool *var;
5764
5765         var = (struct config_bool *)
5766                 init_custom_variable(name, short_desc, long_desc, context, flags,
5767                                                          PGC_BOOL, sizeof(struct config_bool));
5768         var->variable = valueAddr;
5769         var->boot_val = bootValue;
5770         var->reset_val = bootValue;
5771         var->assign_hook = assign_hook;
5772         var->show_hook = show_hook;
5773         define_custom_variable(&var->gen);
5774 }
5775
5776 void
5777 DefineCustomIntVariable(const char *name,
5778                                                 const char *short_desc,
5779                                                 const char *long_desc,
5780                                                 int *valueAddr,
5781                                                 int bootValue,
5782                                                 int minValue,
5783                                                 int maxValue,
5784                                                 GucContext context,
5785                                                 int flags,
5786                                                 GucIntAssignHook assign_hook,
5787                                                 GucShowHook show_hook)
5788 {
5789         struct config_int *var;
5790
5791         var = (struct config_int *)
5792                 init_custom_variable(name, short_desc, long_desc, context, flags,
5793                                                          PGC_INT, sizeof(struct config_int));
5794         var->variable = valueAddr;
5795         var->boot_val = bootValue;
5796         var->reset_val = bootValue;
5797         var->min = minValue;
5798         var->max = maxValue;
5799         var->assign_hook = assign_hook;
5800         var->show_hook = show_hook;
5801         define_custom_variable(&var->gen);
5802 }
5803
5804 void
5805 DefineCustomRealVariable(const char *name,
5806                                                  const char *short_desc,
5807                                                  const char *long_desc,
5808                                                  double *valueAddr,
5809                                                  double bootValue,
5810                                                  double minValue,
5811                                                  double maxValue,
5812                                                  GucContext context,
5813                                                  int flags,
5814                                                  GucRealAssignHook assign_hook,
5815                                                  GucShowHook show_hook)
5816 {
5817         struct config_real *var;
5818
5819         var = (struct config_real *)
5820                 init_custom_variable(name, short_desc, long_desc, context, flags,
5821                                                          PGC_REAL, sizeof(struct config_real));
5822         var->variable = valueAddr;
5823         var->boot_val = bootValue;
5824         var->reset_val = bootValue;
5825         var->min = minValue;
5826         var->max = maxValue;
5827         var->assign_hook = assign_hook;
5828         var->show_hook = show_hook;
5829         define_custom_variable(&var->gen);
5830 }
5831
5832 void
5833 DefineCustomStringVariable(const char *name,
5834                                                    const char *short_desc,
5835                                                    const char *long_desc,
5836                                                    char **valueAddr,
5837                                                    const char *bootValue,
5838                                                    GucContext context,
5839                                                    int flags,
5840                                                    GucStringAssignHook assign_hook,
5841                                                    GucShowHook show_hook)
5842 {
5843         struct config_string *var;
5844
5845         var = (struct config_string *)
5846                 init_custom_variable(name, short_desc, long_desc, context, flags,
5847                                                          PGC_STRING, sizeof(struct config_string));
5848         var->variable = valueAddr;
5849         var->boot_val = bootValue;
5850         /* we could probably do without strdup, but keep it like normal case */
5851         if (var->boot_val)
5852                 var->reset_val = guc_strdup(ERROR, var->boot_val);
5853         var->assign_hook = assign_hook;
5854         var->show_hook = show_hook;
5855         define_custom_variable(&var->gen);
5856 }
5857
5858 void
5859 DefineCustomEnumVariable(const char *name,
5860                                                  const char *short_desc,
5861                                                  const char *long_desc,
5862                                                  int *valueAddr,
5863                                                  int bootValue,
5864                                                  const struct config_enum_entry * options,
5865                                                  GucContext context,
5866                                                  int flags,
5867                                                  GucEnumAssignHook assign_hook,
5868                                                  GucShowHook show_hook)
5869 {
5870         struct config_enum *var;
5871
5872         var = (struct config_enum *)
5873                 init_custom_variable(name, short_desc, long_desc, context, flags,
5874                                                          PGC_ENUM, sizeof(struct config_enum));
5875         var->variable = valueAddr;
5876         var->boot_val = bootValue;
5877         var->reset_val = bootValue;
5878         var->options = options;
5879         var->assign_hook = assign_hook;
5880         var->show_hook = show_hook;
5881         define_custom_variable(&var->gen);
5882 }
5883
5884 void
5885 EmitWarningsOnPlaceholders(const char *className)
5886 {
5887         int                     classLen = strlen(className);
5888         int                     i;
5889
5890         for (i = 0; i < num_guc_variables; i++)
5891         {
5892                 struct config_generic *var = guc_variables[i];
5893
5894                 if ((var->flags & GUC_CUSTOM_PLACEHOLDER) != 0 &&
5895                         strncmp(className, var->name, classLen) == 0 &&
5896                         var->name[classLen] == GUC_QUALIFIER_SEPARATOR)
5897                 {
5898                         ereport(WARNING,
5899                                         (errcode(ERRCODE_UNDEFINED_OBJECT),
5900                                          errmsg("unrecognized configuration parameter \"%s\"",
5901                                                         var->name)));
5902                 }
5903         }
5904 }
5905
5906
5907 /*
5908  * SHOW command
5909  */
5910 void
5911 GetPGVariable(const char *name, DestReceiver *dest)
5912 {
5913         if (guc_name_compare(name, "all") == 0)
5914                 ShowAllGUCConfig(dest);
5915         else
5916                 ShowGUCConfigOption(name, dest);
5917 }
5918
5919 TupleDesc
5920 GetPGVariableResultDesc(const char *name)
5921 {
5922         TupleDesc       tupdesc;
5923
5924         if (guc_name_compare(name, "all") == 0)
5925         {
5926                 /* need a tuple descriptor representing three TEXT columns */
5927                 tupdesc = CreateTemplateTupleDesc(3, false);
5928                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
5929                                                    TEXTOID, -1, 0);
5930                 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
5931                                                    TEXTOID, -1, 0);
5932                 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "description",
5933                                                    TEXTOID, -1, 0);
5934         }
5935         else
5936         {
5937                 const char *varname;
5938
5939                 /* Get the canonical spelling of name */
5940                 (void) GetConfigOptionByName(name, &varname);
5941
5942                 /* need a tuple descriptor representing a single TEXT column */
5943                 tupdesc = CreateTemplateTupleDesc(1, false);
5944                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, varname,
5945                                                    TEXTOID, -1, 0);
5946         }
5947         return tupdesc;
5948 }
5949
5950
5951 /*
5952  * SHOW command
5953  */
5954 static void
5955 ShowGUCConfigOption(const char *name, DestReceiver *dest)
5956 {
5957         TupOutputState *tstate;
5958         TupleDesc       tupdesc;
5959         const char *varname;
5960         char       *value;
5961
5962         /* Get the value and canonical spelling of name */
5963         value = GetConfigOptionByName(name, &varname);
5964
5965         /* need a tuple descriptor representing a single TEXT column */
5966         tupdesc = CreateTemplateTupleDesc(1, false);
5967         TupleDescInitEntry(tupdesc, (AttrNumber) 1, varname,
5968                                            TEXTOID, -1, 0);
5969
5970         /* prepare for projection of tuples */
5971         tstate = begin_tup_output_tupdesc(dest, tupdesc);
5972
5973         /* Send it */
5974         do_text_output_oneline(tstate, value);
5975
5976         end_tup_output(tstate);
5977 }
5978
5979 /*
5980  * SHOW ALL command
5981  */
5982 static void
5983 ShowAllGUCConfig(DestReceiver *dest)
5984 {
5985         bool            am_superuser = superuser();
5986         int                     i;
5987         TupOutputState *tstate;
5988         TupleDesc       tupdesc;
5989         char       *values[3];
5990
5991         /* need a tuple descriptor representing three TEXT columns */
5992         tupdesc = CreateTemplateTupleDesc(3, false);
5993         TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
5994                                            TEXTOID, -1, 0);
5995         TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
5996                                            TEXTOID, -1, 0);
5997         TupleDescInitEntry(tupdesc, (AttrNumber) 3, "description",
5998                                            TEXTOID, -1, 0);
5999
6000
6001         /* prepare for projection of tuples */
6002         tstate = begin_tup_output_tupdesc(dest, tupdesc);
6003
6004         for (i = 0; i < num_guc_variables; i++)
6005         {
6006                 struct config_generic *conf = guc_variables[i];
6007
6008                 if ((conf->flags & GUC_NO_SHOW_ALL) ||
6009                         ((conf->flags & GUC_SUPERUSER_ONLY) && !am_superuser))
6010                         continue;
6011
6012                 /* assign to the values array */
6013                 values[0] = (char *) conf->name;
6014                 values[1] = _ShowOption(conf, true);
6015                 values[2] = (char *) conf->short_desc;
6016
6017                 /* send it to dest */
6018                 do_tup_output(tstate, values);
6019
6020                 /* clean up */
6021                 if (values[1] != NULL)
6022                         pfree(values[1]);
6023         }
6024
6025         end_tup_output(tstate);
6026 }
6027
6028 /*
6029  * Return GUC variable value by name; optionally return canonical
6030  * form of name.  Return value is palloc'd.
6031  */
6032 char *
6033 GetConfigOptionByName(const char *name, const char **varname)
6034 {
6035         struct config_generic *record;
6036
6037         record = find_option(name, false, ERROR);
6038         if (record == NULL)
6039                 ereport(ERROR,
6040                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
6041                            errmsg("unrecognized configuration parameter \"%s\"", name)));
6042         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
6043                 ereport(ERROR,
6044                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
6045                                  errmsg("must be superuser to examine \"%s\"", name)));
6046
6047         if (varname)
6048                 *varname = record->name;
6049
6050         return _ShowOption(record, true);
6051 }
6052
6053 /*
6054  * Return GUC variable value by variable number; optionally return canonical
6055  * form of name.  Return value is palloc'd.
6056  */
6057 void
6058 GetConfigOptionByNum(int varnum, const char **values, bool *noshow)
6059 {
6060         char            buffer[256];
6061         struct config_generic *conf;
6062
6063         /* check requested variable number valid */
6064         Assert((varnum >= 0) && (varnum < num_guc_variables));
6065
6066         conf = guc_variables[varnum];
6067
6068         if (noshow)
6069         {
6070                 if ((conf->flags & GUC_NO_SHOW_ALL) ||
6071                         ((conf->flags & GUC_SUPERUSER_ONLY) && !superuser()))
6072                         *noshow = true;
6073                 else
6074                         *noshow = false;
6075         }
6076
6077         /* first get the generic attributes */
6078
6079         /* name */
6080         values[0] = conf->name;
6081
6082         /* setting : use _ShowOption in order to avoid duplicating the logic */
6083         values[1] = _ShowOption(conf, false);
6084
6085         /* unit */
6086         if (conf->vartype == PGC_INT)
6087         {
6088                 static char buf[8];
6089
6090                 switch (conf->flags & (GUC_UNIT_MEMORY | GUC_UNIT_TIME))
6091                 {
6092                         case GUC_UNIT_KB:
6093                                 values[2] = "kB";
6094                                 break;
6095                         case GUC_UNIT_BLOCKS:
6096                                 snprintf(buf, sizeof(buf), "%dkB", BLCKSZ / 1024);
6097                                 values[2] = buf;
6098                                 break;
6099                         case GUC_UNIT_XBLOCKS:
6100                                 snprintf(buf, sizeof(buf), "%dkB", XLOG_BLCKSZ / 1024);
6101                                 values[2] = buf;
6102                                 break;
6103                         case GUC_UNIT_MS:
6104                                 values[2] = "ms";
6105                                 break;
6106                         case GUC_UNIT_S:
6107                                 values[2] = "s";
6108                                 break;
6109                         case GUC_UNIT_MIN:
6110                                 values[2] = "min";
6111                                 break;
6112                         default:
6113                                 values[2] = "";
6114                                 break;
6115                 }
6116         }
6117         else
6118                 values[2] = NULL;
6119
6120         /* group */
6121         values[3] = config_group_names[conf->group];
6122
6123         /* short_desc */
6124         values[4] = conf->short_desc;
6125
6126         /* extra_desc */
6127         values[5] = conf->long_desc;
6128
6129         /* context */
6130         values[6] = GucContext_Names[conf->context];
6131
6132         /* vartype */
6133         values[7] = config_type_names[conf->vartype];
6134
6135         /* source */
6136         values[8] = GucSource_Names[conf->source];
6137
6138         /* now get the type specifc attributes */
6139         switch (conf->vartype)
6140         {
6141                 case PGC_BOOL:
6142                         {
6143                                 struct config_bool *lconf = (struct config_bool *) conf;
6144
6145                                 /* min_val */
6146                                 values[9] = NULL;
6147
6148                                 /* max_val */
6149                                 values[10] = NULL;
6150
6151                                 /* enumvals */
6152                                 values[11] = NULL;
6153
6154                                 /* boot_val */
6155                                 values[12] = pstrdup(lconf->boot_val ? "on" : "off");
6156
6157                                 /* reset_val */
6158                                 values[13] = pstrdup(lconf->reset_val ? "on" : "off");
6159                         }
6160                         break;
6161
6162                 case PGC_INT:
6163                         {
6164                                 struct config_int *lconf = (struct config_int *) conf;
6165
6166                                 /* min_val */
6167                                 snprintf(buffer, sizeof(buffer), "%d", lconf->min);
6168                                 values[9] = pstrdup(buffer);
6169
6170                                 /* max_val */
6171                                 snprintf(buffer, sizeof(buffer), "%d", lconf->max);
6172                                 values[10] = pstrdup(buffer);
6173
6174                                 /* enumvals */
6175                                 values[11] = NULL;
6176
6177                                 /* boot_val */
6178                                 snprintf(buffer, sizeof(buffer), "%d", lconf->boot_val);
6179                                 values[12] = pstrdup(buffer);
6180
6181                                 /* reset_val */
6182                                 snprintf(buffer, sizeof(buffer), "%d", lconf->reset_val);
6183                                 values[13] = pstrdup(buffer);
6184                         }
6185                         break;
6186
6187                 case PGC_REAL:
6188                         {
6189                                 struct config_real *lconf = (struct config_real *) conf;
6190
6191                                 /* min_val */
6192                                 snprintf(buffer, sizeof(buffer), "%g", lconf->min);
6193                                 values[9] = pstrdup(buffer);
6194
6195                                 /* max_val */
6196                                 snprintf(buffer, sizeof(buffer), "%g", lconf->max);
6197                                 values[10] = pstrdup(buffer);
6198
6199                                 /* enumvals */
6200                                 values[11] = NULL;
6201
6202                                 /* boot_val */
6203                                 snprintf(buffer, sizeof(buffer), "%g", lconf->boot_val);
6204                                 values[12] = pstrdup(buffer);
6205
6206                                 /* reset_val */
6207                                 snprintf(buffer, sizeof(buffer), "%g", lconf->reset_val);
6208                                 values[13] = pstrdup(buffer);
6209                         }
6210                         break;
6211
6212                 case PGC_STRING:
6213                         {
6214                                 struct config_string *lconf = (struct config_string *) conf;
6215
6216                                 /* min_val */
6217                                 values[9] = NULL;
6218
6219                                 /* max_val */
6220                                 values[10] = NULL;
6221
6222                                 /* enumvals */
6223                                 values[11] = NULL;
6224
6225                                 /* boot_val */
6226                                 if (lconf->boot_val == NULL)
6227                                         values[12] = NULL;
6228                                 else
6229                                         values[12] = pstrdup(lconf->boot_val);
6230
6231                                 /* reset_val */
6232                                 if (lconf->reset_val == NULL)
6233                                         values[13] = NULL;
6234                                 else
6235                                         values[13] = pstrdup(lconf->reset_val);
6236                         }
6237                         break;
6238
6239                 case PGC_ENUM:
6240                         {
6241                                 struct config_enum *lconf = (struct config_enum *) conf;
6242
6243                                 /* min_val */
6244                                 values[9] = NULL;
6245
6246                                 /* max_val */
6247                                 values[10] = NULL;
6248
6249                                 /* enumvals */
6250
6251                                 /*
6252                                  * NOTE! enumvals with double quotes in them are not
6253                                  * supported!
6254                                  */
6255                                 values[11] = config_enum_get_options((struct config_enum *) conf,
6256                                                                                                          "{\"", "\"}", "\",\"");
6257
6258                                 /* boot_val */
6259                                 values[12] = pstrdup(config_enum_lookup_by_value(lconf,
6260                                                                                                                    lconf->boot_val));
6261
6262                                 /* reset_val */
6263                                 values[13] = pstrdup(config_enum_lookup_by_value(lconf,
6264                                                                                                                   lconf->reset_val));
6265                         }
6266                         break;
6267
6268                 default:
6269                         {
6270                                 /*
6271                                  * should never get here, but in case we do, set 'em to NULL
6272                                  */
6273
6274                                 /* min_val */
6275                                 values[9] = NULL;
6276
6277                                 /* max_val */
6278                                 values[10] = NULL;
6279
6280                                 /* enumvals */
6281                                 values[11] = NULL;
6282
6283                                 /* boot_val */
6284                                 values[12] = NULL;
6285
6286                                 /* reset_val */
6287                                 values[13] = NULL;
6288                         }
6289                         break;
6290         }
6291
6292         /*
6293          * If the setting came from a config file, set the source location. For
6294          * security reasons, we don't show source file/line number for
6295          * non-superusers.
6296          */
6297         if (conf->source == PGC_S_FILE && superuser())
6298         {
6299                 values[14] = conf->sourcefile;
6300                 snprintf(buffer, sizeof(buffer), "%d", conf->sourceline);
6301                 values[15] = pstrdup(buffer);
6302         }
6303         else
6304         {
6305                 values[14] = NULL;
6306                 values[15] = NULL;
6307         }
6308 }
6309
6310 /*
6311  * Return the total number of GUC variables
6312  */
6313 int
6314 GetNumConfigOptions(void)
6315 {
6316         return num_guc_variables;
6317 }
6318
6319 /*
6320  * show_config_by_name - equiv to SHOW X command but implemented as
6321  * a function.
6322  */
6323 Datum
6324 show_config_by_name(PG_FUNCTION_ARGS)
6325 {
6326         char       *varname;
6327         char       *varval;
6328
6329         /* Get the GUC variable name */
6330         varname = TextDatumGetCString(PG_GETARG_DATUM(0));
6331
6332         /* Get the value */
6333         varval = GetConfigOptionByName(varname, NULL);
6334
6335         /* Convert to text */
6336         PG_RETURN_TEXT_P(cstring_to_text(varval));
6337 }
6338
6339 /*
6340  * show_all_settings - equiv to SHOW ALL command but implemented as
6341  * a Table Function.
6342  */
6343 #define NUM_PG_SETTINGS_ATTS    16
6344
6345 Datum
6346 show_all_settings(PG_FUNCTION_ARGS)
6347 {
6348         FuncCallContext *funcctx;
6349         TupleDesc       tupdesc;
6350         int                     call_cntr;
6351         int                     max_calls;
6352         AttInMetadata *attinmeta;
6353         MemoryContext oldcontext;
6354
6355         /* stuff done only on the first call of the function */
6356         if (SRF_IS_FIRSTCALL())
6357         {
6358                 /* create a function context for cross-call persistence */
6359                 funcctx = SRF_FIRSTCALL_INIT();
6360
6361                 /*
6362                  * switch to memory context appropriate for multiple function calls
6363                  */
6364                 oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
6365
6366                 /*
6367                  * need a tuple descriptor representing NUM_PG_SETTINGS_ATTS columns
6368                  * of the appropriate types
6369                  */
6370                 tupdesc = CreateTemplateTupleDesc(NUM_PG_SETTINGS_ATTS, false);
6371                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
6372                                                    TEXTOID, -1, 0);
6373                 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
6374                                                    TEXTOID, -1, 0);
6375                 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "unit",
6376                                                    TEXTOID, -1, 0);
6377                 TupleDescInitEntry(tupdesc, (AttrNumber) 4, "category",
6378                                                    TEXTOID, -1, 0);
6379                 TupleDescInitEntry(tupdesc, (AttrNumber) 5, "short_desc",
6380                                                    TEXTOID, -1, 0);
6381                 TupleDescInitEntry(tupdesc, (AttrNumber) 6, "extra_desc",
6382                                                    TEXTOID, -1, 0);
6383                 TupleDescInitEntry(tupdesc, (AttrNumber) 7, "context",
6384                                                    TEXTOID, -1, 0);
6385                 TupleDescInitEntry(tupdesc, (AttrNumber) 8, "vartype",
6386                                                    TEXTOID, -1, 0);
6387                 TupleDescInitEntry(tupdesc, (AttrNumber) 9, "source",
6388                                                    TEXTOID, -1, 0);
6389                 TupleDescInitEntry(tupdesc, (AttrNumber) 10, "min_val",
6390                                                    TEXTOID, -1, 0);
6391                 TupleDescInitEntry(tupdesc, (AttrNumber) 11, "max_val",
6392                                                    TEXTOID, -1, 0);
6393                 TupleDescInitEntry(tupdesc, (AttrNumber) 12, "enumvals",
6394                                                    TEXTARRAYOID, -1, 0);
6395                 TupleDescInitEntry(tupdesc, (AttrNumber) 13, "boot_val",
6396                                                    TEXTOID, -1, 0);
6397                 TupleDescInitEntry(tupdesc, (AttrNumber) 14, "reset_val",
6398                                                    TEXTOID, -1, 0);
6399                 TupleDescInitEntry(tupdesc, (AttrNumber) 15, "sourcefile",
6400                                                    TEXTOID, -1, 0);
6401                 TupleDescInitEntry(tupdesc, (AttrNumber) 16, "sourceline",
6402                                                    INT4OID, -1, 0);
6403
6404                 /*
6405                  * Generate attribute metadata needed later to produce tuples from raw
6406                  * C strings
6407                  */
6408                 attinmeta = TupleDescGetAttInMetadata(tupdesc);
6409                 funcctx->attinmeta = attinmeta;
6410
6411                 /* total number of tuples to be returned */
6412                 funcctx->max_calls = GetNumConfigOptions();
6413
6414                 MemoryContextSwitchTo(oldcontext);
6415         }
6416
6417         /* stuff done on every call of the function */
6418         funcctx = SRF_PERCALL_SETUP();
6419
6420         call_cntr = funcctx->call_cntr;
6421         max_calls = funcctx->max_calls;
6422         attinmeta = funcctx->attinmeta;
6423
6424         if (call_cntr < max_calls)      /* do when there is more left to send */
6425         {
6426                 char       *values[NUM_PG_SETTINGS_ATTS];
6427                 bool            noshow;
6428                 HeapTuple       tuple;
6429                 Datum           result;
6430
6431                 /*
6432                  * Get the next visible GUC variable name and value
6433                  */
6434                 do
6435                 {
6436                         GetConfigOptionByNum(call_cntr, (const char **) values, &noshow);
6437                         if (noshow)
6438                         {
6439                                 /* bump the counter and get the next config setting */
6440                                 call_cntr = ++funcctx->call_cntr;
6441
6442                                 /* make sure we haven't gone too far now */
6443                                 if (call_cntr >= max_calls)
6444                                         SRF_RETURN_DONE(funcctx);
6445                         }
6446                 } while (noshow);
6447
6448                 /* build a tuple */
6449                 tuple = BuildTupleFromCStrings(attinmeta, values);
6450
6451                 /* make the tuple into a datum */
6452                 result = HeapTupleGetDatum(tuple);
6453
6454                 SRF_RETURN_NEXT(funcctx, result);
6455         }
6456         else
6457         {
6458                 /* do when there is no more left */
6459                 SRF_RETURN_DONE(funcctx);
6460         }
6461 }
6462
6463 static char *
6464 _ShowOption(struct config_generic * record, bool use_units)
6465 {
6466         char            buffer[256];
6467         const char *val;
6468
6469         switch (record->vartype)
6470         {
6471                 case PGC_BOOL:
6472                         {
6473                                 struct config_bool *conf = (struct config_bool *) record;
6474
6475                                 if (conf->show_hook)
6476                                         val = (*conf->show_hook) ();
6477                                 else
6478                                         val = *conf->variable ? "on" : "off";
6479                         }
6480                         break;
6481
6482                 case PGC_INT:
6483                         {
6484                                 struct config_int *conf = (struct config_int *) record;
6485
6486                                 if (conf->show_hook)
6487                                         val = (*conf->show_hook) ();
6488                                 else
6489                                 {
6490                                         /*
6491                                          * Use int64 arithmetic to avoid overflows in units
6492                                          * conversion.  If INT64_IS_BUSTED we might overflow
6493                                          * anyway and print bogus answers, but there are few
6494                                          * enough such machines that it doesn't seem worth trying
6495                                          * harder.
6496                                          */
6497                                         int64           result = *conf->variable;
6498                                         const char *unit;
6499
6500                                         if (use_units && result > 0 &&
6501                                                 (record->flags & GUC_UNIT_MEMORY))
6502                                         {
6503                                                 switch (record->flags & GUC_UNIT_MEMORY)
6504                                                 {
6505                                                         case GUC_UNIT_BLOCKS:
6506                                                                 result *= BLCKSZ / 1024;
6507                                                                 break;
6508                                                         case GUC_UNIT_XBLOCKS:
6509                                                                 result *= XLOG_BLCKSZ / 1024;
6510                                                                 break;
6511                                                 }
6512
6513                                                 if (result % KB_PER_GB == 0)
6514                                                 {
6515                                                         result /= KB_PER_GB;
6516                                                         unit = "GB";
6517                                                 }
6518                                                 else if (result % KB_PER_MB == 0)
6519                                                 {
6520                                                         result /= KB_PER_MB;
6521                                                         unit = "MB";
6522                                                 }
6523                                                 else
6524                                                 {
6525                                                         unit = "kB";
6526                                                 }
6527                                         }
6528                                         else if (use_units && result > 0 &&
6529                                                          (record->flags & GUC_UNIT_TIME))
6530                                         {
6531                                                 switch (record->flags & GUC_UNIT_TIME)
6532                                                 {
6533                                                         case GUC_UNIT_S:
6534                                                                 result *= MS_PER_S;
6535                                                                 break;
6536                                                         case GUC_UNIT_MIN:
6537                                                                 result *= MS_PER_MIN;
6538                                                                 break;
6539                                                 }
6540
6541                                                 if (result % MS_PER_D == 0)
6542                                                 {
6543                                                         result /= MS_PER_D;
6544                                                         unit = "d";
6545                                                 }
6546                                                 else if (result % MS_PER_H == 0)
6547                                                 {
6548                                                         result /= MS_PER_H;
6549                                                         unit = "h";
6550                                                 }
6551                                                 else if (result % MS_PER_MIN == 0)
6552                                                 {
6553                                                         result /= MS_PER_MIN;
6554                                                         unit = "min";
6555                                                 }
6556                                                 else if (result % MS_PER_S == 0)
6557                                                 {
6558                                                         result /= MS_PER_S;
6559                                                         unit = "s";
6560                                                 }
6561                                                 else
6562                                                 {
6563                                                         unit = "ms";
6564                                                 }
6565                                         }
6566                                         else
6567                                                 unit = "";
6568
6569                                         snprintf(buffer, sizeof(buffer), INT64_FORMAT "%s",
6570                                                          result, unit);
6571                                         val = buffer;
6572                                 }
6573                         }
6574                         break;
6575
6576                 case PGC_REAL:
6577                         {
6578                                 struct config_real *conf = (struct config_real *) record;
6579
6580                                 if (conf->show_hook)
6581                                         val = (*conf->show_hook) ();
6582                                 else
6583                                 {
6584                                         snprintf(buffer, sizeof(buffer), "%g",
6585                                                          *conf->variable);
6586                                         val = buffer;
6587                                 }
6588                         }
6589                         break;
6590
6591                 case PGC_STRING:
6592                         {
6593                                 struct config_string *conf = (struct config_string *) record;
6594
6595                                 if (conf->show_hook)
6596                                         val = (*conf->show_hook) ();
6597                                 else if (*conf->variable && **conf->variable)
6598                                         val = *conf->variable;
6599                                 else
6600                                         val = "";
6601                         }
6602                         break;
6603
6604                 case PGC_ENUM:
6605                         {
6606                                 struct config_enum *conf = (struct config_enum *) record;
6607
6608                                 if (conf->show_hook)
6609                                         val = (*conf->show_hook) ();
6610                                 else
6611                                         val = config_enum_lookup_by_value(conf, *conf->variable);
6612                         }
6613                         break;
6614
6615                 default:
6616                         /* just to keep compiler quiet */
6617                         val = "???";
6618                         break;
6619         }
6620
6621         return pstrdup(val);
6622 }
6623
6624
6625 /*
6626  * Attempt (badly) to detect if a proposed new GUC setting is the same
6627  * as the current value.
6628  *
6629  * XXX this does not really work because it doesn't account for the
6630  * effects of canonicalization of string values by assign_hooks.
6631  */
6632 static bool
6633 is_newvalue_equal(struct config_generic * record, const char *newvalue)
6634 {
6635         /* newvalue == NULL isn't supported */
6636         Assert(newvalue != NULL);
6637
6638         switch (record->vartype)
6639         {
6640                 case PGC_BOOL:
6641                         {
6642                                 struct config_bool *conf = (struct config_bool *) record;
6643                                 bool            newval;
6644
6645                                 return parse_bool(newvalue, &newval)
6646                                         && *conf->variable == newval;
6647                         }
6648                 case PGC_INT:
6649                         {
6650                                 struct config_int *conf = (struct config_int *) record;
6651                                 int                     newval;
6652
6653                                 return parse_int(newvalue, &newval, record->flags, NULL)
6654                                         && *conf->variable == newval;
6655                         }
6656                 case PGC_REAL:
6657                         {
6658                                 struct config_real *conf = (struct config_real *) record;
6659                                 double          newval;
6660
6661                                 return parse_real(newvalue, &newval)
6662                                         && *conf->variable == newval;
6663                         }
6664                 case PGC_STRING:
6665                         {
6666                                 struct config_string *conf = (struct config_string *) record;
6667
6668                                 return *conf->variable != NULL &&
6669                                         strcmp(*conf->variable, newvalue) == 0;
6670                         }
6671
6672                 case PGC_ENUM:
6673                         {
6674                                 struct config_enum *conf = (struct config_enum *) record;
6675                                 int                     newval;
6676
6677                                 return config_enum_lookup_by_name(conf, newvalue, &newval) &&
6678                                         *conf->variable == newval;
6679                         }
6680         }
6681
6682         return false;
6683 }
6684
6685
6686 #ifdef EXEC_BACKEND
6687
6688 /*
6689  *      These routines dump out all non-default GUC options into a binary
6690  *      file that is read by all exec'ed backends.  The format is:
6691  *
6692  *              variable name, string, null terminated
6693  *              variable value, string, null terminated
6694  *              variable source, integer
6695  */
6696 static void
6697 write_one_nondefault_variable(FILE *fp, struct config_generic * gconf)
6698 {
6699         if (gconf->source == PGC_S_DEFAULT)
6700                 return;
6701
6702         fprintf(fp, "%s", gconf->name);
6703         fputc(0, fp);
6704
6705         switch (gconf->vartype)
6706         {
6707                 case PGC_BOOL:
6708                         {
6709                                 struct config_bool *conf = (struct config_bool *) gconf;
6710
6711                                 if (*conf->variable)
6712                                         fprintf(fp, "true");
6713                                 else
6714                                         fprintf(fp, "false");
6715                         }
6716                         break;
6717
6718                 case PGC_INT:
6719                         {
6720                                 struct config_int *conf = (struct config_int *) gconf;
6721
6722                                 fprintf(fp, "%d", *conf->variable);
6723                         }
6724                         break;
6725
6726                 case PGC_REAL:
6727                         {
6728                                 struct config_real *conf = (struct config_real *) gconf;
6729
6730                                 /* Could lose precision here? */
6731                                 fprintf(fp, "%f", *conf->variable);
6732                         }
6733                         break;
6734
6735                 case PGC_STRING:
6736                         {
6737                                 struct config_string *conf = (struct config_string *) gconf;
6738
6739                                 fprintf(fp, "%s", *conf->variable);
6740                         }
6741                         break;
6742
6743                 case PGC_ENUM:
6744                         {
6745                                 struct config_enum *conf = (struct config_enum *) gconf;
6746
6747                                 fprintf(fp, "%s",
6748                                                 config_enum_lookup_by_value(conf, *conf->variable));
6749                         }
6750                         break;
6751         }
6752
6753         fputc(0, fp);
6754
6755         fwrite(&gconf->source, sizeof(gconf->source), 1, fp);
6756 }
6757
6758 void
6759 write_nondefault_variables(GucContext context)
6760 {
6761         int                     elevel;
6762         FILE       *fp;
6763         struct config_generic *cvc_conf;
6764         int                     i;
6765
6766         Assert(context == PGC_POSTMASTER || context == PGC_SIGHUP);
6767
6768         elevel = (context == PGC_SIGHUP) ? LOG : ERROR;
6769
6770         /*
6771          * Open file
6772          */
6773         fp = AllocateFile(CONFIG_EXEC_PARAMS_NEW, "w");
6774         if (!fp)
6775         {
6776                 ereport(elevel,
6777                                 (errcode_for_file_access(),
6778                                  errmsg("could not write to file \"%s\": %m",
6779                                                 CONFIG_EXEC_PARAMS_NEW)));
6780                 return;
6781         }
6782
6783         /*
6784          * custom_variable_classes must be written out first; otherwise we might
6785          * reject custom variable values while reading the file.
6786          */
6787         cvc_conf = find_option("custom_variable_classes", false, ERROR);
6788         if (cvc_conf)
6789                 write_one_nondefault_variable(fp, cvc_conf);
6790
6791         for (i = 0; i < num_guc_variables; i++)
6792         {
6793                 struct config_generic *gconf = guc_variables[i];
6794
6795                 if (gconf != cvc_conf)
6796                         write_one_nondefault_variable(fp, gconf);
6797         }
6798
6799         if (FreeFile(fp))
6800         {
6801                 ereport(elevel,
6802                                 (errcode_for_file_access(),
6803                                  errmsg("could not write to file \"%s\": %m",
6804                                                 CONFIG_EXEC_PARAMS_NEW)));
6805                 return;
6806         }
6807
6808         /*
6809          * Put new file in place.  This could delay on Win32, but we don't hold
6810          * any exclusive locks.
6811          */
6812         rename(CONFIG_EXEC_PARAMS_NEW, CONFIG_EXEC_PARAMS);
6813 }
6814
6815
6816 /*
6817  *      Read string, including null byte from file
6818  *
6819  *      Return NULL on EOF and nothing read
6820  */
6821 static char *
6822 read_string_with_null(FILE *fp)
6823 {
6824         int                     i = 0,
6825                                 ch,
6826                                 maxlen = 256;
6827         char       *str = NULL;
6828
6829         do
6830         {
6831                 if ((ch = fgetc(fp)) == EOF)
6832                 {
6833                         if (i == 0)
6834                                 return NULL;
6835                         else
6836                                 elog(FATAL, "invalid format of exec config params file");
6837                 }
6838                 if (i == 0)
6839                         str = guc_malloc(FATAL, maxlen);
6840                 else if (i == maxlen)
6841                         str = guc_realloc(FATAL, str, maxlen *= 2);
6842                 str[i++] = ch;
6843         } while (ch != 0);
6844
6845         return str;
6846 }
6847
6848
6849 /*
6850  *      This routine loads a previous postmaster dump of its non-default
6851  *      settings.
6852  */
6853 void
6854 read_nondefault_variables(void)
6855 {
6856         FILE       *fp;
6857         char       *varname,
6858                            *varvalue;
6859         int                     varsource;
6860
6861         /*
6862          * Open file
6863          */
6864         fp = AllocateFile(CONFIG_EXEC_PARAMS, "r");
6865         if (!fp)
6866         {
6867                 /* File not found is fine */
6868                 if (errno != ENOENT)
6869                         ereport(FATAL,
6870                                         (errcode_for_file_access(),
6871                                          errmsg("could not read from file \"%s\": %m",
6872                                                         CONFIG_EXEC_PARAMS)));
6873                 return;
6874         }
6875
6876         for (;;)
6877         {
6878                 struct config_generic *record;
6879
6880                 if ((varname = read_string_with_null(fp)) == NULL)
6881                         break;
6882
6883                 if ((record = find_option(varname, true, FATAL)) == NULL)
6884                         elog(FATAL, "failed to locate variable %s in exec config params file", varname);
6885                 if ((varvalue = read_string_with_null(fp)) == NULL)
6886                         elog(FATAL, "invalid format of exec config params file");
6887                 if (fread(&varsource, sizeof(varsource), 1, fp) == 0)
6888                         elog(FATAL, "invalid format of exec config params file");
6889
6890                 (void) set_config_option(varname, varvalue, record->context,
6891                                                                  varsource, GUC_ACTION_SET, true);
6892                 free(varname);
6893                 free(varvalue);
6894         }
6895
6896         FreeFile(fp);
6897 }
6898 #endif   /* EXEC_BACKEND */
6899
6900
6901 /*
6902  * A little "long argument" simulation, although not quite GNU
6903  * compliant. Takes a string of the form "some-option=some value" and
6904  * returns name = "some_option" and value = "some value" in malloc'ed
6905  * storage. Note that '-' is converted to '_' in the option name. If
6906  * there is no '=' in the input string then value will be NULL.
6907  */
6908 void
6909 ParseLongOption(const char *string, char **name, char **value)
6910 {
6911         size_t          equal_pos;
6912         char       *cp;
6913
6914         AssertArg(string);
6915         AssertArg(name);
6916         AssertArg(value);
6917
6918         equal_pos = strcspn(string, "=");
6919
6920         if (string[equal_pos] == '=')
6921         {
6922                 *name = guc_malloc(FATAL, equal_pos + 1);
6923                 strlcpy(*name, string, equal_pos + 1);
6924
6925                 *value = guc_strdup(FATAL, &string[equal_pos + 1]);
6926         }
6927         else
6928         {
6929                 /* no equal sign in string */
6930                 *name = guc_strdup(FATAL, string);
6931                 *value = NULL;
6932         }
6933
6934         for (cp = *name; *cp; cp++)
6935                 if (*cp == '-')
6936                         *cp = '_';
6937 }
6938
6939
6940 /*
6941  * Handle options fetched from pg_database.datconfig, pg_authid.rolconfig,
6942  * pg_proc.proconfig, etc.      Caller must specify proper context/source/action.
6943  *
6944  * The array parameter must be an array of TEXT (it must not be NULL).
6945  */
6946 void
6947 ProcessGUCArray(ArrayType *array,
6948                                 GucContext context, GucSource source, GucAction action)
6949 {
6950         int                     i;
6951
6952         Assert(array != NULL);
6953         Assert(ARR_ELEMTYPE(array) == TEXTOID);
6954         Assert(ARR_NDIM(array) == 1);
6955         Assert(ARR_LBOUND(array)[0] == 1);
6956
6957         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
6958         {
6959                 Datum           d;
6960                 bool            isnull;
6961                 char       *s;
6962                 char       *name;
6963                 char       *value;
6964
6965                 d = array_ref(array, 1, &i,
6966                                           -1 /* varlenarray */ ,
6967                                           -1 /* TEXT's typlen */ ,
6968                                           false /* TEXT's typbyval */ ,
6969                                           'i' /* TEXT's typalign */ ,
6970                                           &isnull);
6971
6972                 if (isnull)
6973                         continue;
6974
6975                 s = TextDatumGetCString(d);
6976
6977                 ParseLongOption(s, &name, &value);
6978                 if (!value)
6979                 {
6980                         ereport(WARNING,
6981                                         (errcode(ERRCODE_SYNTAX_ERROR),
6982                                          errmsg("could not parse setting for parameter \"%s\"",
6983                                                         name)));
6984                         free(name);
6985                         continue;
6986                 }
6987
6988                 (void) set_config_option(name, value, context, source, action, true);
6989
6990                 free(name);
6991                 if (value)
6992                         free(value);
6993         }
6994 }
6995
6996
6997 /*
6998  * Add an entry to an option array.  The array parameter may be NULL
6999  * to indicate the current table entry is NULL.
7000  */
7001 ArrayType *
7002 GUCArrayAdd(ArrayType *array, const char *name, const char *value)
7003 {
7004         const char *varname;
7005         Datum           datum;
7006         char       *newval;
7007         ArrayType  *a;
7008
7009         Assert(name);
7010         Assert(value);
7011
7012         /* test if the option is valid */
7013         set_config_option(name, value,
7014                                           superuser() ? PGC_SUSET : PGC_USERSET,
7015                                           PGC_S_TEST, GUC_ACTION_SET, false);
7016
7017         /* convert name to canonical spelling, so we can use plain strcmp */
7018         (void) GetConfigOptionByName(name, &varname);
7019         name = varname;
7020
7021         newval = palloc(strlen(name) + 1 + strlen(value) + 1);
7022         sprintf(newval, "%s=%s", name, value);
7023         datum = CStringGetTextDatum(newval);
7024
7025         if (array)
7026         {
7027                 int                     index;
7028                 bool            isnull;
7029                 int                     i;
7030
7031                 Assert(ARR_ELEMTYPE(array) == TEXTOID);
7032                 Assert(ARR_NDIM(array) == 1);
7033                 Assert(ARR_LBOUND(array)[0] == 1);
7034
7035                 index = ARR_DIMS(array)[0] + 1; /* add after end */
7036
7037                 for (i = 1; i <= ARR_DIMS(array)[0]; i++)
7038                 {
7039                         Datum           d;
7040                         char       *current;
7041
7042                         d = array_ref(array, 1, &i,
7043                                                   -1 /* varlenarray */ ,
7044                                                   -1 /* TEXT's typlen */ ,
7045                                                   false /* TEXT's typbyval */ ,
7046                                                   'i' /* TEXT's typalign */ ,
7047                                                   &isnull);
7048                         if (isnull)
7049                                 continue;
7050                         current = TextDatumGetCString(d);
7051                         if (strncmp(current, newval, strlen(name) + 1) == 0)
7052                         {
7053                                 index = i;
7054                                 break;
7055                         }
7056                 }
7057
7058                 a = array_set(array, 1, &index,
7059                                           datum,
7060                                           false,
7061                                           -1 /* varlena array */ ,
7062                                           -1 /* TEXT's typlen */ ,
7063                                           false /* TEXT's typbyval */ ,
7064                                           'i' /* TEXT's typalign */ );
7065         }
7066         else
7067                 a = construct_array(&datum, 1,
7068                                                         TEXTOID,
7069                                                         -1, false, 'i');
7070
7071         return a;
7072 }
7073
7074
7075 /*
7076  * Delete an entry from an option array.  The array parameter may be NULL
7077  * to indicate the current table entry is NULL.  Also, if the return value
7078  * is NULL then a null should be stored.
7079  */
7080 ArrayType *
7081 GUCArrayDelete(ArrayType *array, const char *name)
7082 {
7083         const char *varname;
7084         ArrayType  *newarray;
7085         int                     i;
7086         int                     index;
7087
7088         Assert(name);
7089
7090         /* test if the option is valid */
7091         set_config_option(name, NULL,
7092                                           superuser() ? PGC_SUSET : PGC_USERSET,
7093                                           PGC_S_TEST, GUC_ACTION_SET, false);
7094
7095         /* convert name to canonical spelling, so we can use plain strcmp */
7096         (void) GetConfigOptionByName(name, &varname);
7097         name = varname;
7098
7099         /* if array is currently null, then surely nothing to delete */
7100         if (!array)
7101                 return NULL;
7102
7103         newarray = NULL;
7104         index = 1;
7105
7106         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
7107         {
7108                 Datum           d;
7109                 char       *val;
7110                 bool            isnull;
7111
7112                 d = array_ref(array, 1, &i,
7113                                           -1 /* varlenarray */ ,
7114                                           -1 /* TEXT's typlen */ ,
7115                                           false /* TEXT's typbyval */ ,
7116                                           'i' /* TEXT's typalign */ ,
7117                                           &isnull);
7118                 if (isnull)
7119                         continue;
7120                 val = TextDatumGetCString(d);
7121
7122                 /* ignore entry if it's what we want to delete */
7123                 if (strncmp(val, name, strlen(name)) == 0
7124                         && val[strlen(name)] == '=')
7125                         continue;
7126
7127                 /* else add it to the output array */
7128                 if (newarray)
7129                 {
7130                         newarray = array_set(newarray, 1, &index,
7131                                                                  d,
7132                                                                  false,
7133                                                                  -1 /* varlenarray */ ,
7134                                                                  -1 /* TEXT's typlen */ ,
7135                                                                  false /* TEXT's typbyval */ ,
7136                                                                  'i' /* TEXT's typalign */ );
7137                 }
7138                 else
7139                         newarray = construct_array(&d, 1,
7140                                                                            TEXTOID,
7141                                                                            -1, false, 'i');
7142
7143                 index++;
7144         }
7145
7146         return newarray;
7147 }
7148
7149
7150 /*
7151  * assign_hook and show_hook subroutines
7152  */
7153
7154 static const char *
7155 assign_log_destination(const char *value, bool doit, GucSource source)
7156 {
7157         char       *rawstring;
7158         List       *elemlist;
7159         ListCell   *l;
7160         int                     newlogdest = 0;
7161
7162         /* Need a modifiable copy of string */
7163         rawstring = pstrdup(value);
7164
7165         /* Parse string into list of identifiers */
7166         if (!SplitIdentifierString(rawstring, ',', &elemlist))
7167         {
7168                 /* syntax error in list */
7169                 pfree(rawstring);
7170                 list_free(elemlist);
7171                 ereport(GUC_complaint_elevel(source),
7172                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7173                    errmsg("invalid list syntax for parameter \"log_destination\"")));
7174                 return NULL;
7175         }
7176
7177         foreach(l, elemlist)
7178         {
7179                 char       *tok = (char *) lfirst(l);
7180
7181                 if (pg_strcasecmp(tok, "stderr") == 0)
7182                         newlogdest |= LOG_DESTINATION_STDERR;
7183                 else if (pg_strcasecmp(tok, "csvlog") == 0)
7184                         newlogdest |= LOG_DESTINATION_CSVLOG;
7185 #ifdef HAVE_SYSLOG
7186                 else if (pg_strcasecmp(tok, "syslog") == 0)
7187                         newlogdest |= LOG_DESTINATION_SYSLOG;
7188 #endif
7189 #ifdef WIN32
7190                 else if (pg_strcasecmp(tok, "eventlog") == 0)
7191                         newlogdest |= LOG_DESTINATION_EVENTLOG;
7192 #endif
7193                 else
7194                 {
7195                         ereport(GUC_complaint_elevel(source),
7196                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7197                                   errmsg("unrecognized \"log_destination\" key word: \"%s\"",
7198                                                  tok)));
7199                         pfree(rawstring);
7200                         list_free(elemlist);
7201                         return NULL;
7202                 }
7203         }
7204
7205         if (doit)
7206                 Log_destination = newlogdest;
7207
7208         pfree(rawstring);
7209         list_free(elemlist);
7210
7211         return value;
7212 }
7213
7214 #ifdef HAVE_SYSLOG
7215
7216 static bool
7217 assign_syslog_facility(int newval, bool doit, GucSource source)
7218 {
7219         if (doit)
7220                 set_syslog_parameters(syslog_ident_str ? syslog_ident_str : "postgres",
7221                                                           newval);
7222
7223         return true;
7224 }
7225
7226 static const char *
7227 assign_syslog_ident(const char *ident, bool doit, GucSource source)
7228 {
7229         if (doit)
7230                 set_syslog_parameters(ident, syslog_facility);
7231
7232         return ident;
7233 }
7234 #endif   /* HAVE_SYSLOG */
7235
7236
7237 static bool
7238 assign_session_replication_role(int newval, bool doit, GucSource source)
7239 {
7240         /*
7241          * Must flush the plan cache when changing replication role; but don't
7242          * flush unnecessarily.
7243          */
7244         if (doit && SessionReplicationRole != newval)
7245         {
7246                 ResetPlanCache();
7247         }
7248
7249         return true;
7250 }
7251
7252 static const char *
7253 show_num_temp_buffers(void)
7254 {
7255         /*
7256          * We show the GUC var until local buffers have been initialized, and
7257          * NLocBuffer afterwards.
7258          */
7259         static char nbuf[32];
7260
7261         sprintf(nbuf, "%d", NLocBuffer ? NLocBuffer : num_temp_buffers);
7262         return nbuf;
7263 }
7264
7265 static bool
7266 assign_phony_autocommit(bool newval, bool doit, GucSource source)
7267 {
7268         if (!newval)
7269         {
7270                 ereport(GUC_complaint_elevel(source),
7271                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
7272                                  errmsg("SET AUTOCOMMIT TO OFF is no longer supported")));
7273                 return false;
7274         }
7275         return true;
7276 }
7277
7278 static const char *
7279 assign_custom_variable_classes(const char *newval, bool doit, GucSource source)
7280 {
7281         /*
7282          * Check syntax. newval must be a comma separated list of identifiers.
7283          * Whitespace is allowed but removed from the result.
7284          */
7285         bool            hasSpaceAfterToken = false;
7286         const char *cp = newval;
7287         int                     symLen = 0;
7288         char            c;
7289         StringInfoData buf;
7290
7291         initStringInfo(&buf);
7292         while ((c = *cp++) != '\0')
7293         {
7294                 if (isspace((unsigned char) c))
7295                 {
7296                         if (symLen > 0)
7297                                 hasSpaceAfterToken = true;
7298                         continue;
7299                 }
7300
7301                 if (c == ',')
7302                 {
7303                         if (symLen > 0)         /* terminate identifier */
7304                         {
7305                                 appendStringInfoChar(&buf, ',');
7306                                 symLen = 0;
7307                         }
7308                         hasSpaceAfterToken = false;
7309                         continue;
7310                 }
7311
7312                 if (hasSpaceAfterToken || !(isalnum((unsigned char) c) || c == '_'))
7313                 {
7314                         /*
7315                          * Syntax error due to token following space after token or
7316                          * non-identifier character
7317                          */
7318                         pfree(buf.data);
7319                         return NULL;
7320                 }
7321                 appendStringInfoChar(&buf, c);
7322                 symLen++;
7323         }
7324
7325         /* Remove stray ',' at end */
7326         if (symLen == 0 && buf.len > 0)
7327                 buf.data[--buf.len] = '\0';
7328
7329         /* GUC wants the result malloc'd */
7330         newval = guc_strdup(LOG, buf.data);
7331
7332         pfree(buf.data);
7333         return newval;
7334 }
7335
7336 static bool
7337 assign_debug_assertions(bool newval, bool doit, GucSource source)
7338 {
7339 #ifndef USE_ASSERT_CHECKING
7340         if (newval)
7341         {
7342                 ereport(GUC_complaint_elevel(source),
7343                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7344                            errmsg("assertion checking is not supported by this build")));
7345                 return false;
7346         }
7347 #endif
7348         return true;
7349 }
7350
7351 static bool
7352 assign_ssl(bool newval, bool doit, GucSource source)
7353 {
7354 #ifndef USE_SSL
7355         if (newval)
7356         {
7357                 ereport(GUC_complaint_elevel(source),
7358                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7359                                  errmsg("SSL is not supported by this build")));
7360                 return false;
7361         }
7362 #endif
7363         return true;
7364 }
7365
7366 static bool
7367 assign_stage_log_stats(bool newval, bool doit, GucSource source)
7368 {
7369         if (newval && log_statement_stats)
7370         {
7371                 ereport(GUC_complaint_elevel(source),
7372                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7373                                  errmsg("cannot enable parameter when \"log_statement_stats\" is true")));
7374                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7375                 if (source != PGC_S_OVERRIDE)
7376                         return false;
7377         }
7378         return true;
7379 }
7380
7381 static bool
7382 assign_log_stats(bool newval, bool doit, GucSource source)
7383 {
7384         if (newval &&
7385                 (log_parser_stats || log_planner_stats || log_executor_stats))
7386         {
7387                 ereport(GUC_complaint_elevel(source),
7388                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7389                                  errmsg("cannot enable \"log_statement_stats\" when "
7390                                                 "\"log_parser_stats\", \"log_planner_stats\", "
7391                                                 "or \"log_executor_stats\" is true")));
7392                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7393                 if (source != PGC_S_OVERRIDE)
7394                         return false;
7395         }
7396         return true;
7397 }
7398
7399 static bool
7400 assign_transaction_read_only(bool newval, bool doit, GucSource source)
7401 {
7402         /* Can't go to r/w mode inside a r/o transaction */
7403         if (newval == false && XactReadOnly && IsSubTransaction())
7404         {
7405                 ereport(GUC_complaint_elevel(source),
7406                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7407                                  errmsg("cannot set transaction read-write mode inside a read-only transaction")));
7408                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7409                 if (source != PGC_S_OVERRIDE)
7410                         return false;
7411         }
7412         return true;
7413 }
7414
7415 static const char *
7416 assign_canonical_path(const char *newval, bool doit, GucSource source)
7417 {
7418         if (doit)
7419         {
7420                 char       *canon_val = guc_strdup(ERROR, newval);
7421
7422                 canonicalize_path(canon_val);
7423                 return canon_val;
7424         }
7425         else
7426                 return newval;
7427 }
7428
7429 static const char *
7430 assign_timezone_abbreviations(const char *newval, bool doit, GucSource source)
7431 {
7432         /*
7433          * The powerup value shown above for timezone_abbreviations is "UNKNOWN".
7434          * When we see this we just do nothing.  If this value isn't overridden
7435          * from the config file then pg_timezone_abbrev_initialize() will
7436          * eventually replace it with "Default".  This hack has two purposes: to
7437          * avoid wasting cycles loading values that might soon be overridden from
7438          * the config file, and to avoid trying to read the timezone abbrev files
7439          * during InitializeGUCOptions().  The latter doesn't work in an
7440          * EXEC_BACKEND subprocess because my_exec_path hasn't been set yet and so
7441          * we can't locate PGSHAREDIR.  (Essentially the same hack is used to
7442          * delay initializing TimeZone ... if we have any more, we should try to
7443          * clean up and centralize this mechanism ...)
7444          */
7445         if (strcmp(newval, "UNKNOWN") == 0)
7446         {
7447                 return newval;
7448         }
7449
7450         /* Loading abbrev file is expensive, so only do it when value changes */
7451         if (timezone_abbreviations_string == NULL ||
7452                 strcmp(timezone_abbreviations_string, newval) != 0)
7453         {
7454                 int                     elevel;
7455
7456                 /*
7457                  * If reading config file, only the postmaster should bleat loudly
7458                  * about problems.      Otherwise, it's just this one process doing it,
7459                  * and we use WARNING message level.
7460                  */
7461                 if (source == PGC_S_FILE)
7462                         elevel = IsUnderPostmaster ? DEBUG3 : LOG;
7463                 else
7464                         elevel = WARNING;
7465                 if (!load_tzoffsets(newval, doit, elevel))
7466                         return NULL;
7467         }
7468         return newval;
7469 }
7470
7471 /*
7472  * pg_timezone_abbrev_initialize --- set default value if not done already
7473  *
7474  * This is called after initial loading of postgresql.conf.  If no
7475  * timezone_abbreviations setting was found therein, select default.
7476  */
7477 void
7478 pg_timezone_abbrev_initialize(void)
7479 {
7480         if (strcmp(timezone_abbreviations_string, "UNKNOWN") == 0)
7481         {
7482                 SetConfigOption("timezone_abbreviations", "Default",
7483                                                 PGC_POSTMASTER, PGC_S_ARGV);
7484         }
7485 }
7486
7487 static const char *
7488 show_archive_command(void)
7489 {
7490         if (XLogArchiveMode)
7491                 return XLogArchiveCommand;
7492         else
7493                 return "(disabled)";
7494 }
7495
7496 static bool
7497 assign_tcp_keepalives_idle(int newval, bool doit, GucSource source)
7498 {
7499         if (doit)
7500                 return (pq_setkeepalivesidle(newval, MyProcPort) == STATUS_OK);
7501
7502         return true;
7503 }
7504
7505 static const char *
7506 show_tcp_keepalives_idle(void)
7507 {
7508         static char nbuf[16];
7509
7510         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesidle(MyProcPort));
7511         return nbuf;
7512 }
7513
7514 static bool
7515 assign_tcp_keepalives_interval(int newval, bool doit, GucSource source)
7516 {
7517         if (doit)
7518                 return (pq_setkeepalivesinterval(newval, MyProcPort) == STATUS_OK);
7519
7520         return true;
7521 }
7522
7523 static const char *
7524 show_tcp_keepalives_interval(void)
7525 {
7526         static char nbuf[16];
7527
7528         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesinterval(MyProcPort));
7529         return nbuf;
7530 }
7531
7532 static bool
7533 assign_tcp_keepalives_count(int newval, bool doit, GucSource source)
7534 {
7535         if (doit)
7536                 return (pq_setkeepalivescount(newval, MyProcPort) == STATUS_OK);
7537
7538         return true;
7539 }
7540
7541 static const char *
7542 show_tcp_keepalives_count(void)
7543 {
7544         static char nbuf[16];
7545
7546         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivescount(MyProcPort));
7547         return nbuf;
7548 }
7549
7550 static bool
7551 assign_maxconnections(int newval, bool doit, GucSource source)
7552 {
7553         if (newval + autovacuum_max_workers > INT_MAX / 4)
7554                 return false;
7555
7556         if (doit)
7557                 MaxBackends = newval + autovacuum_max_workers;
7558
7559         return true;
7560 }
7561
7562 static bool
7563 assign_autovacuum_max_workers(int newval, bool doit, GucSource source)
7564 {
7565         if (newval + MaxConnections > INT_MAX / 4)
7566                 return false;
7567
7568         if (doit)
7569                 MaxBackends = newval + MaxConnections;
7570
7571         return true;
7572 }
7573
7574 static bool
7575 assign_effective_io_concurrency(int newval, bool doit, GucSource source)
7576 {
7577 #ifdef USE_PREFETCH
7578         double          new_prefetch_pages = 0.0;
7579         int                     i;
7580
7581         /*----------
7582          * The user-visible GUC parameter is the number of drives (spindles),
7583          * which we need to translate to a number-of-pages-to-prefetch target.
7584          *
7585          * The expected number of prefetch pages needed to keep N drives busy is:
7586          *
7587          * drives |   I/O requests
7588          * -------+----------------
7589          *              1 |   1
7590          *              2 |   2/1 + 2/2 = 3
7591          *              3 |   3/1 + 3/2 + 3/3 = 5 1/2
7592          *              4 |   4/1 + 4/2 + 4/3 + 4/4 = 8 1/3
7593          *              n |   n * H(n)
7594          *
7595          * This is called the "coupon collector problem" and H(n) is called the
7596          * harmonic series.  This could be approximated by n * ln(n), but for
7597          * reasonable numbers of drives we might as well just compute the series.
7598          *
7599          * Alternatively we could set the target to the number of pages necessary
7600          * so that the expected number of active spindles is some arbitrary
7601          * percentage of the total.  This sounds the same but is actually slightly
7602          * different.  The result ends up being ln(1-P)/ln((n-1)/n) where P is
7603          * that desired fraction.
7604          *
7605          * Experimental results show that both of these formulas aren't aggressive
7606          * enough, but we don't really have any better proposals.
7607          *
7608          * Note that if newval = 0 (disabled), we must set target = 0.
7609          *----------
7610          */
7611
7612         for (i = 1; i <= newval; i++)
7613                 new_prefetch_pages += (double) newval / (double) i;
7614
7615         /* This range check shouldn't fail, but let's be paranoid */
7616         if (new_prefetch_pages >= 0.0 && new_prefetch_pages < (double) INT_MAX)
7617         {
7618                 if (doit)
7619                         target_prefetch_pages = (int) rint(new_prefetch_pages);
7620                 return true;
7621         }
7622         else
7623                 return false;
7624 #else
7625         return true;
7626 #endif   /* USE_PREFETCH */
7627 }
7628
7629 static const char *
7630 assign_pgstat_temp_directory(const char *newval, bool doit, GucSource source)
7631 {
7632         if (doit)
7633         {
7634                 char       *canon_val = guc_strdup(ERROR, newval);
7635                 char       *tname;
7636                 char       *fname;
7637
7638                 canonicalize_path(canon_val);
7639
7640                 tname = guc_malloc(ERROR, strlen(canon_val) + 12);              /* /pgstat.tmp */
7641                 sprintf(tname, "%s/pgstat.tmp", canon_val);
7642                 fname = guc_malloc(ERROR, strlen(canon_val) + 13);              /* /pgstat.stat */
7643                 sprintf(fname, "%s/pgstat.stat", canon_val);
7644
7645                 if (pgstat_stat_tmpname)
7646                         free(pgstat_stat_tmpname);
7647                 pgstat_stat_tmpname = tname;
7648                 if (pgstat_stat_filename)
7649                         free(pgstat_stat_filename);
7650                 pgstat_stat_filename = fname;
7651
7652                 return canon_val;
7653         }
7654         else
7655                 return newval;
7656 }
7657
7658 #include "guc-file.c"