granicus.if.org Git - postgresql/blob - 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 1.501 2009/04/07 22:22:19 momjian 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/gramparse.h"
  48 #include "parser/parse_expr.h"
  49 #include "parser/parse_relation.h"
  50 #include "parser/parse_type.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, in milliseconds."),
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, in kilobytes."),
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                 5, 0, INT_MAX, 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 duration of any statement, in milliseconds."),
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, in seconds."),
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, in seconds."),
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, in milliseconds."),
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 (in milliseconds) above "
1677                                                  "which 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 in milliseconds 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, in milliseconds."),
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, in seconds."),
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("Seconds 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("Seconds 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         {
2031                 {"bgwriter_lru_multiplier", PGC_SIGHUP, RESOURCES,
2032                         gettext_noop("Multiple of the average buffer usage to free per round."),
2033                         NULL
2034                 },
2035                 &bgwriter_lru_multiplier,
2036                 2.0, 0.0, 10.0, NULL, NULL
2037         },
2038
2039         {
2040                 {"seed", PGC_USERSET, UNGROUPED,
2041                         gettext_noop("Sets the seed for random-number generation."),
2042                         NULL,
2043                         GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2044                 },
2045                 &phony_random_seed,
2046                 0.0, -1.0, 1.0, assign_random_seed, show_random_seed
2047         },
2048
2049         {
2050                 {"autovacuum_vacuum_scale_factor", PGC_SIGHUP, AUTOVACUUM,
2051                         gettext_noop("Number of tuple updates or deletes prior to vacuum as a fraction of reltuples."),
2052                         NULL
2053                 },
2054                 &autovacuum_vac_scale,
2055                 0.2, 0.0, 100.0, NULL, NULL
2056         },
2057         {
2058                 {"autovacuum_analyze_scale_factor", PGC_SIGHUP, AUTOVACUUM,
2059                         gettext_noop("Number of tuple inserts, updates or deletes prior to analyze as a fraction of reltuples."),
2060                         NULL
2061                 },
2062                 &autovacuum_anl_scale,
2063                 0.1, 0.0, 100.0, NULL, NULL
2064         },
2065
2066         {
2067                 {"checkpoint_completion_target", PGC_SIGHUP, WAL_CHECKPOINTS,
2068                         gettext_noop("Time spent flushing dirty buffers during checkpoint, as fraction of checkpoint interval."),
2069                         NULL
2070                 },
2071                 &CheckPointCompletionTarget,
2072                 0.5, 0.0, 1.0, NULL, NULL
2073         },
2074
2075         /* End-of-list marker */
2076         {
2077                 {NULL, 0, 0, NULL, NULL}, NULL, 0.0, 0.0, 0.0, NULL, NULL
2078         }
2079 };
2080
2081
2082 static struct config_string ConfigureNamesString[] =
2083 {
2084         {
2085                 {"archive_command", PGC_SIGHUP, WAL_SETTINGS,
2086                         gettext_noop("Sets the shell command that will be called to archive a WAL file."),
2087                         NULL
2088                 },
2089                 &XLogArchiveCommand,
2090                 "", NULL, show_archive_command
2091         },
2092
2093         {
2094                 {"client_encoding", PGC_USERSET, CLIENT_CONN_LOCALE,
2095                         gettext_noop("Sets the client's character set encoding."),
2096                         NULL,
2097                         GUC_IS_NAME | GUC_REPORT
2098                 },
2099                 &client_encoding_string,
2100                 "SQL_ASCII", assign_client_encoding, NULL
2101         },
2102
2103         {
2104                 {"log_line_prefix", PGC_SIGHUP, LOGGING_WHAT,
2105                         gettext_noop("Controls information prefixed to each log line."),
2106                         gettext_noop("If blank, no prefix is used.")
2107                 },
2108                 &Log_line_prefix,
2109                 "", NULL, NULL
2110         },
2111
2112         {
2113                 {"log_timezone", PGC_SIGHUP, LOGGING_WHAT,
2114                         gettext_noop("Sets the time zone to use in log messages."),
2115                         NULL
2116                 },
2117                 &log_timezone_string,
2118                 "UNKNOWN", assign_log_timezone, show_log_timezone
2119         },
2120
2121         {
2122                 {"DateStyle", PGC_USERSET, CLIENT_CONN_LOCALE,
2123                         gettext_noop("Sets the display format for date and time values."),
2124                         gettext_noop("Also controls interpretation of ambiguous "
2125                                                  "date inputs."),
2126                         GUC_LIST_INPUT | GUC_REPORT
2127                 },
2128                 &datestyle_string,
2129                 "ISO, MDY", assign_datestyle, NULL
2130         },
2131
2132         {
2133                 {"default_tablespace", PGC_USERSET, CLIENT_CONN_STATEMENT,
2134                         gettext_noop("Sets the default tablespace to create tables and indexes in."),
2135                         gettext_noop("An empty string selects the database's default tablespace."),
2136                         GUC_IS_NAME
2137                 },
2138                 &default_tablespace,
2139                 "", assign_default_tablespace, NULL
2140         },
2141
2142         {
2143                 {"temp_tablespaces", PGC_USERSET, CLIENT_CONN_STATEMENT,
2144                         gettext_noop("Sets the tablespace(s) to use for temporary tables and sort files."),
2145                         NULL,
2146                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2147                 },
2148                 &temp_tablespaces,
2149                 "", assign_temp_tablespaces, NULL
2150         },
2151
2152         {
2153                 {"dynamic_library_path", PGC_SUSET, CLIENT_CONN_OTHER,
2154                         gettext_noop("Sets the path for dynamically loadable modules."),
2155                         gettext_noop("If a dynamically loadable module needs to be opened and "
2156                                                  "the specified name does not have a directory component (i.e., the "
2157                                                  "name does not contain a slash), the system will search this path for "
2158                                                  "the specified file."),
2159                         GUC_SUPERUSER_ONLY
2160                 },
2161                 &Dynamic_library_path,
2162                 "$libdir", NULL, NULL
2163         },
2164
2165         {
2166                 {"krb_server_keyfile", PGC_SIGHUP, CONN_AUTH_SECURITY,
2167                         gettext_noop("Sets the location of the Kerberos server key file."),
2168                         NULL,
2169                         GUC_SUPERUSER_ONLY
2170                 },
2171                 &pg_krb_server_keyfile,
2172                 PG_KRB_SRVTAB, NULL, NULL
2173         },
2174
2175         {
2176                 {"krb_srvname", PGC_SIGHUP, CONN_AUTH_SECURITY,
2177                         gettext_noop("Sets the name of the Kerberos service."),
2178                         NULL
2179                 },
2180                 &pg_krb_srvnam,
2181                 PG_KRB_SRVNAM, NULL, NULL
2182         },
2183
2184         {
2185                 {"bonjour_name", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2186                         gettext_noop("Sets the Bonjour broadcast service name."),
2187                         NULL
2188                 },
2189                 &bonjour_name,
2190                 "", NULL, NULL
2191         },
2192
2193         /* See main.c about why defaults for LC_foo are not all alike */
2194
2195         {
2196                 {"lc_collate", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2197                         gettext_noop("Shows the collation order locale."),
2198                         NULL,
2199                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2200                 },
2201                 &locale_collate,
2202                 "C", NULL, NULL
2203         },
2204
2205         {
2206                 {"lc_ctype", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2207                         gettext_noop("Shows the character classification and case conversion locale."),
2208                         NULL,
2209                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2210                 },
2211                 &locale_ctype,
2212                 "C", NULL, NULL
2213         },
2214
2215         {
2216                 {"lc_messages", PGC_SUSET, CLIENT_CONN_LOCALE,
2217                         gettext_noop("Sets the language in which messages are displayed."),
2218                         NULL
2219                 },
2220                 &locale_messages,
2221                 "", locale_messages_assign, NULL
2222         },
2223
2224         {
2225                 {"lc_monetary", PGC_USERSET, CLIENT_CONN_LOCALE,
2226                         gettext_noop("Sets the locale for formatting monetary amounts."),
2227                         NULL
2228                 },
2229                 &locale_monetary,
2230                 "C", locale_monetary_assign, NULL
2231         },
2232
2233         {
2234                 {"lc_numeric", PGC_USERSET, CLIENT_CONN_LOCALE,
2235                         gettext_noop("Sets the locale for formatting numbers."),
2236                         NULL
2237                 },
2238                 &locale_numeric,
2239                 "C", locale_numeric_assign, NULL
2240         },
2241
2242         {
2243                 {"lc_time", PGC_USERSET, CLIENT_CONN_LOCALE,
2244                         gettext_noop("Sets the locale for formatting date and time values."),
2245                         NULL
2246                 },
2247                 &locale_time,
2248                 "C", locale_time_assign, NULL
2249         },
2250
2251         {
2252                 {"shared_preload_libraries", PGC_POSTMASTER, RESOURCES_KERNEL,
2253                         gettext_noop("Lists shared libraries to preload into server."),
2254                         NULL,
2255                         GUC_LIST_INPUT | GUC_LIST_QUOTE | GUC_SUPERUSER_ONLY
2256                 },
2257                 &shared_preload_libraries_string,
2258                 "", NULL, NULL
2259         },
2260
2261         {
2262                 {"local_preload_libraries", PGC_BACKEND, CLIENT_CONN_OTHER,
2263                         gettext_noop("Lists shared libraries to preload into each backend."),
2264                         NULL,
2265                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2266                 },
2267                 &local_preload_libraries_string,
2268                 "", NULL, NULL
2269         },
2270
2271         {
2272                 {"search_path", PGC_USERSET, CLIENT_CONN_STATEMENT,
2273                         gettext_noop("Sets the schema search order for names that are not schema-qualified."),
2274                         NULL,
2275                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2276                 },
2277                 &namespace_search_path,
2278                 "\"$user\",public", assign_search_path, NULL
2279         },
2280
2281         {
2282                 /* Can't be set in postgresql.conf */
2283                 {"server_encoding", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2284                         gettext_noop("Sets the server (database) character set encoding."),
2285                         NULL,
2286                         GUC_IS_NAME | GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2287                 },
2288                 &server_encoding_string,
2289                 "SQL_ASCII", NULL, NULL
2290         },
2291
2292         {
2293                 /* Can't be set in postgresql.conf */
2294                 {"server_version", PGC_INTERNAL, PRESET_OPTIONS,
2295                         gettext_noop("Shows the server version."),
2296                         NULL,
2297                         GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2298                 },
2299                 &server_version_string,
2300                 PG_VERSION, NULL, NULL
2301         },
2302
2303         {
2304                 /* Not for general use --- used by SET ROLE */
2305                 {"role", PGC_USERSET, UNGROUPED,
2306                         gettext_noop("Sets the current role."),
2307                         NULL,
2308                         GUC_IS_NAME | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2309                 },
2310                 &role_string,
2311                 "none", assign_role, show_role
2312         },
2313
2314         {
2315                 /* Not for general use --- used by SET SESSION AUTHORIZATION */
2316                 {"session_authorization", PGC_USERSET, UNGROUPED,
2317                         gettext_noop("Sets the session user name."),
2318                         NULL,
2319                         GUC_IS_NAME | GUC_REPORT | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2320                 },
2321                 &session_authorization_string,
2322                 NULL, assign_session_authorization, show_session_authorization
2323         },
2324
2325         {
2326                 {"log_destination", PGC_SIGHUP, LOGGING_WHERE,
2327                         gettext_noop("Sets the destination for server log output."),
2328                         gettext_noop("Valid values are combinations of \"stderr\", "
2329                                                  "\"syslog\", \"csvlog\", and \"eventlog\", "
2330                                                  "depending on the platform."),
2331                         GUC_LIST_INPUT
2332                 },
2333                 &log_destination_string,
2334                 "stderr", assign_log_destination, NULL
2335         },
2336         {
2337                 {"log_directory", PGC_SIGHUP, LOGGING_WHERE,
2338                         gettext_noop("Sets the destination directory for log files."),
2339                         gettext_noop("Can be specified as relative to the data directory "
2340                                                  "or as absolute path."),
2341                         GUC_SUPERUSER_ONLY
2342                 },
2343                 &Log_directory,
2344                 "pg_log", assign_canonical_path, NULL
2345         },
2346         {
2347                 {"log_filename", PGC_SIGHUP, LOGGING_WHERE,
2348                         gettext_noop("Sets the file name pattern for log files."),
2349                         NULL,
2350                         GUC_SUPERUSER_ONLY
2351                 },
2352                 &Log_filename,
2353                 "postgresql-%Y-%m-%d_%H%M%S.log", NULL, NULL
2354         },
2355
2356 #ifdef HAVE_SYSLOG
2357         {
2358                 {"syslog_ident", PGC_SIGHUP, LOGGING_WHERE,
2359                         gettext_noop("Sets the program name used to identify PostgreSQL "
2360                                                  "messages in syslog."),
2361                         NULL
2362                 },
2363                 &syslog_ident_str,
2364                 "postgres", assign_syslog_ident, NULL
2365         },
2366 #endif
2367
2368         {
2369                 {"TimeZone", PGC_USERSET, CLIENT_CONN_LOCALE,
2370                         gettext_noop("Sets the time zone for displaying and interpreting time stamps."),
2371                         NULL,
2372                         GUC_REPORT
2373                 },
2374                 &timezone_string,
2375                 "UNKNOWN", assign_timezone, show_timezone
2376         },
2377         {
2378                 {"timezone_abbreviations", PGC_USERSET, CLIENT_CONN_LOCALE,
2379                         gettext_noop("Selects a file of time zone abbreviations."),
2380                         NULL
2381                 },
2382                 &timezone_abbreviations_string,
2383                 "UNKNOWN", assign_timezone_abbreviations, NULL
2384         },
2385
2386         {
2387                 {"transaction_isolation", PGC_USERSET, CLIENT_CONN_STATEMENT,
2388                         gettext_noop("Sets the current transaction's isolation level."),
2389                         NULL,
2390                         GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2391                 },
2392                 &XactIsoLevel_string,
2393                 NULL, assign_XactIsoLevel, show_XactIsoLevel
2394         },
2395
2396         {
2397                 {"unix_socket_group", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2398                         gettext_noop("Sets the owning group of the Unix-domain socket."),
2399                         gettext_noop("The owning user of the socket is always the user "
2400                                                  "that starts the server.")
2401                 },
2402                 &Unix_socket_group,
2403                 "", NULL, NULL
2404         },
2405
2406         {
2407                 {"unix_socket_directory", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2408                         gettext_noop("Sets the directory where the Unix-domain socket will be created."),
2409                         NULL,
2410                         GUC_SUPERUSER_ONLY
2411                 },
2412                 &UnixSocketDir,
2413                 "", assign_canonical_path, NULL
2414         },
2415
2416         {
2417                 {"listen_addresses", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2418                         gettext_noop("Sets the host name or IP address(es) to listen to."),
2419                         NULL,
2420                         GUC_LIST_INPUT
2421                 },
2422                 &ListenAddresses,
2423                 "localhost", NULL, NULL
2424         },
2425
2426         {
2427                 {"custom_variable_classes", PGC_SIGHUP, CUSTOM_OPTIONS,
2428                         gettext_noop("Sets the list of known custom variable classes."),
2429                         NULL,
2430                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2431                 },
2432                 &custom_variable_classes,
2433                 NULL, assign_custom_variable_classes, NULL
2434         },
2435
2436         {
2437                 {"data_directory", PGC_POSTMASTER, FILE_LOCATIONS,
2438                         gettext_noop("Sets the server's data directory."),
2439                         NULL,
2440                         GUC_SUPERUSER_ONLY
2441                 },
2442                 &data_directory,
2443                 NULL, NULL, NULL
2444         },
2445
2446         {
2447                 {"config_file", PGC_POSTMASTER, FILE_LOCATIONS,
2448                         gettext_noop("Sets the server's main configuration file."),
2449                         NULL,
2450                         GUC_DISALLOW_IN_FILE | GUC_SUPERUSER_ONLY
2451                 },
2452                 &ConfigFileName,
2453                 NULL, NULL, NULL
2454         },
2455
2456         {
2457                 {"hba_file", PGC_POSTMASTER, FILE_LOCATIONS,
2458                         gettext_noop("Sets the server's \"hba\" configuration file."),
2459                         NULL,
2460                         GUC_SUPERUSER_ONLY
2461                 },
2462                 &HbaFileName,
2463                 NULL, NULL, NULL
2464         },
2465
2466         {
2467                 {"ident_file", PGC_POSTMASTER, FILE_LOCATIONS,
2468                         gettext_noop("Sets the server's \"ident\" configuration file."),
2469                         NULL,
2470                         GUC_SUPERUSER_ONLY
2471                 },
2472                 &IdentFileName,
2473                 NULL, NULL, NULL
2474         },
2475
2476         {
2477                 {"external_pid_file", PGC_POSTMASTER, FILE_LOCATIONS,
2478                         gettext_noop("Writes the postmaster PID to the specified file."),
2479                         NULL,
2480                         GUC_SUPERUSER_ONLY
2481                 },
2482                 &external_pid_file,
2483                 NULL, assign_canonical_path, NULL
2484         },
2485
2486         {
2487                 {"stats_temp_directory", PGC_SIGHUP, STATS_COLLECTOR,
2488                         gettext_noop("Writes temporary statistics files to the specified directory."),
2489                         NULL,
2490                         GUC_SUPERUSER_ONLY
2491                 },
2492                 &pgstat_temp_directory,
2493                 "pg_stat_tmp", assign_pgstat_temp_directory, NULL
2494         },
2495
2496         {
2497                 {"default_text_search_config", PGC_USERSET, CLIENT_CONN_LOCALE,
2498                         gettext_noop("Sets default text search configuration."),
2499                         NULL
2500                 },
2501                 &TSCurrentConfig,
2502                 "pg_catalog.simple", assignTSCurrentConfig, NULL
2503         },
2504
2505 #ifdef USE_SSL
2506         {
2507                 {"ssl_ciphers", PGC_POSTMASTER, CONN_AUTH_SECURITY,
2508                         gettext_noop("Sets the list of allowed SSL ciphers."),
2509                         NULL,
2510                         GUC_SUPERUSER_ONLY
2511                 },
2512                 &SSLCipherSuites,
2513                 "ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH", NULL, NULL
2514         },
2515 #endif   /* USE_SSL */
2516
2517         /* End-of-list marker */
2518         {
2519                 {NULL, 0, 0, NULL, NULL}, NULL, NULL, NULL, NULL
2520         }
2521 };
2522
2523
2524 static struct config_enum ConfigureNamesEnum[] =
2525 {
2526         {
2527                 {"backslash_quote", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
2528                         gettext_noop("Sets whether \"\\'\" is allowed in string literals."),
2529                         NULL
2530                 },
2531                 &backslash_quote,
2532                 BACKSLASH_QUOTE_SAFE_ENCODING, backslash_quote_options, NULL, NULL
2533         },
2534
2535         {
2536                 {"client_min_messages", PGC_USERSET, LOGGING_WHEN,
2537                         gettext_noop("Sets the message levels that are sent to the client."),
2538                         gettext_noop("Each level includes all the levels that follow it. The later"
2539                                                  " the level, the fewer messages are sent.")
2540                 },
2541                 &client_min_messages,
2542                 NOTICE, client_message_level_options, NULL, NULL
2543         },
2544
2545         {
2546                 {"constraint_exclusion", PGC_USERSET, QUERY_TUNING_OTHER,
2547                         gettext_noop("Enables the planner to use constraints to optimize queries."),
2548                         gettext_noop("Table scans will be skipped if their constraints"
2549                                                  " guarantee that no rows match the query.")
2550                 },
2551                 &constraint_exclusion,
2552                 CONSTRAINT_EXCLUSION_PARTITION, constraint_exclusion_options,
2553                 NULL, NULL
2554         },
2555
2556         {
2557                 {"default_transaction_isolation", PGC_USERSET, CLIENT_CONN_STATEMENT,
2558                         gettext_noop("Sets the transaction isolation level of each new transaction."),
2559                         NULL
2560                 },
2561                 &DefaultXactIsoLevel,
2562                 XACT_READ_COMMITTED, isolation_level_options, NULL, NULL
2563         },
2564
2565         {
2566                 {"IntervalStyle", PGC_USERSET, CLIENT_CONN_LOCALE,
2567                         gettext_noop("Sets the display format for interval values."),
2568                         NULL,
2569                         GUC_REPORT
2570                 },
2571                 &IntervalStyle,
2572                 INTSTYLE_POSTGRES, intervalstyle_options, NULL, NULL
2573         },
2574
2575         {
2576                 {"log_error_verbosity", PGC_SUSET, LOGGING_WHEN,
2577                         gettext_noop("Sets the verbosity of logged messages."),
2578                         NULL
2579                 },
2580                 &Log_error_verbosity,
2581                 PGERROR_DEFAULT, log_error_verbosity_options, NULL, NULL
2582         },
2583
2584         {
2585                 {"log_min_messages", PGC_SUSET, LOGGING_WHEN,
2586                         gettext_noop("Sets the message levels that are logged."),
2587                         gettext_noop("Each level includes all the levels that follow it. The later"
2588                                                  " the level, the fewer messages are sent.")
2589                 },
2590                 &log_min_messages,
2591                 WARNING, server_message_level_options, NULL, NULL
2592         },
2593
2594         {
2595                 {"log_min_error_statement", PGC_SUSET, LOGGING_WHEN,
2596                         gettext_noop("Causes all statements generating error at or above this level to be logged."),
2597                         gettext_noop("Each level includes all the levels that follow it. The later"
2598                                                  " the level, the fewer messages are sent.")
2599                 },
2600                 &log_min_error_statement,
2601                 ERROR, server_message_level_options, NULL, NULL
2602         },
2603
2604         {
2605                 {"log_statement", PGC_SUSET, LOGGING_WHAT,
2606                         gettext_noop("Sets the type of statements logged."),
2607                         NULL
2608                 },
2609                 &log_statement,
2610                 LOGSTMT_NONE, log_statement_options, NULL, NULL
2611         },
2612
2613 #ifdef HAVE_SYSLOG
2614         {
2615                 {"syslog_facility", PGC_SIGHUP, LOGGING_WHERE,
2616                         gettext_noop("Sets the syslog \"facility\" to be used when syslog enabled."),
2617                         NULL
2618                 },
2619                 &syslog_facility,
2620                 LOG_LOCAL0, syslog_facility_options, assign_syslog_facility, NULL
2621         },
2622 #endif
2623
2624         {
2625                 {"regex_flavor", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
2626                         gettext_noop("Sets the regular expression \"flavor\"."),
2627                         NULL
2628                 },
2629                 &regex_flavor,
2630                 REG_ADVANCED, regex_flavor_options, NULL, NULL
2631         },
2632
2633         {
2634                 {"session_replication_role", PGC_SUSET, CLIENT_CONN_STATEMENT,
2635                         gettext_noop("Sets the session's behavior for triggers and rewrite rules."),
2636                         NULL
2637                 },
2638                 &SessionReplicationRole,
2639                 SESSION_REPLICATION_ROLE_ORIGIN, session_replication_role_options,
2640                 assign_session_replication_role, NULL
2641         },
2642
2643         {
2644                 {"track_functions", PGC_SUSET, STATS_COLLECTOR,
2645                         gettext_noop("Collects function-level statistics on database activity."),
2646                         NULL
2647                 },
2648                 &pgstat_track_functions,
2649                 TRACK_FUNC_OFF, track_function_options, NULL, NULL
2650         },
2651
2652         {
2653                 {"wal_sync_method", PGC_SIGHUP, WAL_SETTINGS,
2654                         gettext_noop("Selects the method used for forcing WAL updates to disk."),
2655                         NULL
2656                 },
2657                 &sync_method,
2658                 DEFAULT_SYNC_METHOD, sync_method_options,
2659                 assign_xlog_sync_method, NULL
2660         },
2661
2662         {
2663                 {"xmlbinary", PGC_USERSET, CLIENT_CONN_STATEMENT,
2664                         gettext_noop("Sets how binary values are to be encoded in XML."),
2665                         NULL
2666                 },
2667                 &xmlbinary,
2668                 XMLBINARY_BASE64, xmlbinary_options, NULL, NULL
2669         },
2670
2671         {
2672                 {"xmloption", PGC_USERSET, CLIENT_CONN_STATEMENT,
2673                         gettext_noop("Sets whether XML data in implicit parsing and serialization "
2674                                                  "operations is to be considered as documents or content fragments."),
2675                         NULL
2676                 },
2677                 &xmloption,
2678                 XMLOPTION_CONTENT, xmloption_options, NULL, NULL
2679         },
2680
2681
2682         /* End-of-list marker */
2683         {
2684                 {NULL, 0, 0, NULL, NULL}, NULL, 0, NULL, NULL, NULL
2685         }
2686 };
2687
2688 /******** end of options list ********/
2689
2690
2691 /*
2692  * To allow continued support of obsolete names for GUC variables, we apply
2693  * the following mappings to any unrecognized name.  Note that an old name
2694  * should be mapped to a new one only if the new variable has very similar
2695  * semantics to the old.
2696  */
2697 static const char *const map_old_guc_names[] = {
2698         "sort_mem", "work_mem",
2699         "vacuum_mem", "maintenance_work_mem",
2700         NULL
2701 };
2702
2703
2704 /*
2705  * Actual lookup of variables is done through this single, sorted array.
2706  */
2707 static struct config_generic **guc_variables;
2708
2709 /* Current number of variables contained in the vector */
2710 static int      num_guc_variables;
2711
2712 /* Vector capacity */
2713 static int      size_guc_variables;
2714
2715
2716 static bool guc_dirty;                  /* TRUE if need to do commit/abort work */
2717
2718 static bool reporting_enabled;  /* TRUE to enable GUC_REPORT */
2719
2720 static int      GUCNestLevel = 0;       /* 1 when in main transaction */
2721
2722
2723 static int      guc_var_compare(const void *a, const void *b);
2724 static int      guc_name_compare(const char *namea, const char *nameb);
2725 static void InitializeOneGUCOption(struct config_generic *gconf);
2726 static void push_old_value(struct config_generic * gconf, GucAction action);
2727 static void ReportGUCOption(struct config_generic * record);
2728 static void ShowGUCConfigOption(const char *name, DestReceiver *dest);
2729 static void ShowAllGUCConfig(DestReceiver *dest);
2730 static char *_ShowOption(struct config_generic * record, bool use_units);
2731 static bool is_newvalue_equal(struct config_generic * record, const char *newvalue);
2732
2733
2734 /*
2735  * Some infrastructure for checking malloc/strdup/realloc calls
2736  */
2737 static void *
2738 guc_malloc(int elevel, size_t size)
2739 {
2740         void       *data;
2741
2742         data = malloc(size);
2743         if (data == NULL)
2744                 ereport(elevel,
2745                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2746                                  errmsg("out of memory")));
2747         return data;
2748 }
2749
2750 static void *
2751 guc_realloc(int elevel, void *old, size_t size)
2752 {
2753         void       *data;
2754
2755         data = realloc(old, size);
2756         if (data == NULL)
2757                 ereport(elevel,
2758                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2759                                  errmsg("out of memory")));
2760         return data;
2761 }
2762
2763 static char *
2764 guc_strdup(int elevel, const char *src)
2765 {
2766         char       *data;
2767
2768         data = strdup(src);
2769         if (data == NULL)
2770                 ereport(elevel,
2771                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2772                                  errmsg("out of memory")));
2773         return data;
2774 }
2775
2776
2777 /*
2778  * Support for assigning to a field of a string GUC item.  Free the prior
2779  * value if it's not referenced anywhere else in the item (including stacked
2780  * states).
2781  */
2782 static void
2783 set_string_field(struct config_string * conf, char **field, char *newval)
2784 {
2785         char       *oldval = *field;
2786         GucStack   *stack;
2787
2788         /* Do the assignment */
2789         *field = newval;
2790
2791         /* Exit if any duplicate references, or if old value was NULL anyway */
2792         if (oldval == NULL ||
2793                 oldval == *(conf->variable) ||
2794                 oldval == conf->reset_val ||
2795                 oldval == conf->boot_val)
2796                 return;
2797         for (stack = conf->gen.stack; stack; stack = stack->prev)
2798         {
2799                 if (oldval == stack->prior.stringval ||
2800                         oldval == stack->masked.stringval)
2801                         return;
2802         }
2803
2804         /* Not used anymore, so free it */
2805         free(oldval);
2806 }
2807
2808 /*
2809  * Detect whether strval is referenced anywhere in a GUC string item
2810  */
2811 static bool
2812 string_field_used(struct config_string * conf, char *strval)
2813 {
2814         GucStack   *stack;
2815
2816         if (strval == *(conf->variable) ||
2817                 strval == conf->reset_val ||
2818                 strval == conf->boot_val)
2819                 return true;
2820         for (stack = conf->gen.stack; stack; stack = stack->prev)
2821         {
2822                 if (strval == stack->prior.stringval ||
2823                         strval == stack->masked.stringval)
2824                         return true;
2825         }
2826         return false;
2827 }
2828
2829 /*
2830  * Support for copying a variable's active value into a stack entry
2831  */
2832 static void
2833 set_stack_value(struct config_generic * gconf, union config_var_value * val)
2834 {
2835         switch (gconf->vartype)
2836         {
2837                 case PGC_BOOL:
2838                         val->boolval =
2839                                 *((struct config_bool *) gconf)->variable;
2840                         break;
2841                 case PGC_INT:
2842                         val->intval =
2843                                 *((struct config_int *) gconf)->variable;
2844                         break;
2845                 case PGC_REAL:
2846                         val->realval =
2847                                 *((struct config_real *) gconf)->variable;
2848                         break;
2849                 case PGC_STRING:
2850                         /* we assume stringval is NULL if not valid */
2851                         set_string_field((struct config_string *) gconf,
2852                                                          &(val->stringval),
2853                                                          *((struct config_string *) gconf)->variable);
2854                         break;
2855                 case PGC_ENUM:
2856                         val->enumval =
2857                                 *((struct config_enum *) gconf)->variable;
2858                         break;
2859         }
2860 }
2861
2862 /*
2863  * Support for discarding a no-longer-needed value in a stack entry
2864  */
2865 static void
2866 discard_stack_value(struct config_generic * gconf, union config_var_value * val)
2867 {
2868         switch (gconf->vartype)
2869         {
2870                 case PGC_BOOL:
2871                 case PGC_INT:
2872                 case PGC_REAL:
2873                 case PGC_ENUM:
2874                         /* no need to do anything */
2875                         break;
2876                 case PGC_STRING:
2877                         set_string_field((struct config_string *) gconf,
2878                                                          &(val->stringval),
2879                                                          NULL);
2880                         break;
2881         }
2882 }
2883
2884
2885 /*
2886  * Fetch the sorted array pointer (exported for help_config.c's use ONLY)
2887  */
2888 struct config_generic **
2889 get_guc_variables(void)
2890 {
2891         return guc_variables;
2892 }
2893
2894
2895 /*
2896  * Build the sorted array.      This is split out so that it could be
2897  * re-executed after startup (eg, we could allow loadable modules to
2898  * add vars, and then we'd need to re-sort).
2899  */
2900 void
2901 build_guc_variables(void)
2902 {
2903         int                     size_vars;
2904         int                     num_vars = 0;
2905         struct config_generic **guc_vars;
2906         int                     i;
2907
2908         for (i = 0; ConfigureNamesBool[i].gen.name; i++)
2909         {
2910                 struct config_bool *conf = &ConfigureNamesBool[i];
2911
2912                 /* Rather than requiring vartype to be filled in by hand, do this: */
2913                 conf->gen.vartype = PGC_BOOL;
2914                 num_vars++;
2915         }
2916
2917         for (i = 0; ConfigureNamesInt[i].gen.name; i++)
2918         {
2919                 struct config_int *conf = &ConfigureNamesInt[i];
2920
2921                 conf->gen.vartype = PGC_INT;
2922                 num_vars++;
2923         }
2924
2925         for (i = 0; ConfigureNamesReal[i].gen.name; i++)
2926         {
2927                 struct config_real *conf = &ConfigureNamesReal[i];
2928
2929                 conf->gen.vartype = PGC_REAL;
2930                 num_vars++;
2931         }
2932
2933         for (i = 0; ConfigureNamesString[i].gen.name; i++)
2934         {
2935                 struct config_string *conf = &ConfigureNamesString[i];
2936
2937                 conf->gen.vartype = PGC_STRING;
2938                 num_vars++;
2939         }
2940
2941         for (i = 0; ConfigureNamesEnum[i].gen.name; i++)
2942         {
2943                 struct config_enum *conf = &ConfigureNamesEnum[i];
2944
2945                 conf->gen.vartype = PGC_ENUM;
2946                 num_vars++;
2947         }
2948
2949         /*
2950          * Create table with 20% slack
2951          */
2952         size_vars = num_vars + num_vars / 4;
2953
2954         guc_vars = (struct config_generic **)
2955                 guc_malloc(FATAL, size_vars * sizeof(struct config_generic *));
2956
2957         num_vars = 0;
2958
2959         for (i = 0; ConfigureNamesBool[i].gen.name; i++)
2960                 guc_vars[num_vars++] = &ConfigureNamesBool[i].gen;
2961
2962         for (i = 0; ConfigureNamesInt[i].gen.name; i++)
2963                 guc_vars[num_vars++] = &ConfigureNamesInt[i].gen;
2964
2965         for (i = 0; ConfigureNamesReal[i].gen.name; i++)
2966                 guc_vars[num_vars++] = &ConfigureNamesReal[i].gen;
2967
2968         for (i = 0; ConfigureNamesString[i].gen.name; i++)
2969                 guc_vars[num_vars++] = &ConfigureNamesString[i].gen;
2970
2971         for (i = 0; ConfigureNamesEnum[i].gen.name; i++)
2972                 guc_vars[num_vars++] = &ConfigureNamesEnum[i].gen;
2973
2974         if (guc_variables)
2975                 free(guc_variables);
2976         guc_variables = guc_vars;
2977         num_guc_variables = num_vars;
2978         size_guc_variables = size_vars;
2979         qsort((void *) guc_variables, num_guc_variables,
2980                   sizeof(struct config_generic *), guc_var_compare);
2981 }
2982
2983 /*
2984  * Add a new GUC variable to the list of known variables. The
2985  * list is expanded if needed.
2986  */
2987 static bool
2988 add_guc_variable(struct config_generic * var, int elevel)
2989 {
2990         if (num_guc_variables + 1 >= size_guc_variables)
2991         {
2992                 /*
2993                  * Increase the vector by 25%
2994                  */
2995                 int                     size_vars = size_guc_variables + size_guc_variables / 4;
2996                 struct config_generic **guc_vars;
2997
2998                 if (size_vars == 0)
2999                 {
3000                         size_vars = 100;
3001                         guc_vars = (struct config_generic **)
3002                                 guc_malloc(elevel, size_vars * sizeof(struct config_generic *));
3003                 }
3004                 else
3005                 {
3006                         guc_vars = (struct config_generic **)
3007                                 guc_realloc(elevel, guc_variables, size_vars * sizeof(struct config_generic *));
3008                 }
3009
3010                 if (guc_vars == NULL)
3011                         return false;           /* out of memory */
3012
3013                 guc_variables = guc_vars;
3014                 size_guc_variables = size_vars;
3015         }
3016         guc_variables[num_guc_variables++] = var;
3017         qsort((void *) guc_variables, num_guc_variables,
3018                   sizeof(struct config_generic *), guc_var_compare);
3019         return true;
3020 }
3021
3022 /*
3023  * Create and add a placeholder variable. It's presumed to belong
3024  * to a valid custom variable class at this point.
3025  */
3026 static struct config_generic *
3027 add_placeholder_variable(const char *name, int elevel)
3028 {
3029         size_t          sz = sizeof(struct config_string) + sizeof(char *);
3030         struct config_string *var;
3031         struct config_generic *gen;
3032
3033         var = (struct config_string *) guc_malloc(elevel, sz);
3034         if (var == NULL)
3035                 return NULL;
3036         memset(var, 0, sz);
3037         gen = &var->gen;
3038
3039         gen->name = guc_strdup(elevel, name);
3040         if (gen->name == NULL)
3041         {
3042                 free(var);
3043                 return NULL;
3044         }
3045
3046         gen->context = PGC_USERSET;
3047         gen->group = CUSTOM_OPTIONS;
3048         gen->short_desc = "GUC placeholder variable";
3049         gen->flags = GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE | GUC_CUSTOM_PLACEHOLDER;
3050         gen->vartype = PGC_STRING;
3051
3052         /*
3053          * The char* is allocated at the end of the struct since we have no
3054          * 'static' place to point to.  Note that the current value, as well as
3055          * the boot and reset values, start out NULL.
3056          */
3057         var->variable = (char **) (var + 1);
3058
3059         if (!add_guc_variable((struct config_generic *) var, elevel))
3060         {
3061                 free((void *) gen->name);
3062                 free(var);
3063                 return NULL;
3064         }
3065
3066         return gen;
3067 }
3068
3069 /*
3070  * Detect whether the portion of "name" before dotPos matches any custom
3071  * variable class name listed in custom_var_classes.  The latter must be
3072  * formatted the way that assign_custom_variable_classes does it, ie,
3073  * no whitespace.  NULL is valid for custom_var_classes.
3074  */
3075 static bool
3076 is_custom_class(const char *name, int dotPos, const char *custom_var_classes)
3077 {
3078         bool            result = false;
3079         const char *ccs = custom_var_classes;
3080
3081         if (ccs != NULL)
3082         {
3083                 const char *start = ccs;
3084
3085                 for (;; ++ccs)
3086                 {
3087                         char            c = *ccs;
3088
3089                         if (c == '\0' || c == ',')
3090                         {
3091                                 if (dotPos == ccs - start && strncmp(start, name, dotPos) == 0)
3092                                 {
3093                                         result = true;
3094                                         break;
3095                                 }
3096                                 if (c == '\0')
3097                                         break;
3098                                 start = ccs + 1;
3099                         }
3100                 }
3101         }
3102         return result;
3103 }
3104
3105 /*
3106  * Look up option NAME.  If it exists, return a pointer to its record,
3107  * else return NULL.  If create_placeholders is TRUE, we'll create a
3108  * placeholder record for a valid-looking custom variable name.
3109  */
3110 static struct config_generic *
3111 find_option(const char *name, bool create_placeholders, int elevel)
3112 {
3113         const char **key = &name;
3114         struct config_generic **res;
3115         int                     i;
3116
3117         Assert(name);
3118
3119         /*
3120          * By equating const char ** with struct config_generic *, we are assuming
3121          * the name field is first in config_generic.
3122          */
3123         res = (struct config_generic **) bsearch((void *) &key,
3124                                                                                          (void *) guc_variables,
3125                                                                                          num_guc_variables,
3126                                                                                          sizeof(struct config_generic *),
3127                                                                                          guc_var_compare);
3128         if (res)
3129                 return *res;
3130
3131         /*
3132          * See if the name is an obsolete name for a variable.  We assume that the
3133          * set of supported old names is short enough that a brute-force search is
3134          * the best way.
3135          */
3136         for (i = 0; map_old_guc_names[i] != NULL; i += 2)
3137         {
3138                 if (guc_name_compare(name, map_old_guc_names[i]) == 0)
3139                         return find_option(map_old_guc_names[i + 1], false, elevel);
3140         }
3141
3142         if (create_placeholders)
3143         {
3144                 /*
3145                  * Check if the name is qualified, and if so, check if the qualifier
3146                  * matches any custom variable class.  If so, add a placeholder.
3147                  */
3148                 const char *dot = strchr(name, GUC_QUALIFIER_SEPARATOR);
3149
3150                 if (dot != NULL &&
3151                         is_custom_class(name, dot - name, custom_variable_classes))
3152                         return add_placeholder_variable(name, elevel);
3153         }
3154
3155         /* Unknown name */
3156         return NULL;
3157 }
3158
3159
3160 /*
3161  * comparator for qsorting and bsearching guc_variables array
3162  */
3163 static int
3164 guc_var_compare(const void *a, const void *b)
3165 {
3166         struct config_generic *confa = *(struct config_generic **) a;
3167         struct config_generic *confb = *(struct config_generic **) b;
3168
3169         return guc_name_compare(confa->name, confb->name);
3170 }
3171
3172 /*
3173  * the bare comparison function for GUC names
3174  */
3175 static int
3176 guc_name_compare(const char *namea, const char *nameb)
3177 {
3178         /*
3179          * The temptation to use strcasecmp() here must be resisted, because the
3180          * array ordering has to remain stable across setlocale() calls. So, build
3181          * our own with a simple ASCII-only downcasing.
3182          */
3183         while (*namea && *nameb)
3184         {
3185                 char            cha = *namea++;
3186                 char            chb = *nameb++;
3187
3188                 if (cha >= 'A' && cha <= 'Z')
3189                         cha += 'a' - 'A';
3190                 if (chb >= 'A' && chb <= 'Z')
3191                         chb += 'a' - 'A';
3192                 if (cha != chb)
3193                         return cha - chb;
3194         }
3195         if (*namea)
3196                 return 1;                               /* a is longer */
3197         if (*nameb)
3198                 return -1;                              /* b is longer */
3199         return 0;
3200 }
3201
3202
3203 /*
3204  * Initialize GUC options during program startup.
3205  *
3206  * Note that we cannot read the config file yet, since we have not yet
3207  * processed command-line switches.
3208  */
3209 void
3210 InitializeGUCOptions(void)
3211 {
3212         int                     i;
3213         char       *env;
3214         long            stack_rlimit;
3215
3216         /*
3217          * Before log_line_prefix could possibly receive a nonempty setting, make
3218          * sure that timezone processing is minimally alive (see elog.c).
3219          */
3220         pg_timezone_pre_initialize();
3221
3222         /*
3223          * Build sorted array of all GUC variables.
3224          */
3225         build_guc_variables();
3226
3227         /*
3228          * Load all variables with their compiled-in defaults, and initialize
3229          * status fields as needed.
3230          */
3231         for (i = 0; i < num_guc_variables; i++)
3232         {
3233                 InitializeOneGUCOption(guc_variables[i]);
3234         }
3235
3236         guc_dirty = false;
3237
3238         reporting_enabled = false;
3239
3240         /*
3241          * Prevent any attempt to override the transaction modes from
3242          * non-interactive sources.
3243          */
3244         SetConfigOption("transaction_isolation", "default",
3245                                         PGC_POSTMASTER, PGC_S_OVERRIDE);
3246         SetConfigOption("transaction_read_only", "no",
3247                                         PGC_POSTMASTER, PGC_S_OVERRIDE);
3248
3249         /*
3250          * For historical reasons, some GUC parameters can receive defaults from
3251          * environment variables.  Process those settings.      NB: if you add or
3252          * remove anything here, see also ProcessConfigFile().
3253          */
3254
3255         env = getenv("PGPORT");
3256         if (env != NULL)
3257                 SetConfigOption("port", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3258
3259         env = getenv("PGDATESTYLE");
3260         if (env != NULL)
3261                 SetConfigOption("datestyle", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3262
3263         env = getenv("PGCLIENTENCODING");
3264         if (env != NULL)
3265                 SetConfigOption("client_encoding", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3266
3267         /*
3268          * rlimit isn't exactly an "environment variable", but it behaves about
3269          * the same.  If we can identify the platform stack depth rlimit, increase
3270          * default stack depth setting up to whatever is safe (but at most 2MB).
3271          */
3272         stack_rlimit = get_stack_depth_rlimit();
3273         if (stack_rlimit > 0)
3274         {
3275                 int                     new_limit = (stack_rlimit - STACK_DEPTH_SLOP) / 1024L;
3276
3277                 if (new_limit > 100)
3278                 {
3279                         char            limbuf[16];
3280
3281                         new_limit = Min(new_limit, 2048);
3282                         sprintf(limbuf, "%d", new_limit);
3283                         SetConfigOption("max_stack_depth", limbuf,
3284                                                         PGC_POSTMASTER, PGC_S_ENV_VAR);
3285                 }
3286         }
3287 }
3288
3289 /*
3290  * Initialize one GUC option variable to its compiled-in default.
3291  */
3292 static void
3293 InitializeOneGUCOption(struct config_generic *gconf)
3294 {
3295         gconf->status = 0;
3296         gconf->reset_source = PGC_S_DEFAULT;
3297         gconf->source = PGC_S_DEFAULT;
3298         gconf->stack = NULL;
3299         gconf->sourcefile = NULL;
3300         gconf->sourceline = 0;
3301
3302         switch (gconf->vartype)
3303         {
3304                 case PGC_BOOL:
3305                 {
3306                         struct config_bool *conf = (struct config_bool *) gconf;
3307
3308                         if (conf->assign_hook)
3309                                 if (!(*conf->assign_hook) (conf->boot_val, true,
3310                                                                                    PGC_S_DEFAULT))
3311                                         elog(FATAL, "failed to initialize %s to %d",
3312                                                  conf->gen.name, (int) conf->boot_val);
3313                         *conf->variable = conf->reset_val = conf->boot_val;
3314                         break;
3315                 }
3316                 case PGC_INT:
3317                 {
3318                         struct config_int *conf = (struct config_int *) gconf;
3319
3320                         Assert(conf->boot_val >= conf->min);
3321                         Assert(conf->boot_val <= conf->max);
3322                         if (conf->assign_hook)
3323                                 if (!(*conf->assign_hook) (conf->boot_val, true,
3324                                                                                    PGC_S_DEFAULT))
3325                                         elog(FATAL, "failed to initialize %s to %d",
3326                                                  conf->gen.name, conf->boot_val);
3327                         *conf->variable = conf->reset_val = conf->boot_val;
3328                         break;
3329                 }
3330                 case PGC_REAL:
3331                 {
3332                         struct config_real *conf = (struct config_real *) gconf;
3333
3334                         Assert(conf->boot_val >= conf->min);
3335                         Assert(conf->boot_val <= conf->max);
3336                         if (conf->assign_hook)
3337                                 if (!(*conf->assign_hook) (conf->boot_val, true,
3338                                                                                    PGC_S_DEFAULT))
3339                                         elog(FATAL, "failed to initialize %s to %g",
3340                                                  conf->gen.name, conf->boot_val);
3341                         *conf->variable = conf->reset_val = conf->boot_val;
3342                         break;
3343                 }
3344                 case PGC_STRING:
3345                 {
3346                         struct config_string *conf = (struct config_string *) gconf;
3347                         char       *str;
3348
3349                         *conf->variable = NULL;
3350                         conf->reset_val = NULL;
3351
3352                         if (conf->boot_val == NULL)
3353                         {
3354                                 /* leave the value NULL, do not call assign hook */
3355                                 break;
3356                         }
3357
3358                         str = guc_strdup(FATAL, conf->boot_val);
3359                         conf->reset_val = str;
3360
3361                         if (conf->assign_hook)
3362                         {
3363                                 const char *newstr;
3364
3365                                 newstr = (*conf->assign_hook) (str, true,
3366                                                                                            PGC_S_DEFAULT);
3367                                 if (newstr == NULL)
3368                                 {
3369                                         elog(FATAL, "failed to initialize %s to \"%s\"",
3370                                                  conf->gen.name, str);
3371                                 }
3372                                 else if (newstr != str)
3373                                 {
3374                                         free(str);
3375
3376                                         /*
3377                                          * See notes in set_config_option about casting
3378                                          */
3379                                         str = (char *) newstr;
3380                                         conf->reset_val = str;
3381                                 }
3382                         }
3383                         *conf->variable = str;
3384                         break;
3385                 }
3386                 case PGC_ENUM:
3387                 {
3388                         struct config_enum *conf = (struct config_enum *) gconf;
3389
3390                         if (conf->assign_hook)
3391                                 if (!(*conf->assign_hook) (conf->boot_val, true,
3392                                                                                    PGC_S_DEFAULT))
3393                                         elog(FATAL, "failed to initialize %s to %s",
3394                                                  conf->gen.name,
3395                                                  config_enum_lookup_by_value(conf, conf->boot_val));
3396                         *conf->variable = conf->reset_val = conf->boot_val;
3397                         break;
3398                 }
3399         }
3400 }
3401
3402
3403 /*
3404  * Select the configuration files and data directory to be used, and
3405  * do the initial read of postgresql.conf.
3406  *
3407  * This is called after processing command-line switches.
3408  *              userDoption is the -D switch value if any (NULL if unspecified).
3409  *              progname is just for use in error messages.
3410  *
3411  * Returns true on success; on failure, prints a suitable error message
3412  * to stderr and returns false.
3413  */
3414 bool
3415 SelectConfigFiles(const char *userDoption, const char *progname)
3416 {
3417         char       *configdir;
3418         char       *fname;
3419         struct stat stat_buf;
3420
3421         /* configdir is -D option, or $PGDATA if no -D */
3422         if (userDoption)
3423                 configdir = make_absolute_path(userDoption);
3424         else
3425                 configdir = make_absolute_path(getenv("PGDATA"));
3426
3427         /*
3428          * Find the configuration file: if config_file was specified on the
3429          * command line, use it, else use configdir/postgresql.conf.  In any case
3430          * ensure the result is an absolute path, so that it will be interpreted
3431          * the same way by future backends.
3432          */
3433         if (ConfigFileName)
3434                 fname = make_absolute_path(ConfigFileName);
3435         else if (configdir)
3436         {
3437                 fname = guc_malloc(FATAL,
3438                                                    strlen(configdir) + strlen(CONFIG_FILENAME) + 2);
3439                 sprintf(fname, "%s/%s", configdir, CONFIG_FILENAME);
3440         }
3441         else
3442         {
3443                 write_stderr("%s does not know where to find the server configuration file.\n"
3444                                          "You must specify the --config-file or -D invocation "
3445                                          "option or set the PGDATA environment variable.\n",
3446                                          progname);
3447                 return false;
3448         }
3449
3450         /*
3451          * Set the ConfigFileName GUC variable to its final value, ensuring that
3452          * it can't be overridden later.
3453          */
3454         SetConfigOption("config_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3455         free(fname);
3456
3457         /*
3458          * Now read the config file for the first time.
3459          */
3460         if (stat(ConfigFileName, &stat_buf) != 0)
3461         {
3462                 write_stderr("%s cannot access the server configuration file \"%s\": %s\n",
3463                                          progname, ConfigFileName, strerror(errno));
3464                 return false;
3465         }
3466
3467         ProcessConfigFile(PGC_POSTMASTER);
3468
3469         /*
3470          * If the data_directory GUC variable has been set, use that as DataDir;
3471          * otherwise use configdir if set; else punt.
3472          *
3473          * Note: SetDataDir will copy and absolute-ize its argument, so we don't
3474          * have to.
3475          */
3476         if (data_directory)
3477                 SetDataDir(data_directory);
3478         else if (configdir)
3479                 SetDataDir(configdir);
3480         else
3481         {
3482                 write_stderr("%s does not know where to find the database system data.\n"
3483                                          "This can be specified as \"data_directory\" in \"%s\", "
3484                                          "or by the -D invocation option, or by the "
3485                                          "PGDATA environment variable.\n",
3486                                          progname, ConfigFileName);
3487                 return false;
3488         }
3489
3490         /*
3491          * Reflect the final DataDir value back into the data_directory GUC var.
3492          * (If you are wondering why we don't just make them a single variable,
3493          * it's because the EXEC_BACKEND case needs DataDir to be transmitted to
3494          * child backends specially.  XXX is that still true?  Given that we now
3495          * chdir to DataDir, EXEC_BACKEND can read the config file without knowing
3496          * DataDir in advance.)
3497          */
3498         SetConfigOption("data_directory", DataDir, PGC_POSTMASTER, PGC_S_OVERRIDE);
3499
3500         /*
3501          * Figure out where pg_hba.conf is, and make sure the path is absolute.
3502          */
3503         if (HbaFileName)
3504                 fname = make_absolute_path(HbaFileName);
3505         else if (configdir)
3506         {
3507                 fname = guc_malloc(FATAL,
3508                                                    strlen(configdir) + strlen(HBA_FILENAME) + 2);
3509                 sprintf(fname, "%s/%s", configdir, HBA_FILENAME);
3510         }
3511         else
3512         {
3513                 write_stderr("%s does not know where to find the \"hba\" configuration file.\n"
3514                                          "This can be specified as \"hba_file\" in \"%s\", "
3515                                          "or by the -D invocation option, or by the "
3516                                          "PGDATA environment variable.\n",
3517                                          progname, ConfigFileName);
3518                 return false;
3519         }
3520         SetConfigOption("hba_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3521         free(fname);
3522
3523         /*
3524          * Likewise for pg_ident.conf.
3525          */
3526         if (IdentFileName)
3527                 fname = make_absolute_path(IdentFileName);
3528         else if (configdir)
3529         {
3530                 fname = guc_malloc(FATAL,
3531                                                    strlen(configdir) + strlen(IDENT_FILENAME) + 2);
3532                 sprintf(fname, "%s/%s", configdir, IDENT_FILENAME);
3533         }
3534         else
3535         {
3536                 write_stderr("%s does not know where to find the \"ident\" configuration file.\n"
3537                                          "This can be specified as \"ident_file\" in \"%s\", "
3538                                          "or by the -D invocation option, or by the "
3539                                          "PGDATA environment variable.\n",
3540                                          progname, ConfigFileName);
3541                 return false;
3542         }
3543         SetConfigOption("ident_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3544         free(fname);
3545
3546         free(configdir);
3547
3548         return true;
3549 }
3550
3551
3552 /*
3553  * Reset all options to their saved default values (implements RESET ALL)
3554  */
3555 void
3556 ResetAllOptions(void)
3557 {
3558         int                     i;
3559
3560         for (i = 0; i < num_guc_variables; i++)
3561         {
3562                 struct config_generic *gconf = guc_variables[i];
3563
3564                 /* Don't reset non-SET-able values */
3565                 if (gconf->context != PGC_SUSET &&
3566                         gconf->context != PGC_USERSET)
3567                         continue;
3568                 /* Don't reset if special exclusion from RESET ALL */
3569                 if (gconf->flags & GUC_NO_RESET_ALL)
3570                         continue;
3571                 /* No need to reset if wasn't SET */
3572                 if (gconf->source <= PGC_S_OVERRIDE)
3573                         continue;
3574
3575                 /* Save old value to support transaction abort */
3576                 push_old_value(gconf, GUC_ACTION_SET);
3577
3578                 switch (gconf->vartype)
3579                 {
3580                         case PGC_BOOL:
3581                                 {
3582                                         struct config_bool *conf = (struct config_bool *) gconf;
3583
3584                                         if (conf->assign_hook)
3585                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3586                                                                                                    PGC_S_SESSION))
3587                                                         elog(ERROR, "failed to reset %s to %d",
3588                                                                  conf->gen.name, (int) conf->reset_val);
3589                                         *conf->variable = conf->reset_val;
3590                                         break;
3591                                 }
3592                         case PGC_INT:
3593                                 {
3594                                         struct config_int *conf = (struct config_int *) gconf;
3595
3596                                         if (conf->assign_hook)
3597                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3598                                                                                                    PGC_S_SESSION))
3599                                                         elog(ERROR, "failed to reset %s to %d",
3600                                                                  conf->gen.name, conf->reset_val);
3601                                         *conf->variable = conf->reset_val;
3602                                         break;
3603                                 }
3604                         case PGC_REAL:
3605                                 {
3606                                         struct config_real *conf = (struct config_real *) gconf;
3607
3608                                         if (conf->assign_hook)
3609                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3610                                                                                                    PGC_S_SESSION))
3611                                                         elog(ERROR, "failed to reset %s to %g",
3612                                                                  conf->gen.name, conf->reset_val);
3613                                         *conf->variable = conf->reset_val;
3614                                         break;
3615                                 }
3616                         case PGC_STRING:
3617                                 {
3618                                         struct config_string *conf = (struct config_string *) gconf;
3619                                         char       *str;
3620
3621                                         /* We need not strdup here */
3622                                         str = conf->reset_val;
3623
3624                                         if (conf->assign_hook && str)
3625                                         {
3626                                                 const char *newstr;
3627
3628                                                 newstr = (*conf->assign_hook) (str, true,
3629                                                                                                            PGC_S_SESSION);
3630                                                 if (newstr == NULL)
3631                                                         elog(ERROR, "failed to reset %s to \"%s\"",
3632                                                                  conf->gen.name, str);
3633                                                 else if (newstr != str)
3634                                                 {
3635                                                         /*
3636                                                          * See notes in set_config_option about casting
3637                                                          */
3638                                                         str = (char *) newstr;
3639                                                 }
3640                                         }
3641
3642                                         set_string_field(conf, conf->variable, str);
3643                                         break;
3644                                 }
3645                         case PGC_ENUM:
3646                                 {
3647                                         struct config_enum *conf = (struct config_enum *) gconf;
3648
3649                                         if (conf->assign_hook)
3650                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3651                                                                                                    PGC_S_SESSION))
3652                                                         elog(ERROR, "failed to reset %s to %s",
3653                                                                  conf->gen.name,
3654                                                                  config_enum_lookup_by_value(conf, conf->reset_val));
3655                                         *conf->variable = conf->reset_val;
3656                                         break;
3657                                 }
3658                 }
3659
3660                 gconf->source = gconf->reset_source;
3661
3662                 if (gconf->flags & GUC_REPORT)
3663                         ReportGUCOption(gconf);
3664         }
3665 }
3666
3667
3668 /*
3669  * push_old_value
3670  *              Push previous state during transactional assignment to a GUC variable.
3671  */
3672 static void
3673 push_old_value(struct config_generic * gconf, GucAction action)
3674 {
3675         GucStack   *stack;
3676
3677         /* If we're not inside a nest level, do nothing */
3678         if (GUCNestLevel == 0)
3679                 return;
3680
3681         /* Do we already have a stack entry of the current nest level? */
3682         stack = gconf->stack;
3683         if (stack && stack->nest_level >= GUCNestLevel)
3684         {
3685                 /* Yes, so adjust its state if necessary */
3686                 Assert(stack->nest_level == GUCNestLevel);
3687                 switch (action)
3688                 {
3689                         case GUC_ACTION_SET:
3690                                 /* SET overrides any prior action at same nest level */
3691                                 if (stack->state == GUC_SET_LOCAL)
3692                                 {
3693                                         /* must discard old masked value */
3694                                         discard_stack_value(gconf, &stack->masked);
3695                                 }
3696                                 stack->state = GUC_SET;
3697                                 break;
3698                         case GUC_ACTION_LOCAL:
3699                                 if (stack->state == GUC_SET)
3700                                 {
3701                                         /* SET followed by SET LOCAL, remember SET's value */
3702                                         set_stack_value(gconf, &stack->masked);
3703                                         stack->state = GUC_SET_LOCAL;
3704                                 }
3705                                 /* in all other cases, no change to stack entry */
3706                                 break;
3707                         case GUC_ACTION_SAVE:
3708                                 /* Could only have a prior SAVE of same variable */
3709                                 Assert(stack->state == GUC_SAVE);
3710                                 break;
3711                 }
3712                 Assert(guc_dirty);              /* must be set already */
3713                 return;
3714         }
3715
3716         /*
3717          * Push a new stack entry
3718          *
3719          * We keep all the stack entries in TopTransactionContext for simplicity.
3720          */
3721         stack = (GucStack *) MemoryContextAllocZero(TopTransactionContext,
3722                                                                                                 sizeof(GucStack));
3723
3724         stack->prev = gconf->stack;
3725         stack->nest_level = GUCNestLevel;
3726         switch (action)
3727         {
3728                 case GUC_ACTION_SET:
3729                         stack->state = GUC_SET;
3730                         break;
3731                 case GUC_ACTION_LOCAL:
3732                         stack->state = GUC_LOCAL;
3733                         break;
3734                 case GUC_ACTION_SAVE:
3735                         stack->state = GUC_SAVE;
3736                         break;
3737         }
3738         stack->source = gconf->source;
3739         set_stack_value(gconf, &stack->prior);
3740
3741         gconf->stack = stack;
3742
3743         /* Ensure we remember to pop at end of xact */
3744         guc_dirty = true;
3745 }
3746
3747
3748 /*
3749  * Do GUC processing at main transaction start.
3750  */
3751 void
3752 AtStart_GUC(void)
3753 {
3754         /*
3755          * The nest level should be 0 between transactions; if it isn't, somebody
3756          * didn't call AtEOXact_GUC, or called it with the wrong nestLevel.  We
3757          * throw a warning but make no other effort to clean up.
3758          */
3759         if (GUCNestLevel != 0)
3760                 elog(WARNING, "GUC nest level = %d at transaction start",
3761                          GUCNestLevel);
3762         GUCNestLevel = 1;
3763 }
3764
3765 /*
3766  * Enter a new nesting level for GUC values.  This is called at subtransaction
3767  * start and when entering a function that has proconfig settings.      NOTE that
3768  * we must not risk error here, else subtransaction start will be unhappy.
3769  */
3770 int
3771 NewGUCNestLevel(void)
3772 {
3773         return ++GUCNestLevel;
3774 }
3775
3776 /*
3777  * Do GUC processing at transaction or subtransaction commit or abort, or
3778  * when exiting a function that has proconfig settings.  (The name is thus
3779  * a bit of a misnomer; perhaps it should be ExitGUCNestLevel or some such.)
3780  * During abort, we discard all GUC settings that were applied at nesting
3781  * levels >= nestLevel.  nestLevel == 1 corresponds to the main transaction.
3782  */
3783 void
3784 AtEOXact_GUC(bool isCommit, int nestLevel)
3785 {
3786         bool            still_dirty;
3787         int                     i;
3788
3789         Assert(nestLevel > 0 && nestLevel <= GUCNestLevel);
3790
3791         /* Quick exit if nothing's changed in this transaction */
3792         if (!guc_dirty)
3793         {
3794                 GUCNestLevel = nestLevel - 1;
3795                 return;
3796         }
3797
3798         still_dirty = false;
3799         for (i = 0; i < num_guc_variables; i++)
3800         {
3801                 struct config_generic *gconf = guc_variables[i];
3802                 GucStack   *stack;
3803
3804                 /*
3805                  * Process and pop each stack entry within the nest level.      To
3806                  * simplify fmgr_security_definer(), we allow failure exit from a
3807                  * function-with-SET-options to be recovered at the surrounding
3808                  * transaction or subtransaction abort; so there could be more than
3809                  * one stack entry to pop.
3810                  */
3811                 while ((stack = gconf->stack) != NULL &&
3812                            stack->nest_level >= nestLevel)
3813                 {
3814                         GucStack   *prev = stack->prev;
3815                         bool            restorePrior = false;
3816                         bool            restoreMasked = false;
3817                         bool            changed;
3818
3819                         /*
3820                          * In this next bit, if we don't set either restorePrior or
3821                          * restoreMasked, we must "discard" any unwanted fields of the
3822                          * stack entries to avoid leaking memory.  If we do set one of
3823                          * those flags, unused fields will be cleaned up after restoring.
3824                          */
3825                         if (!isCommit)          /* if abort, always restore prior value */
3826                                 restorePrior = true;
3827                         else if (stack->state == GUC_SAVE)
3828                                 restorePrior = true;
3829                         else if (stack->nest_level == 1)
3830                         {
3831                                 /* transaction commit */
3832                                 if (stack->state == GUC_SET_LOCAL)
3833                                         restoreMasked = true;
3834                                 else if (stack->state == GUC_SET)
3835                                 {
3836                                         /* we keep the current active value */
3837                                         discard_stack_value(gconf, &stack->prior);
3838                                 }
3839                                 else    /* must be GUC_LOCAL */
3840                                         restorePrior = true;
3841                         }
3842                         else if (prev == NULL ||
3843                                          prev->nest_level < stack->nest_level - 1)
3844                         {
3845                                 /* decrement entry's level and do not pop it */
3846                                 stack->nest_level--;
3847                                 continue;
3848                         }
3849                         else
3850                         {
3851                                 /*
3852                                  * We have to merge this stack entry into prev. See README for
3853                                  * discussion of this bit.
3854                                  */
3855                                 switch (stack->state)
3856                                 {
3857                                         case GUC_SAVE:
3858                                                 Assert(false);  /* can't get here */
3859
3860                                         case GUC_SET:
3861                                                 /* next level always becomes SET */
3862                                                 discard_stack_value(gconf, &stack->prior);
3863                                                 if (prev->state == GUC_SET_LOCAL)
3864                                                         discard_stack_value(gconf, &prev->masked);
3865                                                 prev->state = GUC_SET;
3866                                                 break;
3867
3868                                         case GUC_LOCAL:
3869                                                 if (prev->state == GUC_SET)
3870                                                 {
3871                                                         /* LOCAL migrates down */
3872                                                         prev->masked = stack->prior;
3873                                                         prev->state = GUC_SET_LOCAL;
3874                                                 }
3875                                                 else
3876                                                 {
3877                                                         /* else just forget this stack level */
3878                                                         discard_stack_value(gconf, &stack->prior);
3879                                                 }
3880                                                 break;
3881
3882                                         case GUC_SET_LOCAL:
3883                                                 /* prior state at this level no longer wanted */
3884                                                 discard_stack_value(gconf, &stack->prior);
3885                                                 /* copy down the masked state */
3886                                                 if (prev->state == GUC_SET_LOCAL)
3887                                                         discard_stack_value(gconf, &prev->masked);
3888                                                 prev->masked = stack->masked;
3889                                                 prev->state = GUC_SET_LOCAL;
3890                                                 break;
3891                                 }
3892                         }
3893
3894                         changed = false;
3895
3896                         if (restorePrior || restoreMasked)
3897                         {
3898                                 /* Perform appropriate restoration of the stacked value */
3899                                 union config_var_value newvalue;
3900                                 GucSource       newsource;
3901
3902                                 if (restoreMasked)
3903                                 {
3904                                         newvalue = stack->masked;
3905                                         newsource = PGC_S_SESSION;
3906                                 }
3907                                 else
3908                                 {
3909                                         newvalue = stack->prior;
3910                                         newsource = stack->source;
3911                                 }
3912
3913                                 switch (gconf->vartype)
3914                                 {
3915                                         case PGC_BOOL:
3916                                                 {
3917                                                         struct config_bool *conf = (struct config_bool *) gconf;
3918                                                         bool            newval = newvalue.boolval;
3919
3920                                                         if (*conf->variable != newval)
3921                                                         {
3922                                                                 if (conf->assign_hook)
3923                                                                         if (!(*conf->assign_hook) (newval,
3924                                                                                                            true, PGC_S_OVERRIDE))
3925                                                                                 elog(LOG, "failed to commit %s as %d",
3926                                                                                          conf->gen.name, (int) newval);
3927                                                                 *conf->variable = newval;
3928                                                                 changed = true;
3929                                                         }
3930                                                         break;
3931                                                 }
3932                                         case PGC_INT:
3933                                                 {
3934                                                         struct config_int *conf = (struct config_int *) gconf;
3935                                                         int                     newval = newvalue.intval;
3936
3937                                                         if (*conf->variable != newval)
3938                                                         {
3939                                                                 if (conf->assign_hook)
3940                                                                         if (!(*conf->assign_hook) (newval,
3941                                                                                                            true, PGC_S_OVERRIDE))
3942                                                                                 elog(LOG, "failed to commit %s as %d",
3943                                                                                          conf->gen.name, newval);
3944                                                                 *conf->variable = newval;
3945                                                                 changed = true;
3946                                                         }
3947                                                         break;
3948                                                 }
3949                                         case PGC_REAL:
3950                                                 {
3951                                                         struct config_real *conf = (struct config_real *) gconf;
3952                                                         double          newval = newvalue.realval;
3953
3954                                                         if (*conf->variable != newval)
3955                                                         {
3956                                                                 if (conf->assign_hook)
3957                                                                         if (!(*conf->assign_hook) (newval,
3958                                                                                                            true, PGC_S_OVERRIDE))
3959                                                                                 elog(LOG, "failed to commit %s as %g",
3960                                                                                          conf->gen.name, newval);
3961                                                                 *conf->variable = newval;
3962                                                                 changed = true;
3963                                                         }
3964                                                         break;
3965                                                 }
3966                                         case PGC_STRING:
3967                                                 {
3968                                                         struct config_string *conf = (struct config_string *) gconf;
3969                                                         char       *newval = newvalue.stringval;
3970
3971                                                         if (*conf->variable != newval)
3972                                                         {
3973                                                                 if (conf->assign_hook && newval)
3974                                                                 {
3975                                                                         const char *newstr;
3976
3977                                                                         newstr = (*conf->assign_hook) (newval, true,
3978                                                                                                                          PGC_S_OVERRIDE);
3979                                                                         if (newstr == NULL)
3980                                                                                 elog(LOG, "failed to commit %s as \"%s\"",
3981                                                                                          conf->gen.name, newval);
3982                                                                         else if (newstr != newval)
3983                                                                         {
3984                                                                                 /*
3985                                                                                  * If newval should now be freed,
3986                                                                                  * it'll be taken care of below.
3987                                                                                  *
3988                                                                                  * See notes in set_config_option
3989                                                                                  * about casting
3990                                                                                  */
3991                                                                                 newval = (char *) newstr;
3992                                                                         }
3993                                                                 }
3994
3995                                                                 set_string_field(conf, conf->variable, newval);
3996                                                                 changed = true;
3997                                                         }
3998
3999                                                         /*
4000                                                          * Release stacked values if not used anymore. We
4001                                                          * could use discard_stack_value() here, but since
4002                                                          * we have type-specific code anyway, might as
4003                                                          * well inline it.
4004                                                          */
4005                                                         set_string_field(conf, &stack->prior.stringval, NULL);
4006                                                         set_string_field(conf, &stack->masked.stringval, NULL);
4007                                                         break;
4008                                                 }
4009                                         case PGC_ENUM:
4010                                                 {
4011                                                         struct config_enum *conf = (struct config_enum *) gconf;
4012                                                         int newval = newvalue.enumval;
4013
4014                                                         if (*conf->variable != newval)
4015                                                         {
4016                                                                 if (conf->assign_hook)
4017                                                                         if (!(*conf->assign_hook) (newval,
4018                                                                                                                            true, PGC_S_OVERRIDE))
4019                                                                                 elog(LOG, "failed to commit %s as %s",
4020                                                                                          conf->gen.name,
4021                                                                                          config_enum_lookup_by_value(conf, newval));
4022                                                                 *conf->variable = newval;
4023                                                                 changed = true;
4024                                                         }
4025                                                         break;
4026                                                 }
4027                                 }
4028
4029                                 gconf->source = newsource;
4030                         }
4031
4032                         /* Finish popping the state stack */
4033                         gconf->stack = prev;
4034                         pfree(stack);
4035
4036                         /* Report new value if we changed it */
4037                         if (changed && (gconf->flags & GUC_REPORT))
4038                                 ReportGUCOption(gconf);
4039                 }                                               /* end of stack-popping loop */
4040
4041                 if (stack != NULL)
4042                         still_dirty = true;
4043         }
4044
4045         /* If there are no remaining stack entries, we can reset guc_dirty */
4046         guc_dirty = still_dirty;
4047
4048         /* Update nesting level */
4049         GUCNestLevel = nestLevel - 1;
4050 }
4051
4052
4053 /*
4054  * Start up automatic reporting of changes to variables marked GUC_REPORT.
4055  * This is executed at completion of backend startup.
4056  */
4057 void
4058 BeginReportingGUCOptions(void)
4059 {
4060         int                     i;
4061
4062         /*
4063          * Don't do anything unless talking to an interactive frontend of protocol
4064          * 3.0 or later.
4065          */
4066         if (whereToSendOutput != DestRemote ||
4067                 PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
4068                 return;
4069
4070         reporting_enabled = true;
4071
4072         /* Transmit initial values of interesting variables */
4073         for (i = 0; i < num_guc_variables; i++)
4074         {
4075                 struct config_generic *conf = guc_variables[i];
4076
4077                 if (conf->flags & GUC_REPORT)
4078                         ReportGUCOption(conf);
4079         }
4080 }
4081
4082 /*
4083  * ReportGUCOption: if appropriate, transmit option value to frontend
4084  */
4085 static void
4086 ReportGUCOption(struct config_generic * record)
4087 {
4088         if (reporting_enabled && (record->flags & GUC_REPORT))
4089         {
4090                 char       *val = _ShowOption(record, false);
4091                 StringInfoData msgbuf;
4092
4093                 pq_beginmessage(&msgbuf, 'S');
4094                 pq_sendstring(&msgbuf, record->name);
4095                 pq_sendstring(&msgbuf, val);
4096                 pq_endmessage(&msgbuf);
4097
4098                 pfree(val);
4099         }
4100 }
4101
4102 /*
4103  * Try to parse value as an integer.  The accepted formats are the
4104  * usual decimal, octal, or hexadecimal formats, optionally followed by
4105  * a unit name if "flags" indicates a unit is allowed.
4106  *
4107  * If the string parses okay, return true, else false.
4108  * If okay and result is not NULL, return the value in *result.
4109  * If not okay and hintmsg is not NULL, *hintmsg is set to a suitable
4110  *      HINT message, or NULL if no hint provided.
4111  */
4112 bool
4113 parse_int(const char *value, int *result, int flags, const char **hintmsg)
4114 {
4115         int64           val;
4116         char       *endptr;
4117
4118         /* To suppress compiler warnings, always set output params */
4119         if (result)
4120                 *result = 0;
4121         if (hintmsg)
4122                 *hintmsg = NULL;
4123
4124         /* We assume here that int64 is at least as wide as long */
4125         errno = 0;
4126         val = strtol(value, &endptr, 0);
4127
4128         if (endptr == value)
4129                 return false;                   /* no HINT for integer syntax error */
4130
4131         if (errno == ERANGE || val != (int64) ((int32) val))
4132         {
4133                 if (hintmsg)
4134                         *hintmsg = gettext_noop("Value exceeds integer range.");
4135                 return false;
4136         }
4137
4138         /* allow whitespace between integer and unit */
4139         while (isspace((unsigned char) *endptr))
4140                 endptr++;
4141
4142         /* Handle possible unit */
4143         if (*endptr != '\0')
4144         {
4145                 /*
4146                  * Note: the multiple-switch coding technique here is a bit tedious,
4147                  * but seems necessary to avoid intermediate-value overflows.
4148                  *
4149                  * If INT64_IS_BUSTED (ie, it's really int32) we will fail to detect
4150                  * overflow due to units conversion, but there are few enough such
4151                  * machines that it does not seem worth trying to be smarter.
4152                  */
4153                 if (flags & GUC_UNIT_MEMORY)
4154                 {
4155                         /* Set hint for use if no match or trailing garbage */
4156                         if (hintmsg)
4157                                 *hintmsg = gettext_noop("Valid units for this parameter are \"kB\", \"MB\", and \"GB\".");
4158
4159 #if BLCKSZ < 1024 || BLCKSZ > (1024*1024)
4160 #error BLCKSZ must be between 1KB and 1MB
4161 #endif
4162 #if XLOG_BLCKSZ < 1024 || XLOG_BLCKSZ > (1024*1024)
4163 #error XLOG_BLCKSZ must be between 1KB and 1MB
4164 #endif
4165
4166                         if (strncmp(endptr, "kB", 2) == 0)
4167                         {
4168                                 endptr += 2;
4169                                 switch (flags & GUC_UNIT_MEMORY)
4170                                 {
4171                                         case GUC_UNIT_BLOCKS:
4172                                                 val /= (BLCKSZ / 1024);
4173                                                 break;
4174                                         case GUC_UNIT_XBLOCKS:
4175                                                 val /= (XLOG_BLCKSZ / 1024);
4176                                                 break;
4177                                 }
4178                         }
4179                         else if (strncmp(endptr, "MB", 2) == 0)
4180                         {
4181                                 endptr += 2;
4182                                 switch (flags & GUC_UNIT_MEMORY)
4183                                 {
4184                                         case GUC_UNIT_KB:
4185                                                 val *= KB_PER_MB;
4186                                                 break;
4187                                         case GUC_UNIT_BLOCKS:
4188                                                 val *= KB_PER_MB / (BLCKSZ / 1024);
4189                                                 break;
4190                                         case GUC_UNIT_XBLOCKS:
4191                                                 val *= KB_PER_MB / (XLOG_BLCKSZ / 1024);
4192                                                 break;
4193                                 }
4194                         }
4195                         else if (strncmp(endptr, "GB", 2) == 0)
4196                         {
4197                                 endptr += 2;
4198                                 switch (flags & GUC_UNIT_MEMORY)
4199                                 {
4200                                         case GUC_UNIT_KB:
4201                                                 val *= KB_PER_GB;
4202                                                 break;
4203                                         case GUC_UNIT_BLOCKS:
4204                                                 val *= KB_PER_GB / (BLCKSZ / 1024);
4205                                                 break;
4206                                         case GUC_UNIT_XBLOCKS:
4207                                                 val *= KB_PER_GB / (XLOG_BLCKSZ / 1024);
4208                                                 break;
4209                                 }
4210                         }
4211                 }
4212                 else if (flags & GUC_UNIT_TIME)
4213                 {
4214                         /* Set hint for use if no match or trailing garbage */
4215                         if (hintmsg)
4216                                 *hintmsg = gettext_noop("Valid units for this parameter are \"ms\", \"s\", \"min\", \"h\", and \"d\".");
4217
4218                         if (strncmp(endptr, "ms", 2) == 0)
4219                         {
4220                                 endptr += 2;
4221                                 switch (flags & GUC_UNIT_TIME)
4222                                 {
4223                                         case GUC_UNIT_S:
4224                                                 val /= MS_PER_S;
4225                                                 break;
4226                                         case GUC_UNIT_MIN:
4227                                                 val /= MS_PER_MIN;
4228                                                 break;
4229                                 }
4230                         }
4231                         else if (strncmp(endptr, "s", 1) == 0)
4232                         {
4233                                 endptr += 1;
4234                                 switch (flags & GUC_UNIT_TIME)
4235                                 {
4236                                         case GUC_UNIT_MS:
4237                                                 val *= MS_PER_S;
4238                                                 break;
4239                                         case GUC_UNIT_MIN:
4240                                                 val /= S_PER_MIN;
4241                                                 break;
4242                                 }
4243                         }
4244                         else if (strncmp(endptr, "min", 3) == 0)
4245                         {
4246                                 endptr += 3;
4247                                 switch (flags & GUC_UNIT_TIME)
4248                                 {
4249                                         case GUC_UNIT_MS:
4250                                                 val *= MS_PER_MIN;
4251                                                 break;
4252                                         case GUC_UNIT_S:
4253                                                 val *= S_PER_MIN;
4254                                                 break;
4255                                 }
4256                         }
4257                         else if (strncmp(endptr, "h", 1) == 0)
4258                         {
4259                                 endptr += 1;
4260                                 switch (flags & GUC_UNIT_TIME)
4261                                 {
4262                                         case GUC_UNIT_MS:
4263                                                 val *= MS_PER_H;
4264                                                 break;
4265                                         case GUC_UNIT_S:
4266                                                 val *= S_PER_H;
4267                                                 break;
4268                                         case GUC_UNIT_MIN:
4269                                                 val *= MIN_PER_H;
4270                                                 break;
4271                                 }
4272                         }
4273                         else if (strncmp(endptr, "d", 1) == 0)
4274                         {
4275                                 endptr += 1;
4276                                 switch (flags & GUC_UNIT_TIME)
4277                                 {
4278                                         case GUC_UNIT_MS:
4279                                                 val *= MS_PER_D;
4280                                                 break;
4281                                         case GUC_UNIT_S:
4282                                                 val *= S_PER_D;
4283                                                 break;
4284                                         case GUC_UNIT_MIN:
4285                                                 val *= MIN_PER_D;
4286                                                 break;
4287                                 }
4288                         }
4289                 }
4290
4291                 /* allow whitespace after unit */
4292                 while (isspace((unsigned char) *endptr))
4293                         endptr++;
4294
4295                 if (*endptr != '\0')
4296                         return false;           /* appropriate hint, if any, already set */
4297
4298                 /* Check for overflow due to units conversion */
4299                 if (val != (int64) ((int32) val))
4300                 {
4301                         if (hintmsg)
4302                                 *hintmsg = gettext_noop("Value exceeds integer range.");
4303                         return false;
4304                 }
4305         }
4306
4307         if (result)
4308                 *result = (int) val;
4309         return true;
4310 }
4311
4312
4313
4314 /*
4315  * Try to parse value as a floating point number in the usual format.
4316  * If the string parses okay, return true, else false.
4317  * If okay and result is not NULL, return the value in *result.
4318  */
4319 bool
4320 parse_real(const char *value, double *result)
4321 {
4322         double          val;
4323         char       *endptr;
4324
4325         if (result)
4326                 *result = 0;                    /* suppress compiler warning */
4327
4328         errno = 0;
4329         val = strtod(value, &endptr);
4330         if (endptr == value || errno == ERANGE)
4331                 return false;
4332
4333         /* allow whitespace after number */
4334         while (isspace((unsigned char) *endptr))
4335                 endptr++;
4336         if (*endptr != '\0')
4337                 return false;
4338
4339         if (result)
4340                 *result = val;
4341         return true;
4342 }
4343
4344
4345 /*
4346  * Lookup the name for an enum option with the selected value.
4347  * Should only ever be called with known-valid values, so throws
4348  * an elog(ERROR) if the enum option is not found.
4349  *
4350  * The returned string is a pointer to static data and not
4351  * allocated for modification.
4352  */
4353 const char *
4354 config_enum_lookup_by_value(struct config_enum *record, int val)
4355 {
4356         const struct config_enum_entry *entry;
4357
4358         for (entry = record->options; entry && entry->name; entry++)
4359         {
4360                 if (entry->val == val)
4361                         return entry->name;
4362         }
4363
4364         elog(ERROR, "could not find enum option %d for %s",
4365                  val, record->gen.name);
4366         return NULL;            /* silence compiler */
4367 }
4368
4369
4370 /*
4371  * Lookup the value for an enum option with the selected name
4372  * (case-insensitive).
4373  * If the enum option is found, sets the retval value and returns
4374  * true. If it's not found, return FALSE and retval is set to 0.
4375  */
4376 bool
4377 config_enum_lookup_by_name(struct config_enum *record, const char *value,
4378                                                    int *retval)
4379 {
4380         const struct config_enum_entry *entry;
4381
4382         for (entry = record->options; entry && entry->name; entry++)
4383         {
4384                 if (pg_strcasecmp(value, entry->name) == 0)
4385                 {
4386                         *retval = entry->val;
4387                         return TRUE;
4388                 }
4389         }
4390
4391         *retval = 0;
4392         return FALSE;
4393 }
4394
4395
4396 /*
4397  * Return a list of all available options for an enum, excluding
4398  * hidden ones, separated by the given separator.
4399  * If prefix is non-NULL, it is added before the first enum value.
4400  * If suffix is non-NULL, it is added to the end of the string.
4401  */
4402 static char *
4403 config_enum_get_options(struct config_enum *record, const char *prefix,
4404                                                 const char *suffix, const char *separator)
4405 {
4406         const struct config_enum_entry *entry;
4407         StringInfoData  retstr;
4408         int                     seplen;
4409
4410         initStringInfo(&retstr);
4411         appendStringInfoString(&retstr, prefix);
4412
4413         seplen = strlen(separator);
4414         for (entry = record->options; entry && entry->name; entry++)
4415         {
4416                 if (!entry->hidden)
4417                 {
4418                         appendStringInfoString(&retstr, entry->name);
4419                         appendBinaryStringInfo(&retstr, separator, seplen);
4420                 }
4421         }
4422
4423         /*
4424          * All the entries may have been hidden, leaving the string empty
4425          * if no prefix was given. This indicates a broken GUC setup, since
4426          * there is no use for an enum without any values, so we just check
4427          * to make sure we don't write to invalid memory instead of actually
4428          * trying to do something smart with it.
4429          */
4430         if (retstr.len >= seplen)
4431         {
4432                 /* Replace final separator */
4433                 retstr.data[retstr.len - seplen] = '\0';
4434                 retstr.len -= seplen;
4435         }
4436
4437         appendStringInfoString(&retstr, suffix);
4438
4439         return retstr.data;
4440 }
4441
4442 /*
4443  * Call a GucStringAssignHook function, being careful to free the
4444  * "newval" string if the hook ereports.
4445  *
4446  * This is split out of set_config_option just to avoid the "volatile"
4447  * qualifiers that would otherwise have to be plastered all over.
4448  */
4449 static const char *
4450 call_string_assign_hook(GucStringAssignHook assign_hook,
4451                                                 char *newval, bool doit, GucSource source)
4452 {
4453         const char *result;
4454
4455         PG_TRY();
4456         {
4457                 result = (*assign_hook) (newval, doit, source);
4458         }
4459         PG_CATCH();
4460         {
4461                 free(newval);
4462                 PG_RE_THROW();
4463         }
4464         PG_END_TRY();
4465
4466         return result;
4467 }
4468
4469
4470 /*
4471  * Sets option `name' to given value. The value should be a string
4472  * which is going to be parsed and converted to the appropriate data
4473  * type.  The context and source parameters indicate in which context this
4474  * function is being called so it can apply the access restrictions
4475  * properly.
4476  *
4477  * If value is NULL, set the option to its default value (normally the
4478  * reset_val, but if source == PGC_S_DEFAULT we instead use the boot_val).
4479  *
4480  * action indicates whether to set the value globally in the session, locally
4481  * to the current top transaction, or just for the duration of a function call.
4482  *
4483  * If changeVal is false then don't really set the option but do all
4484  * the checks to see if it would work.
4485  *
4486  * If there is an error (non-existing option, invalid value) then an
4487  * ereport(ERROR) is thrown *unless* this is called in a context where we
4488  * don't want to ereport (currently, startup or SIGHUP config file reread).
4489  * In that case we write a suitable error message via ereport(LOG) and
4490  * return false. This is working around the deficiencies in the ereport
4491  * mechanism, so don't blame me.  In all other cases, the function
4492  * returns true, including cases where the input is valid but we chose
4493  * not to apply it because of context or source-priority considerations.
4494  *
4495  * See also SetConfigOption for an external interface.
4496  */
4497 bool
4498 set_config_option(const char *name, const char *value,
4499                                   GucContext context, GucSource source,
4500                                   GucAction action, bool changeVal)
4501 {
4502         struct config_generic *record;
4503         int                     elevel;
4504         bool            makeDefault;
4505
4506         if (context == PGC_SIGHUP || source == PGC_S_DEFAULT)
4507         {
4508                 /*
4509                  * To avoid cluttering the log, only the postmaster bleats loudly
4510                  * about problems with the config file.
4511                  */
4512                 elevel = IsUnderPostmaster ? DEBUG3 : LOG;
4513         }
4514         else if (source == PGC_S_DATABASE || source == PGC_S_USER)
4515                 elevel = WARNING;
4516         else
4517                 elevel = ERROR;
4518
4519         record = find_option(name, true, elevel);
4520         if (record == NULL)
4521         {
4522                 ereport(elevel,
4523                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
4524                            errmsg("unrecognized configuration parameter \"%s\"", name)));
4525                 return false;
4526         }
4527
4528         /*
4529          * If source is postgresql.conf, mark the found record with
4530          * GUC_IS_IN_FILE. This is for the convenience of ProcessConfigFile.  Note
4531          * that we do it even if changeVal is false, since ProcessConfigFile wants
4532          * the marking to occur during its testing pass.
4533          */
4534         if (source == PGC_S_FILE)
4535                 record->status |= GUC_IS_IN_FILE;
4536
4537         /*
4538          * Check if the option can be set at this time. See guc.h for the precise
4539          * rules. Note that we don't want to throw errors if we're in the SIGHUP
4540          * context. In that case we just ignore the attempt and return true.
4541          */
4542         switch (record->context)
4543         {
4544                 case PGC_INTERNAL:
4545                         if (context == PGC_SIGHUP)
4546                                 return true;
4547                         if (context != PGC_INTERNAL)
4548                         {
4549                                 ereport(elevel,
4550                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4551                                                  errmsg("parameter \"%s\" cannot be changed",
4552                                                                 name)));
4553                                 return false;
4554                         }
4555                         break;
4556                 case PGC_POSTMASTER:
4557                         if (context == PGC_SIGHUP)
4558                         {
4559                                 /*
4560                                  * We are reading a PGC_POSTMASTER var from postgresql.conf.
4561                                  * We can't change the setting, so give a warning if the DBA
4562                                  * tries to change it.  (Throwing an error would be more
4563                                  * consistent, but seems overly rigid.)
4564                                  */
4565                                 if (changeVal && !is_newvalue_equal(record, value))
4566                                         ereport(elevel,
4567                                                         (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4568                                                          errmsg("attempted change of parameter \"%s\" ignored",
4569                                                                         name),
4570                                                          errdetail("This parameter cannot be changed after server start.")));
4571                                 return true;
4572                         }
4573                         if (context != PGC_POSTMASTER)
4574                         {
4575                                 ereport(elevel,
4576                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4577                                                  errmsg("attempted change of parameter \"%s\" ignored",
4578                                                                 name),
4579                                                  errdetail("This parameter cannot be changed after server start.")));
4580                                 return false;
4581                         }
4582                         break;
4583                 case PGC_SIGHUP:
4584                         if (context != PGC_SIGHUP && context != PGC_POSTMASTER)
4585                         {
4586                                 ereport(elevel,
4587                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4588                                                  errmsg("parameter \"%s\" cannot be changed now",
4589                                                                 name)));
4590                                 return false;
4591                         }
4592
4593                         /*
4594                          * Hmm, the idea of the SIGHUP context is "ought to be global, but
4595                          * can be changed after postmaster start". But there's nothing
4596                          * that prevents a crafty administrator from sending SIGHUP
4597                          * signals to individual backends only.
4598                          */
4599                         break;
4600                 case PGC_BACKEND:
4601                         if (context == PGC_SIGHUP)
4602                         {
4603                                 /*
4604                                  * If a PGC_BACKEND parameter is changed in the config file,
4605                                  * we want to accept the new value in the postmaster (whence
4606                                  * it will propagate to subsequently-started backends), but
4607                                  * ignore it in existing backends.      This is a tad klugy, but
4608                                  * necessary because we don't re-read the config file during
4609                                  * backend start.
4610                                  */
4611                                 if (IsUnderPostmaster)
4612                                         return true;
4613                         }
4614                         else if (context != PGC_BACKEND && context != PGC_POSTMASTER)
4615                         {
4616                                 ereport(elevel,
4617                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4618                                                  errmsg("parameter \"%s\" cannot be set after connection start",
4619                                                                 name)));
4620                                 return false;
4621                         }
4622                         break;
4623                 case PGC_SUSET:
4624                         if (context == PGC_USERSET || context == PGC_BACKEND)
4625                         {
4626                                 ereport(elevel,
4627                                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
4628                                                  errmsg("permission denied to set parameter \"%s\"",
4629                                                                 name)));
4630                                 return false;
4631                         }
4632                         break;
4633                 case PGC_USERSET:
4634                         /* always okay */
4635                         break;
4636         }
4637
4638         /*
4639          * Should we set reset/stacked values?  (If so, the behavior is not
4640          * transactional.)      This is done either when we get a default value from
4641          * the database's/user's/client's default settings or when we reset a
4642          * value to its default.
4643          */
4644         makeDefault = changeVal && (source <= PGC_S_OVERRIDE) &&
4645                 ((value != NULL) || source == PGC_S_DEFAULT);
4646
4647         /*
4648          * Ignore attempted set if overridden by previously processed setting.
4649          * However, if changeVal is false then plow ahead anyway since we are
4650          * trying to find out if the value is potentially good, not actually use
4651          * it. Also keep going if makeDefault is true, since we may want to set
4652          * the reset/stacked values even if we can't set the variable itself.
4653          */
4654         if (record->source > source)
4655         {
4656                 if (changeVal && !makeDefault)
4657                 {
4658                         elog(DEBUG3, "\"%s\": setting ignored because previous source is higher priority",
4659                                  name);
4660                         return true;
4661                 }
4662                 changeVal = false;
4663         }
4664
4665         /*
4666          * Evaluate value and set variable.
4667          */
4668         switch (record->vartype)
4669         {
4670                 case PGC_BOOL:
4671                         {
4672                                 struct config_bool *conf = (struct config_bool *) record;
4673                                 bool            newval;
4674
4675                                 if (value)
4676                                 {
4677                                         if (!parse_bool(value, &newval))
4678                                         {
4679                                                 ereport(elevel,
4680                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4681                                                   errmsg("parameter \"%s\" requires a Boolean value",
4682                                                                  name)));
4683                                                 return false;
4684                                         }
4685                                 }
4686                                 else if (source == PGC_S_DEFAULT)
4687                                         newval = conf->boot_val;
4688                                 else
4689                                 {
4690                                         newval = conf->reset_val;
4691                                         source = conf->gen.reset_source;
4692                                 }
4693
4694                                 /* Save old value to support transaction abort */
4695                                 if (changeVal && !makeDefault)
4696                                         push_old_value(&conf->gen, action);
4697
4698                                 if (conf->assign_hook)
4699                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4700                                         {
4701                                                 ereport(elevel,
4702                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4703                                                          errmsg("invalid value for parameter \"%s\": %d",
4704                                                                         name, (int) newval)));
4705                                                 return false;
4706                                         }
4707
4708                                 if (changeVal)
4709                                 {
4710                                         *conf->variable = newval;
4711                                         conf->gen.source = source;
4712                                 }
4713                                 if (makeDefault)
4714                                 {
4715                                         GucStack   *stack;
4716
4717                                         if (conf->gen.reset_source <= source)
4718                                         {
4719                                                 conf->reset_val = newval;
4720                                                 conf->gen.reset_source = source;
4721                                         }
4722                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4723                                         {
4724                                                 if (stack->source <= source)
4725                                                 {
4726                                                         stack->prior.boolval = newval;
4727                                                         stack->source = source;
4728                                                 }
4729                                         }
4730                                 }
4731                                 break;
4732                         }
4733
4734                 case PGC_INT:
4735                         {
4736                                 struct config_int *conf = (struct config_int *) record;
4737                                 int                     newval;
4738
4739                                 if (value)
4740                                 {
4741                                         const char *hintmsg;
4742
4743                                         if (!parse_int(value, &newval, conf->gen.flags, &hintmsg))
4744                                         {
4745                                                 ereport(elevel,
4746                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4747                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
4748                                                                 name, value),
4749                                                                  hintmsg ? errhint("%s", _(hintmsg)) : 0));
4750                                                 return false;
4751                                         }
4752                                         if (newval < conf->min || newval > conf->max)
4753                                         {
4754                                                 ereport(elevel,
4755                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4756                                                                  errmsg("%d is outside the valid range for parameter \"%s\" (%d .. %d)",
4757                                                                                 newval, name, conf->min, conf->max)));
4758                                                 return false;
4759                                         }
4760                                 }
4761                                 else if (source == PGC_S_DEFAULT)
4762                                         newval = conf->boot_val;
4763                                 else
4764                                 {
4765                                         newval = conf->reset_val;
4766                                         source = conf->gen.reset_source;
4767                                 }
4768
4769                                 /* Save old value to support transaction abort */
4770                                 if (changeVal && !makeDefault)
4771                                         push_old_value(&conf->gen, action);
4772
4773                                 if (conf->assign_hook)
4774                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4775                                         {
4776                                                 ereport(elevel,
4777                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4778                                                          errmsg("invalid value for parameter \"%s\": %d",
4779                                                                         name, newval)));
4780                                                 return false;
4781                                         }
4782
4783                                 if (changeVal)
4784                                 {
4785                                         *conf->variable = newval;
4786                                         conf->gen.source = source;
4787                                 }
4788                                 if (makeDefault)
4789                                 {
4790                                         GucStack   *stack;
4791
4792                                         if (conf->gen.reset_source <= source)
4793                                         {
4794                                                 conf->reset_val = newval;
4795                                                 conf->gen.reset_source = source;
4796                                         }
4797                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4798                                         {
4799                                                 if (stack->source <= source)
4800                                                 {
4801                                                         stack->prior.intval = newval;
4802                                                         stack->source = source;
4803                                                 }
4804                                         }
4805                                 }
4806                                 break;
4807                         }
4808
4809                 case PGC_REAL:
4810                         {
4811                                 struct config_real *conf = (struct config_real *) record;
4812                                 double          newval;
4813
4814                                 if (value)
4815                                 {
4816                                         if (!parse_real(value, &newval))
4817                                         {
4818                                                 ereport(elevel,
4819                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4820                                                   errmsg("parameter \"%s\" requires a numeric value",
4821                                                                  name)));
4822                                                 return false;
4823                                         }
4824                                         if (newval < conf->min || newval > conf->max)
4825                                         {
4826                                                 ereport(elevel,
4827                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4828                                                                  errmsg("%g is outside the valid range for parameter \"%s\" (%g .. %g)",
4829                                                                                 newval, name, conf->min, conf->max)));
4830                                                 return false;
4831                                         }
4832                                 }
4833                                 else if (source == PGC_S_DEFAULT)
4834                                         newval = conf->boot_val;
4835                                 else
4836                                 {
4837                                         newval = conf->reset_val;
4838                                         source = conf->gen.reset_source;
4839                                 }
4840
4841                                 /* Save old value to support transaction abort */
4842                                 if (changeVal && !makeDefault)
4843                                         push_old_value(&conf->gen, action);
4844
4845                                 if (conf->assign_hook)
4846                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4847                                         {
4848                                                 ereport(elevel,
4849                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4850                                                          errmsg("invalid value for parameter \"%s\": %g",
4851                                                                         name, newval)));
4852                                                 return false;
4853                                         }
4854
4855                                 if (changeVal)
4856                                 {
4857                                         *conf->variable = newval;
4858                                         conf->gen.source = source;
4859                                 }
4860                                 if (makeDefault)
4861                                 {
4862                                         GucStack   *stack;
4863
4864                                         if (conf->gen.reset_source <= source)
4865                                         {
4866                                                 conf->reset_val = newval;
4867                                                 conf->gen.reset_source = source;
4868                                         }
4869                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4870                                         {
4871                                                 if (stack->source <= source)
4872                                                 {
4873                                                         stack->prior.realval = newval;
4874                                                         stack->source = source;
4875                                                 }
4876                                         }
4877                                 }
4878                                 break;
4879                         }
4880
4881                 case PGC_STRING:
4882                         {
4883                                 struct config_string *conf = (struct config_string *) record;
4884                                 char       *newval;
4885
4886                                 if (value)
4887                                 {
4888                                         newval = guc_strdup(elevel, value);
4889                                         if (newval == NULL)
4890                                                 return false;
4891
4892                                         /*
4893                                          * The only sort of "parsing" check we need to do is apply
4894                                          * truncation if GUC_IS_NAME.
4895                                          */
4896                                         if (conf->gen.flags & GUC_IS_NAME)
4897                                                 truncate_identifier(newval, strlen(newval), true);
4898                                 }
4899                                 else if (source == PGC_S_DEFAULT)
4900                                 {
4901                                         if (conf->boot_val == NULL)
4902                                                 newval = NULL;
4903                                         else
4904                                         {
4905                                                 newval = guc_strdup(elevel, conf->boot_val);
4906                                                 if (newval == NULL)
4907                                                         return false;
4908                                         }
4909                                 }
4910                                 else
4911                                 {
4912                                         /*
4913                                          * We could possibly avoid strdup here, but easier to make
4914                                          * this case work the same as the normal assignment case;
4915                                          * note the possible free of newval below.
4916                                          */
4917                                         if (conf->reset_val == NULL)
4918                                                 newval = NULL;
4919                                         else
4920                                         {
4921                                                 newval = guc_strdup(elevel, conf->reset_val);
4922                                                 if (newval == NULL)
4923                                                         return false;
4924                                         }
4925                                         source = conf->gen.reset_source;
4926                                 }
4927
4928                                 /* Save old value to support transaction abort */
4929                                 if (changeVal && !makeDefault)
4930                                         push_old_value(&conf->gen, action);
4931
4932                                 if (conf->assign_hook && newval)
4933                                 {
4934                                         const char *hookresult;
4935
4936                                         /*
4937                                          * If the hook ereports, we have to make sure we free
4938                                          * newval, else it will be a permanent memory leak.
4939                                          */
4940                                         hookresult = call_string_assign_hook(conf->assign_hook,
4941                                                                                                                  newval,
4942                                                                                                                  changeVal,
4943                                                                                                                  source);
4944                                         if (hookresult == NULL)
4945                                         {
4946                                                 free(newval);
4947                                                 ereport(elevel,
4948                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4949                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
4950                                                                 name, value ? value : "")));
4951                                                 return false;
4952                                         }
4953                                         else if (hookresult != newval)
4954                                         {
4955                                                 free(newval);
4956
4957                                                 /*
4958                                                  * Having to cast away const here is annoying, but the
4959                                                  * alternative is to declare assign_hooks as returning
4960                                                  * char*, which would mean they'd have to cast away
4961                                                  * const, or as both taking and returning char*, which
4962                                                  * doesn't seem attractive either --- we don't want
4963                                                  * them to scribble on the passed str.
4964                                                  */
4965                                                 newval = (char *) hookresult;
4966                                         }
4967                                 }
4968
4969                                 if (changeVal)
4970                                 {
4971                                         set_string_field(conf, conf->variable, newval);
4972                                         conf->gen.source = source;
4973                                 }
4974                                 if (makeDefault)
4975                                 {
4976                                         GucStack   *stack;
4977
4978                                         if (conf->gen.reset_source <= source)
4979                                         {
4980                                                 set_string_field(conf, &conf->reset_val, newval);
4981                                                 conf->gen.reset_source = source;
4982                                         }
4983                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4984                                         {
4985                                                 if (stack->source <= source)
4986                                                 {
4987                                                         set_string_field(conf, &stack->prior.stringval,
4988                                                                                          newval);
4989                                                         stack->source = source;
4990                                                 }
4991                                         }
4992                                 }
4993                                 /* Perhaps we didn't install newval anywhere */
4994                                 if (newval && !string_field_used(conf, newval))
4995                                         free(newval);
4996                                 break;
4997                         }
4998                 case PGC_ENUM:
4999                         {
5000                                 struct config_enum *conf = (struct config_enum *) record;
5001                                 int                     newval;
5002
5003                                 if (value)
5004                                 {
5005                                         if (!config_enum_lookup_by_name(conf, value, &newval))
5006                                         {
5007                                                 char *hintmsg;
5008
5009                                                 hintmsg = config_enum_get_options(conf,
5010                                                                                                                   "Available values: ",
5011                                                                                                                   ".", ", ");
5012
5013                                                 ereport(elevel,
5014                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5015                                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
5016                                                                                 name, value),
5017                                                                  hintmsg ? errhint("%s", _(hintmsg)) : 0));
5018
5019                                                 if (hintmsg)
5020                                                         pfree(hintmsg);
5021                                                 return false;
5022                                         }
5023                                 }
5024                                 else if (source == PGC_S_DEFAULT)
5025                                         newval = conf->boot_val;
5026                                 else
5027                                 {
5028                                         newval = conf->reset_val;
5029                                         source = conf->gen.reset_source;
5030                                 }
5031
5032                                 /* Save old value to support transaction abort */
5033                                 if (changeVal && !makeDefault)
5034                                         push_old_value(&conf->gen, action);
5035
5036                                 if (conf->assign_hook)
5037                                         if (!(*conf->assign_hook) (newval, changeVal, source))
5038                                         {
5039                                                 ereport(elevel,
5040                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5041                                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
5042                                                                                 name,
5043                                                                                 config_enum_lookup_by_value(conf, newval))));
5044                                                 return false;
5045                                         }
5046
5047                                 if (changeVal)
5048                                 {
5049                                         *conf->variable = newval;
5050                                         conf->gen.source = source;
5051                                 }
5052                                 if (makeDefault)
5053                                 {
5054                                         GucStack   *stack;
5055
5056                                         if (conf->gen.reset_source <= source)
5057                                         {
5058                                                 conf->reset_val = newval;
5059                                                 conf->gen.reset_source = source;
5060                                         }
5061                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
5062                                         {
5063                                                 if (stack->source <= source)
5064                                                 {
5065                                                         stack->prior.enumval = newval;
5066                                                         stack->source = source;
5067                                                 }
5068                                         }
5069                                 }
5070                                 break;
5071                         }
5072         }
5073
5074         if (changeVal && (record->flags & GUC_REPORT))
5075                 ReportGUCOption(record);
5076
5077         return true;
5078 }
5079
5080
5081 /*
5082  * Set the fields for source file and line number the setting came from.
5083  */
5084 static void
5085 set_config_sourcefile(const char *name, char *sourcefile, int sourceline)
5086 {
5087         struct config_generic *record;
5088         int                     elevel;
5089
5090         /*
5091          * To avoid cluttering the log, only the postmaster bleats loudly
5092          * about problems with the config file.
5093          */
5094         elevel = IsUnderPostmaster ? DEBUG3 : LOG;
5095
5096         record = find_option(name, true, elevel);
5097         /* should not happen */
5098         if (record == NULL)
5099                 elog(ERROR, "unrecognized configuration parameter \"%s\"", name);
5100
5101         sourcefile = guc_strdup(elevel, sourcefile);
5102         if (record->sourcefile)
5103                 free(record->sourcefile);
5104         record->sourcefile = sourcefile;
5105         record->sourceline = sourceline;
5106 }
5107
5108 /*
5109  * Set a config option to the given value. See also set_config_option,
5110  * this is just the wrapper to be called from outside GUC.      NB: this
5111  * is used only for non-transactional operations.
5112  *
5113  * Note: there is no support here for setting source file/line, as it
5114  * is currently not needed.
5115  */
5116 void
5117 SetConfigOption(const char *name, const char *value,
5118                                 GucContext context, GucSource source)
5119 {
5120         (void) set_config_option(name, value, context, source,
5121                                                          GUC_ACTION_SET, true);
5122 }
5123
5124
5125
5126 /*
5127  * Fetch the current value of the option `name'. If the option doesn't exist,
5128  * throw an ereport and don't return.
5129  *
5130  * The string is *not* allocated for modification and is really only
5131  * valid until the next call to configuration related functions.
5132  */
5133 const char *
5134 GetConfigOption(const char *name)
5135 {
5136         struct config_generic *record;
5137         static char buffer[256];
5138
5139         record = find_option(name, false, ERROR);
5140         if (record == NULL)
5141                 ereport(ERROR,
5142                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5143                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5144         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
5145                 ereport(ERROR,
5146                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5147                                  errmsg("must be superuser to examine \"%s\"", name)));
5148
5149         switch (record->vartype)
5150         {
5151                 case PGC_BOOL:
5152                         return *((struct config_bool *) record)->variable ? "on" : "off";
5153
5154                 case PGC_INT:
5155                         snprintf(buffer, sizeof(buffer), "%d",
5156                                          *((struct config_int *) record)->variable);
5157                         return buffer;
5158
5159                 case PGC_REAL:
5160                         snprintf(buffer, sizeof(buffer), "%g",
5161                                          *((struct config_real *) record)->variable);
5162                         return buffer;
5163
5164                 case PGC_STRING:
5165                         return *((struct config_string *) record)->variable;
5166
5167                 case PGC_ENUM:
5168                         return config_enum_lookup_by_value((struct config_enum *) record,
5169                                                                                         *((struct config_enum *) record)->variable);
5170         }
5171         return NULL;
5172 }
5173
5174 /*
5175  * Get the RESET value associated with the given option.
5176  *
5177  * Note: this is not re-entrant, due to use of static result buffer;
5178  * not to mention that a string variable could have its reset_val changed.
5179  * Beware of assuming the result value is good for very long.
5180  */
5181 const char *
5182 GetConfigOptionResetString(const char *name)
5183 {
5184         struct config_generic *record;
5185         static char buffer[256];
5186
5187         record = find_option(name, false, ERROR);
5188         if (record == NULL)
5189                 ereport(ERROR,
5190                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5191                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5192         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
5193                 ereport(ERROR,
5194                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5195                                  errmsg("must be superuser to examine \"%s\"", name)));
5196
5197         switch (record->vartype)
5198         {
5199                 case PGC_BOOL:
5200                         return ((struct config_bool *) record)->reset_val ? "on" : "off";
5201
5202                 case PGC_INT:
5203                         snprintf(buffer, sizeof(buffer), "%d",
5204                                          ((struct config_int *) record)->reset_val);
5205                         return buffer;
5206
5207                 case PGC_REAL:
5208                         snprintf(buffer, sizeof(buffer), "%g",
5209                                          ((struct config_real *) record)->reset_val);
5210                         return buffer;
5211
5212                 case PGC_STRING:
5213                         return ((struct config_string *) record)->reset_val;
5214
5215                 case PGC_ENUM:
5216                         return config_enum_lookup_by_value((struct config_enum *) record,
5217                                                                                     ((struct config_enum *) record)->reset_val);
5218         }
5219         return NULL;
5220 }
5221
5222 /*
5223  * Detect whether the given configuration option can only be set by
5224  * a superuser.
5225  */
5226 bool
5227 IsSuperuserConfigOption(const char *name)
5228 {
5229         struct config_generic *record;
5230
5231         record = find_option(name, false, ERROR);
5232         /* On an unrecognized name, don't error, just return false. */
5233         if (record == NULL)
5234                 return false;
5235         return (record->context == PGC_SUSET);
5236 }
5237
5238
5239 /*
5240  * GUC_complaint_elevel
5241  *              Get the ereport error level to use in an assign_hook's error report.
5242  *
5243  * This should be used by assign hooks that want to emit a custom error
5244  * report (in addition to the generic "invalid value for option FOO" that
5245  * guc.c will provide).  Note that the result might be ERROR or a lower
5246  * level, so the caller must be prepared for control to return from ereport,
5247  * or not.  If control does return, return false/NULL from the hook function.
5248  *
5249  * At some point it'd be nice to replace this with a mechanism that allows
5250  * the custom message to become the DETAIL line of guc.c's generic message.
5251  */
5252 int
5253 GUC_complaint_elevel(GucSource source)
5254 {
5255         int                     elevel;
5256
5257         if (source == PGC_S_FILE)
5258         {
5259                 /*
5260                  * To avoid cluttering the log, only the postmaster bleats loudly
5261                  * about problems with the config file.
5262                  */
5263                 elevel = IsUnderPostmaster ? DEBUG3 : LOG;
5264         }
5265         else if (source == PGC_S_OVERRIDE)
5266         {
5267                 /*
5268                  * If we're a postmaster child, this is probably "undo" during
5269                  * transaction abort, so we don't want to clutter the log.  There's
5270                  * a small chance of a real problem with an OVERRIDE setting,
5271                  * though, so suppressing the message entirely wouldn't be desirable.
5272                  */
5273                 elevel = IsUnderPostmaster ? DEBUG5 : LOG;
5274         }
5275         else if (source < PGC_S_INTERACTIVE)
5276                 elevel = LOG;
5277         else
5278                 elevel = ERROR;
5279
5280         return elevel;
5281 }
5282
5283
5284 /*
5285  * flatten_set_variable_args
5286  *              Given a parsenode List as emitted by the grammar for SET,
5287  *              convert to the flat string representation used by GUC.
5288  *
5289  * We need to be told the name of the variable the args are for, because
5290  * the flattening rules vary (ugh).
5291  *
5292  * The result is NULL if args is NIL (ie, SET ... TO DEFAULT), otherwise
5293  * a palloc'd string.
5294  */
5295 static char *
5296 flatten_set_variable_args(const char *name, List *args)
5297 {
5298         struct config_generic *record;
5299         int                     flags;
5300         StringInfoData buf;
5301         ListCell   *l;
5302
5303         /* Fast path if just DEFAULT */
5304         if (args == NIL)
5305                 return NULL;
5306
5307         /* Else get flags for the variable */
5308         record = find_option(name, true, ERROR);
5309         if (record == NULL)
5310                 ereport(ERROR,
5311                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5312                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5313
5314         flags = record->flags;
5315
5316         /* Complain if list input and non-list variable */
5317         if ((flags & GUC_LIST_INPUT) == 0 &&
5318                 list_length(args) != 1)
5319                 ereport(ERROR,
5320                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5321                                  errmsg("SET %s takes only one argument", name)));
5322
5323         initStringInfo(&buf);
5324
5325         /*
5326          * Each list member may be a plain A_Const node, or an A_Const within a
5327          * TypeCast; the latter case is supported only for ConstInterval
5328          * arguments (for SET TIME ZONE).
5329          */
5330         foreach(l, args)
5331         {
5332                 Node       *arg = (Node *) lfirst(l);
5333                 char       *val;
5334                 TypeName   *typename = NULL;
5335                 A_Const    *con;
5336
5337                 if (l != list_head(args))
5338                         appendStringInfo(&buf, ", ");
5339
5340                 if (IsA(arg, TypeCast))
5341                 {
5342                         TypeCast *tc = (TypeCast *) arg;
5343
5344                         arg = tc->arg;
5345                         typename = tc->typename;
5346                 }
5347
5348                 if (!IsA(arg, A_Const))
5349                         elog(ERROR, "unrecognized node type: %d", (int) nodeTag(arg));
5350                 con = (A_Const *) arg;
5351
5352                 switch (nodeTag(&con->val))
5353                 {
5354                         case T_Integer:
5355                                 appendStringInfo(&buf, "%ld", intVal(&con->val));
5356                                 break;
5357                         case T_Float:
5358                                 /* represented as a string, so just copy it */
5359                                 appendStringInfoString(&buf, strVal(&con->val));
5360                                 break;
5361                         case T_String:
5362                                 val = strVal(&con->val);
5363                                 if (typename != NULL)
5364                                 {
5365                                         /*
5366                                          * Must be a ConstInterval argument for TIME ZONE. Coerce
5367                                          * to interval and back to normalize the value and account
5368                                          * for any typmod.
5369                                          */
5370                                         Oid                     typoid;
5371                                         int32           typmod;
5372                                         Datum           interval;
5373                                         char       *intervalout;
5374
5375                                         typoid = typenameTypeId(NULL, typename, &typmod);
5376                                         Assert(typoid == INTERVALOID);
5377
5378                                         interval =
5379                                                 DirectFunctionCall3(interval_in,
5380                                                                                         CStringGetDatum(val),
5381                                                                                         ObjectIdGetDatum(InvalidOid),
5382                                                                                         Int32GetDatum(typmod));
5383
5384                                         intervalout =
5385                                                 DatumGetCString(DirectFunctionCall1(interval_out,
5386                                                                                                                         interval));
5387                                         appendStringInfo(&buf, "INTERVAL '%s'", intervalout);
5388                                 }
5389                                 else
5390                                 {
5391                                         /*
5392                                          * Plain string literal or identifier.  For quote mode,
5393                                          * quote it if it's not a vanilla identifier.
5394                                          */
5395                                         if (flags & GUC_LIST_QUOTE)
5396                                                 appendStringInfoString(&buf, quote_identifier(val));
5397                                         else
5398                                                 appendStringInfoString(&buf, val);
5399                                 }
5400                                 break;
5401                         default:
5402                                 elog(ERROR, "unrecognized node type: %d",
5403                                          (int) nodeTag(&con->val));
5404                                 break;
5405                 }
5406         }
5407
5408         return buf.data;
5409 }
5410
5411
5412 /*
5413  * SET command
5414  */
5415 void
5416 ExecSetVariableStmt(VariableSetStmt *stmt)
5417 {
5418         GucAction       action = stmt->is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET;
5419
5420         switch (stmt->kind)
5421         {
5422                 case VAR_SET_VALUE:
5423                 case VAR_SET_CURRENT:
5424                         set_config_option(stmt->name,
5425                                                           ExtractSetVariableArgs(stmt),
5426                                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5427                                                           PGC_S_SESSION,
5428                                                           action,
5429                                                           true);
5430                         break;
5431                 case VAR_SET_MULTI:
5432
5433                         /*
5434                          * Special case for special SQL syntax that effectively sets more
5435                          * than one variable per statement.
5436                          */
5437                         if (strcmp(stmt->name, "TRANSACTION") == 0)
5438                         {
5439                                 ListCell   *head;
5440
5441                                 foreach(head, stmt->args)
5442                                 {
5443                                         DefElem    *item = (DefElem *) lfirst(head);
5444
5445                                         if (strcmp(item->defname, "transaction_isolation") == 0)
5446                                                 SetPGVariable("transaction_isolation",
5447                                                                           list_make1(item->arg), stmt->is_local);
5448                                         else if (strcmp(item->defname, "transaction_read_only") == 0)
5449                                                 SetPGVariable("transaction_read_only",
5450                                                                           list_make1(item->arg), stmt->is_local);
5451                                         else
5452                                                 elog(ERROR, "unexpected SET TRANSACTION element: %s",
5453                                                          item->defname);
5454                                 }
5455                         }
5456                         else if (strcmp(stmt->name, "SESSION CHARACTERISTICS") == 0)
5457                         {
5458                                 ListCell   *head;
5459
5460                                 foreach(head, stmt->args)
5461                                 {
5462                                         DefElem    *item = (DefElem *) lfirst(head);
5463
5464                                         if (strcmp(item->defname, "transaction_isolation") == 0)
5465                                                 SetPGVariable("default_transaction_isolation",
5466                                                                           list_make1(item->arg), stmt->is_local);
5467                                         else if (strcmp(item->defname, "transaction_read_only") == 0)
5468                                                 SetPGVariable("default_transaction_read_only",
5469                                                                           list_make1(item->arg), stmt->is_local);
5470                                         else
5471                                                 elog(ERROR, "unexpected SET SESSION element: %s",
5472                                                          item->defname);
5473                                 }
5474                         }
5475                         else
5476                                 elog(ERROR, "unexpected SET MULTI element: %s",
5477                                          stmt->name);
5478                         break;
5479                 case VAR_SET_DEFAULT:
5480                 case VAR_RESET:
5481                         set_config_option(stmt->name,
5482                                                           NULL,
5483                                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5484                                                           PGC_S_SESSION,
5485                                                           action,
5486                                                           true);
5487                         break;
5488                 case VAR_RESET_ALL:
5489                         ResetAllOptions();
5490                         break;
5491         }
5492 }
5493
5494 /*
5495  * Get the value to assign for a VariableSetStmt, or NULL if it's RESET.
5496  * The result is palloc'd.
5497  *
5498  * This is exported for use by actions such as ALTER ROLE SET.
5499  */
5500 char *
5501 ExtractSetVariableArgs(VariableSetStmt *stmt)
5502 {
5503         switch (stmt->kind)
5504         {
5505                 case VAR_SET_VALUE:
5506                         return flatten_set_variable_args(stmt->name, stmt->args);
5507                 case VAR_SET_CURRENT:
5508                         return GetConfigOptionByName(stmt->name, NULL);
5509                 default:
5510                         return NULL;
5511         }
5512 }
5513
5514 /*
5515  * SetPGVariable - SET command exported as an easily-C-callable function.
5516  *
5517  * This provides access to SET TO value, as well as SET TO DEFAULT (expressed
5518  * by passing args == NIL), but not SET FROM CURRENT functionality.
5519  */
5520 void
5521 SetPGVariable(const char *name, List *args, bool is_local)
5522 {
5523         char       *argstring = flatten_set_variable_args(name, args);
5524
5525         /* Note SET DEFAULT (argstring == NULL) is equivalent to RESET */
5526         set_config_option(name,
5527                                           argstring,
5528                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5529                                           PGC_S_SESSION,
5530                                           is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET,
5531                                           true);
5532 }
5533
5534 /*
5535  * SET command wrapped as a SQL callable function.
5536  */
5537 Datum
5538 set_config_by_name(PG_FUNCTION_ARGS)
5539 {
5540         char       *name;
5541         char       *value;
5542         char       *new_value;
5543         bool            is_local;
5544
5545         if (PG_ARGISNULL(0))
5546                 ereport(ERROR,
5547                                 (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
5548                                  errmsg("SET requires parameter name")));
5549
5550         /* Get the GUC variable name */
5551         name = TextDatumGetCString(PG_GETARG_DATUM(0));
5552
5553         /* Get the desired value or set to NULL for a reset request */
5554         if (PG_ARGISNULL(1))
5555                 value = NULL;
5556         else
5557                 value = TextDatumGetCString(PG_GETARG_DATUM(1));
5558
5559         /*
5560          * Get the desired state of is_local. Default to false if provided value
5561          * is NULL
5562          */
5563         if (PG_ARGISNULL(2))
5564                 is_local = false;
5565         else
5566                 is_local = PG_GETARG_BOOL(2);
5567
5568         /* Note SET DEFAULT (argstring == NULL) is equivalent to RESET */
5569         set_config_option(name,
5570                                           value,
5571                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5572                                           PGC_S_SESSION,
5573                                           is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET,
5574                                           true);
5575
5576         /* get the new current value */
5577         new_value = GetConfigOptionByName(name, NULL);
5578
5579         /* Convert return string to text */
5580         PG_RETURN_TEXT_P(cstring_to_text(new_value));
5581 }
5582
5583
5584 /*
5585  * Common code for DefineCustomXXXVariable subroutines: allocate the
5586  * new variable's config struct and fill in generic fields.
5587  */
5588 static struct config_generic *
5589 init_custom_variable(const char *name,
5590                                          const char *short_desc,
5591                                          const char *long_desc,
5592                                          GucContext context,
5593                                          int flags,
5594                                          enum config_type type,
5595                                          size_t sz)
5596 {
5597         struct config_generic *gen;
5598
5599         /*
5600          * Only allow custom PGC_POSTMASTER variables to be created during
5601          * shared library preload; any later than that, we can't ensure that
5602          * the value doesn't change after startup.  This is a fatal elog if it
5603          * happens; just erroring out isn't safe because we don't know what
5604          * the calling loadable module might already have hooked into.
5605          */
5606         if (context == PGC_POSTMASTER &&
5607                 !process_shared_preload_libraries_in_progress)
5608                 elog(FATAL, "cannot create PGC_POSTMASTER variables after startup");
5609
5610         gen = (struct config_generic *) guc_malloc(ERROR, sz);
5611         memset(gen, 0, sz);
5612
5613         gen->name = guc_strdup(ERROR, name);
5614         gen->context = context;
5615         gen->group = CUSTOM_OPTIONS;
5616         gen->short_desc = short_desc;
5617         gen->long_desc = long_desc;
5618         gen->flags = flags;
5619         gen->vartype = type;
5620
5621         return gen;
5622 }
5623
5624 /*
5625  * Common code for DefineCustomXXXVariable subroutines: insert the new
5626  * variable into the GUC variable array, replacing any placeholder.
5627  */
5628 static void
5629 define_custom_variable(struct config_generic * variable)
5630 {
5631         const char *name = variable->name;
5632         const char **nameAddr = &name;
5633         const char *value;
5634         struct config_string *pHolder;
5635         GucContext phcontext;
5636         struct config_generic **res;
5637
5638         /*
5639          * See if there's a placeholder by the same name.
5640          */
5641         res = (struct config_generic **) bsearch((void *) &nameAddr,
5642                                                                                          (void *) guc_variables,
5643                                                                                          num_guc_variables,
5644                                                                                          sizeof(struct config_generic *),
5645                                                                                          guc_var_compare);
5646         if (res == NULL)
5647         {
5648                 /*
5649                  * No placeholder to replace, so we can just add it ... but first,
5650                  * make sure it's initialized to its default value.
5651                  */
5652                 InitializeOneGUCOption(variable);
5653                 add_guc_variable(variable, ERROR);
5654                 return;
5655         }
5656
5657         /*
5658          * This better be a placeholder
5659          */
5660         if (((*res)->flags & GUC_CUSTOM_PLACEHOLDER) == 0)
5661                 ereport(ERROR,
5662                                 (errcode(ERRCODE_INTERNAL_ERROR),
5663                                  errmsg("attempt to redefine parameter \"%s\"", name)));
5664
5665         Assert((*res)->vartype == PGC_STRING);
5666         pHolder = (struct config_string *) (*res);
5667
5668         /*
5669          * First, set the variable to its default value.  We must do this even
5670          * though we intend to immediately apply a new value, since it's possible
5671          * that the new value is invalid.
5672          */
5673         InitializeOneGUCOption(variable);
5674
5675         /*
5676          * Replace the placeholder. We aren't changing the name, so no re-sorting
5677          * is necessary
5678          */
5679         *res = variable;
5680
5681         /*
5682          * Infer context for assignment based on source of existing value.
5683          * We can't tell this with exact accuracy, but we can at least do
5684          * something reasonable in typical cases.
5685          */
5686         switch (pHolder->gen.source)
5687         {
5688                 case PGC_S_DEFAULT:
5689                 case PGC_S_ENV_VAR:
5690                 case PGC_S_FILE:
5691                 case PGC_S_ARGV:
5692                         /*
5693                          * If we got past the check in init_custom_variable, we can
5694                          * safely assume that any existing value for a PGC_POSTMASTER
5695                          * variable was set in postmaster context.
5696                          */
5697                         if (variable->context == PGC_POSTMASTER)
5698                                 phcontext = PGC_POSTMASTER;
5699                         else
5700                                 phcontext = PGC_SIGHUP;
5701                         break;
5702                 case PGC_S_DATABASE:
5703                 case PGC_S_USER:
5704                 case PGC_S_CLIENT:
5705                 case PGC_S_SESSION:
5706                 default:
5707                         phcontext = PGC_USERSET;
5708                         break;
5709         }
5710
5711         /*
5712          * Assign the string value stored in the placeholder to the real variable.
5713          *
5714          * XXX this is not really good enough --- it should be a nontransactional
5715          * assignment, since we don't want it to roll back if the current xact
5716          * fails later.  (Or do we?)
5717          */
5718         value = *pHolder->variable;
5719
5720         if (value)
5721         {
5722                 if (set_config_option(name, value,
5723                                                           phcontext, pHolder->gen.source,
5724                                                           GUC_ACTION_SET, true))
5725                 {
5726                         /* Also copy over any saved source-location information */
5727                         if (pHolder->gen.sourcefile)
5728                                 set_config_sourcefile(name, pHolder->gen.sourcefile,
5729                                                                           pHolder->gen.sourceline);
5730                 }
5731         }
5732
5733         /*
5734          * Free up as much as we conveniently can of the placeholder structure
5735          * (this neglects any stack items...)
5736          */
5737         set_string_field(pHolder, pHolder->variable, NULL);
5738         set_string_field(pHolder, &pHolder->reset_val, NULL);
5739
5740         free(pHolder);
5741 }
5742
5743 void
5744 DefineCustomBoolVariable(const char *name,
5745                                                  const char *short_desc,
5746                                                  const char *long_desc,
5747                                                  bool *valueAddr,
5748                                                  bool bootValue,
5749                                                  GucContext context,
5750                                                  int flags,
5751                                                  GucBoolAssignHook assign_hook,
5752                                                  GucShowHook show_hook)
5753 {
5754         struct config_bool *var;
5755
5756         var = (struct config_bool *)
5757                 init_custom_variable(name, short_desc, long_desc, context, flags,
5758                                                          PGC_BOOL, sizeof(struct config_bool));
5759         var->variable = valueAddr;
5760         var->boot_val = bootValue;
5761         var->reset_val = bootValue;
5762         var->assign_hook = assign_hook;
5763         var->show_hook = show_hook;
5764         define_custom_variable(&var->gen);
5765 }
5766
5767 void
5768 DefineCustomIntVariable(const char *name,
5769                                                 const char *short_desc,
5770                                                 const char *long_desc,
5771                                                 int *valueAddr,
5772                                                 int bootValue,
5773                                                 int minValue,
5774                                                 int maxValue,
5775                                                 GucContext context,
5776                                                 int flags,
5777                                                 GucIntAssignHook assign_hook,
5778                                                 GucShowHook show_hook)
5779 {
5780         struct config_int *var;
5781
5782         var = (struct config_int *)
5783                 init_custom_variable(name, short_desc, long_desc, context, flags,
5784                                                          PGC_INT, sizeof(struct config_int));
5785         var->variable = valueAddr;
5786         var->boot_val = bootValue;
5787         var->reset_val = bootValue;
5788         var->min = minValue;
5789         var->max = maxValue;
5790         var->assign_hook = assign_hook;
5791         var->show_hook = show_hook;
5792         define_custom_variable(&var->gen);
5793 }
5794
5795 void
5796 DefineCustomRealVariable(const char *name,
5797                                                  const char *short_desc,
5798                                                  const char *long_desc,
5799                                                  double *valueAddr,
5800                                                  double bootValue,
5801                                                  double minValue,
5802                                                  double maxValue,
5803                                                  GucContext context,
5804                                                  int flags,
5805                                                  GucRealAssignHook assign_hook,
5806                                                  GucShowHook show_hook)
5807 {
5808         struct config_real *var;
5809
5810         var = (struct config_real *)
5811                 init_custom_variable(name, short_desc, long_desc, context, flags,
5812                                                          PGC_REAL, sizeof(struct config_real));
5813         var->variable = valueAddr;
5814         var->boot_val = bootValue;
5815         var->reset_val = bootValue;
5816         var->min = minValue;
5817         var->max = maxValue;
5818         var->assign_hook = assign_hook;
5819         var->show_hook = show_hook;
5820         define_custom_variable(&var->gen);
5821 }
5822
5823 void
5824 DefineCustomStringVariable(const char *name,
5825                                                    const char *short_desc,
5826                                                    const char *long_desc,
5827                                                    char **valueAddr,
5828                                                    const char *bootValue,
5829                                                    GucContext context,
5830                                                    int flags,
5831                                                    GucStringAssignHook assign_hook,
5832                                                    GucShowHook show_hook)
5833 {
5834         struct config_string *var;
5835
5836         var = (struct config_string *)
5837                 init_custom_variable(name, short_desc, long_desc, context, flags,
5838                                                          PGC_STRING, sizeof(struct config_string));
5839         var->variable = valueAddr;
5840         var->boot_val = bootValue;
5841         /* we could probably do without strdup, but keep it like normal case */
5842         if (var->boot_val)
5843                 var->reset_val = guc_strdup(ERROR, var->boot_val);
5844         var->assign_hook = assign_hook;
5845         var->show_hook = show_hook;
5846         define_custom_variable(&var->gen);
5847 }
5848
5849 void
5850 DefineCustomEnumVariable(const char *name,
5851                                                  const char *short_desc,
5852                                                  const char *long_desc,
5853                                                  int *valueAddr,
5854                                                  int bootValue,
5855                                                  const struct config_enum_entry *options,
5856                                                  GucContext context,
5857                                                  int flags,
5858                                                  GucEnumAssignHook assign_hook,
5859                                                  GucShowHook show_hook)
5860 {
5861         struct config_enum *var;
5862
5863         var = (struct config_enum *)
5864                 init_custom_variable(name, short_desc, long_desc, context, flags,
5865                                                          PGC_ENUM, sizeof(struct config_enum));
5866         var->variable = valueAddr;
5867         var->boot_val = bootValue;
5868         var->reset_val = bootValue;
5869         var->options = options;
5870         var->assign_hook = assign_hook;
5871         var->show_hook = show_hook;
5872         define_custom_variable(&var->gen);
5873 }
5874
5875 void
5876 EmitWarningsOnPlaceholders(const char *className)
5877 {
5878         int                     classLen = strlen(className);
5879         int                     i;
5880
5881         for (i = 0; i < num_guc_variables; i++)
5882         {
5883                 struct config_generic *var = guc_variables[i];
5884
5885                 if ((var->flags & GUC_CUSTOM_PLACEHOLDER) != 0 &&
5886                         strncmp(className, var->name, classLen) == 0 &&
5887                         var->name[classLen] == GUC_QUALIFIER_SEPARATOR)
5888                 {
5889                         ereport(WARNING,
5890                                         (errcode(ERRCODE_UNDEFINED_OBJECT),
5891                                          errmsg("unrecognized configuration parameter \"%s\"",
5892                                                         var->name)));
5893                 }
5894         }
5895 }
5896
5897
5898 /*
5899  * SHOW command
5900  */
5901 void
5902 GetPGVariable(const char *name, DestReceiver *dest)
5903 {
5904         if (guc_name_compare(name, "all") == 0)
5905                 ShowAllGUCConfig(dest);
5906         else
5907                 ShowGUCConfigOption(name, dest);
5908 }
5909
5910 TupleDesc
5911 GetPGVariableResultDesc(const char *name)
5912 {
5913         TupleDesc       tupdesc;
5914
5915         if (guc_name_compare(name, "all") == 0)
5916         {
5917                 /* need a tuple descriptor representing three TEXT columns */
5918                 tupdesc = CreateTemplateTupleDesc(3, false);
5919                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
5920                                                    TEXTOID, -1, 0);
5921                 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
5922                                                    TEXTOID, -1, 0);
5923                 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "description",
5924                                                    TEXTOID, -1, 0);
5925         }
5926         else
5927         {
5928                 const char *varname;
5929
5930                 /* Get the canonical spelling of name */
5931                 (void) GetConfigOptionByName(name, &varname);
5932
5933                 /* need a tuple descriptor representing a single TEXT column */
5934                 tupdesc = CreateTemplateTupleDesc(1, false);
5935                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, varname,
5936                                                    TEXTOID, -1, 0);
5937         }
5938         return tupdesc;
5939 }
5940
5941
5942 /*
5943  * SHOW command
5944  */
5945 static void
5946 ShowGUCConfigOption(const char *name, DestReceiver *dest)
5947 {
5948         TupOutputState *tstate;
5949         TupleDesc       tupdesc;
5950         const char *varname;
5951         char       *value;
5952
5953         /* Get the value and canonical spelling of name */
5954         value = GetConfigOptionByName(name, &varname);
5955
5956         /* need a tuple descriptor representing a single TEXT column */
5957         tupdesc = CreateTemplateTupleDesc(1, false);
5958         TupleDescInitEntry(tupdesc, (AttrNumber) 1, varname,
5959                                            TEXTOID, -1, 0);
5960
5961         /* prepare for projection of tuples */
5962         tstate = begin_tup_output_tupdesc(dest, tupdesc);
5963
5964         /* Send it */
5965         do_text_output_oneline(tstate, value);
5966
5967         end_tup_output(tstate);
5968 }
5969
5970 /*
5971  * SHOW ALL command
5972  */
5973 static void
5974 ShowAllGUCConfig(DestReceiver *dest)
5975 {
5976         bool            am_superuser = superuser();
5977         int                     i;
5978         TupOutputState *tstate;
5979         TupleDesc       tupdesc;
5980         char       *values[3];
5981
5982         /* need a tuple descriptor representing three TEXT columns */
5983         tupdesc = CreateTemplateTupleDesc(3, false);
5984         TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
5985                                            TEXTOID, -1, 0);
5986         TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
5987                                            TEXTOID, -1, 0);
5988         TupleDescInitEntry(tupdesc, (AttrNumber) 3, "description",
5989                                            TEXTOID, -1, 0);
5990
5991
5992         /* prepare for projection of tuples */
5993         tstate = begin_tup_output_tupdesc(dest, tupdesc);
5994
5995         for (i = 0; i < num_guc_variables; i++)
5996         {
5997                 struct config_generic *conf = guc_variables[i];
5998
5999                 if ((conf->flags & GUC_NO_SHOW_ALL) ||
6000                         ((conf->flags & GUC_SUPERUSER_ONLY) && !am_superuser))
6001                         continue;
6002
6003                 /* assign to the values array */
6004                 values[0] = (char *) conf->name;
6005                 values[1] = _ShowOption(conf, true);
6006                 values[2] = (char *) conf->short_desc;
6007
6008                 /* send it to dest */
6009                 do_tup_output(tstate, values);
6010
6011                 /* clean up */
6012                 if (values[1] != NULL)
6013                         pfree(values[1]);
6014         }
6015
6016         end_tup_output(tstate);
6017 }
6018
6019 /*
6020  * Return GUC variable value by name; optionally return canonical
6021  * form of name.  Return value is palloc'd.
6022  */
6023 char *
6024 GetConfigOptionByName(const char *name, const char **varname)
6025 {
6026         struct config_generic *record;
6027
6028         record = find_option(name, false, ERROR);
6029         if (record == NULL)
6030                 ereport(ERROR,
6031                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
6032                            errmsg("unrecognized configuration parameter \"%s\"", name)));
6033         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
6034                 ereport(ERROR,
6035                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
6036                                  errmsg("must be superuser to examine \"%s\"", name)));
6037
6038         if (varname)
6039                 *varname = record->name;
6040
6041         return _ShowOption(record, true);
6042 }
6043
6044 /*
6045  * Return GUC variable value by variable number; optionally return canonical
6046  * form of name.  Return value is palloc'd.
6047  */
6048 void
6049 GetConfigOptionByNum(int varnum, const char **values, bool *noshow)
6050 {
6051         char            buffer[256];
6052         struct config_generic *conf;
6053
6054         /* check requested variable number valid */
6055         Assert((varnum >= 0) && (varnum < num_guc_variables));
6056
6057         conf = guc_variables[varnum];
6058
6059         if (noshow)
6060         {
6061                 if ((conf->flags & GUC_NO_SHOW_ALL) ||
6062                         ((conf->flags & GUC_SUPERUSER_ONLY) && !superuser()))
6063                         *noshow = true;
6064                 else
6065                         *noshow = false;
6066         }
6067
6068         /* first get the generic attributes */
6069
6070         /* name */
6071         values[0] = conf->name;
6072
6073         /* setting : use _ShowOption in order to avoid duplicating the logic */
6074         values[1] = _ShowOption(conf, false);
6075
6076         /* unit */
6077         if (conf->vartype == PGC_INT)
6078         {
6079                 static char buf[8];
6080
6081                 switch (conf->flags & (GUC_UNIT_MEMORY | GUC_UNIT_TIME))
6082                 {
6083                         case GUC_UNIT_KB:
6084                                 values[2] = "kB";
6085                                 break;
6086                         case GUC_UNIT_BLOCKS:
6087                                 snprintf(buf, sizeof(buf), "%dkB", BLCKSZ / 1024);
6088                                 values[2] = buf;
6089                                 break;
6090                         case GUC_UNIT_XBLOCKS:
6091                                 snprintf(buf, sizeof(buf), "%dkB", XLOG_BLCKSZ / 1024);
6092                                 values[2] = buf;
6093                                 break;
6094                         case GUC_UNIT_MS:
6095                                 values[2] = "ms";
6096                                 break;
6097                         case GUC_UNIT_S:
6098                                 values[2] = "s";
6099                                 break;
6100                         case GUC_UNIT_MIN:
6101                                 values[2] = "min";
6102                                 break;
6103                         default:
6104                                 values[2] = "";
6105                                 break;
6106                 }
6107         }
6108         else
6109                 values[2] = NULL;
6110
6111         /* group */
6112         values[3] = config_group_names[conf->group];
6113
6114         /* short_desc */
6115         values[4] = conf->short_desc;
6116
6117         /* extra_desc */
6118         values[5] = conf->long_desc;
6119
6120         /* context */
6121         values[6] = GucContext_Names[conf->context];
6122
6123         /* vartype */
6124         values[7] = config_type_names[conf->vartype];
6125
6126         /* source */
6127         values[8] = GucSource_Names[conf->source];
6128
6129         /* now get the type specifc attributes */
6130         switch (conf->vartype)
6131         {
6132                 case PGC_BOOL:
6133                         {
6134                                 struct config_bool *lconf = (struct config_bool *) conf;
6135
6136                                 /* min_val */
6137                                 values[9] = NULL;
6138
6139                                 /* max_val */
6140                                 values[10] = NULL;
6141
6142                                 /* enumvals */
6143                                 values[11] = NULL;
6144
6145                                 /* boot_val */
6146                                 values[12] = pstrdup(lconf->boot_val ? "on" : "off");
6147
6148                                 /* reset_val */
6149                                 values[13] = pstrdup(lconf->reset_val ? "on" : "off");
6150                         }
6151                         break;
6152
6153                 case PGC_INT:
6154                         {
6155                                 struct config_int *lconf = (struct config_int *) conf;
6156
6157                                 /* min_val */
6158                                 snprintf(buffer, sizeof(buffer), "%d", lconf->min);
6159                                 values[9] = pstrdup(buffer);
6160
6161                                 /* max_val */
6162                                 snprintf(buffer, sizeof(buffer), "%d", lconf->max);
6163                                 values[10] = pstrdup(buffer);
6164
6165                                 /* enumvals */
6166                                 values[11] = NULL;
6167
6168                                 /* boot_val */
6169                                 snprintf(buffer, sizeof(buffer), "%d", lconf->boot_val);
6170                                 values[12] = pstrdup(buffer);
6171
6172                                 /* reset_val */
6173                                 snprintf(buffer, sizeof(buffer), "%d", lconf->reset_val);
6174                                 values[13] = pstrdup(buffer);
6175                         }
6176                         break;
6177
6178                 case PGC_REAL:
6179                         {
6180                                 struct config_real *lconf = (struct config_real *) conf;
6181
6182                                 /* min_val */
6183                                 snprintf(buffer, sizeof(buffer), "%g", lconf->min);
6184                                 values[9] = pstrdup(buffer);
6185
6186                                 /* max_val */
6187                                 snprintf(buffer, sizeof(buffer), "%g", lconf->max);
6188                                 values[10] = pstrdup(buffer);
6189
6190                                 /* enumvals */
6191                                 values[11] = NULL;
6192
6193                                 /* boot_val */
6194                                 snprintf(buffer, sizeof(buffer), "%g", lconf->boot_val);
6195                                 values[12] = pstrdup(buffer);
6196
6197                                 /* reset_val */
6198                                 snprintf(buffer, sizeof(buffer), "%g", lconf->reset_val);
6199                                 values[13] = pstrdup(buffer);
6200                         }
6201                         break;
6202
6203                 case PGC_STRING:
6204                         {
6205                                 struct config_string *lconf = (struct config_string *) conf;
6206
6207                                 /* min_val */
6208                                 values[9] = NULL;
6209
6210                                 /* max_val */
6211                                 values[10] = NULL;
6212
6213                                 /* enumvals */
6214                                 values[11] = NULL;
6215
6216                                 /* boot_val */
6217                                 if (lconf->boot_val == NULL)
6218                                         values[12] = NULL;
6219                                 else
6220                                         values[12] = pstrdup(lconf->boot_val);
6221
6222                                 /* reset_val */
6223                                 if (lconf->reset_val == NULL)
6224                                         values[13] = NULL;
6225                                 else
6226                                         values[13] = pstrdup(lconf->reset_val);
6227                         }
6228                         break;
6229
6230                 case PGC_ENUM:
6231                         {
6232                                 struct config_enum *lconf = (struct config_enum *) conf;
6233
6234                                 /* min_val */
6235                                 values[9] = NULL;
6236
6237                                 /* max_val */
6238                                 values[10] = NULL;
6239
6240                                 /* enumvals */
6241                                 /* NOTE! enumvals with double quotes in them are not supported! */
6242                                 values[11] = config_enum_get_options((struct config_enum *) conf,
6243                                                                                                          "{\"", "\"}", "\",\"");
6244
6245                                 /* boot_val */
6246                                 values[12] = pstrdup(config_enum_lookup_by_value(lconf,
6247                                                                                                                                  lconf->boot_val));
6248
6249                                 /* reset_val */
6250                                 values[13] = pstrdup(config_enum_lookup_by_value(lconf,
6251                                                                                                                                  lconf->reset_val));
6252                         }
6253                         break;
6254
6255                 default:
6256                         {
6257                                 /*
6258                                  * should never get here, but in case we do, set 'em to NULL
6259                                  */
6260
6261                                 /* min_val */
6262                                 values[9] = NULL;
6263
6264                                 /* max_val */
6265                                 values[10] = NULL;
6266
6267                                 /* enumvals */
6268                                 values[11] = NULL;
6269
6270                                 /* boot_val */
6271                                 values[12] = NULL;
6272
6273                                 /* reset_val */
6274                                 values[13] = NULL;
6275                         }
6276                         break;
6277         }
6278
6279         /*
6280          * If the setting came from a config file, set the source location.
6281          * For security reasons, we don't show source file/line number for
6282          * non-superusers.
6283          */
6284         if (conf->source == PGC_S_FILE && superuser())
6285         {
6286                 values[14] = conf->sourcefile;
6287                 snprintf(buffer, sizeof(buffer), "%d", conf->sourceline);
6288                 values[15] = pstrdup(buffer);
6289         }
6290         else
6291         {
6292                 values[14] = NULL;
6293                 values[15] = NULL;
6294         }
6295 }
6296
6297 /*
6298  * Return the total number of GUC variables
6299  */
6300 int
6301 GetNumConfigOptions(void)
6302 {
6303         return num_guc_variables;
6304 }
6305
6306 /*
6307  * show_config_by_name - equiv to SHOW X command but implemented as
6308  * a function.
6309  */
6310 Datum
6311 show_config_by_name(PG_FUNCTION_ARGS)
6312 {
6313         char       *varname;
6314         char       *varval;
6315
6316         /* Get the GUC variable name */
6317         varname = TextDatumGetCString(PG_GETARG_DATUM(0));
6318
6319         /* Get the value */
6320         varval = GetConfigOptionByName(varname, NULL);
6321
6322         /* Convert to text */
6323         PG_RETURN_TEXT_P(cstring_to_text(varval));
6324 }
6325
6326 /*
6327  * show_all_settings - equiv to SHOW ALL command but implemented as
6328  * a Table Function.
6329  */
6330 #define NUM_PG_SETTINGS_ATTS    16
6331
6332 Datum
6333 show_all_settings(PG_FUNCTION_ARGS)
6334 {
6335         FuncCallContext *funcctx;
6336         TupleDesc       tupdesc;
6337         int                     call_cntr;
6338         int                     max_calls;
6339         AttInMetadata *attinmeta;
6340         MemoryContext oldcontext;
6341
6342         /* stuff done only on the first call of the function */
6343         if (SRF_IS_FIRSTCALL())
6344         {
6345                 /* create a function context for cross-call persistence */
6346                 funcctx = SRF_FIRSTCALL_INIT();
6347
6348                 /*
6349                  * switch to memory context appropriate for multiple function calls
6350                  */
6351                 oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
6352
6353                 /*
6354                  * need a tuple descriptor representing NUM_PG_SETTINGS_ATTS columns
6355                  * of the appropriate types
6356                  */
6357                 tupdesc = CreateTemplateTupleDesc(NUM_PG_SETTINGS_ATTS, false);
6358                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
6359                                                    TEXTOID, -1, 0);
6360                 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
6361                                                    TEXTOID, -1, 0);
6362                 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "unit",
6363                                                    TEXTOID, -1, 0);
6364                 TupleDescInitEntry(tupdesc, (AttrNumber) 4, "category",
6365                                                    TEXTOID, -1, 0);
6366                 TupleDescInitEntry(tupdesc, (AttrNumber) 5, "short_desc",
6367                                                    TEXTOID, -1, 0);
6368                 TupleDescInitEntry(tupdesc, (AttrNumber) 6, "extra_desc",
6369                                                    TEXTOID, -1, 0);
6370                 TupleDescInitEntry(tupdesc, (AttrNumber) 7, "context",
6371                                                    TEXTOID, -1, 0);
6372                 TupleDescInitEntry(tupdesc, (AttrNumber) 8, "vartype",
6373                                                    TEXTOID, -1, 0);
6374                 TupleDescInitEntry(tupdesc, (AttrNumber) 9, "source",
6375                                                    TEXTOID, -1, 0);
6376                 TupleDescInitEntry(tupdesc, (AttrNumber) 10, "min_val",
6377                                                    TEXTOID, -1, 0);
6378                 TupleDescInitEntry(tupdesc, (AttrNumber) 11, "max_val",
6379                                                    TEXTOID, -1, 0);
6380                 TupleDescInitEntry(tupdesc, (AttrNumber) 12, "enumvals",
6381                                                    TEXTARRAYOID, -1, 0);
6382                 TupleDescInitEntry(tupdesc, (AttrNumber) 13, "boot_val",
6383                                                    TEXTOID, -1, 0);
6384                 TupleDescInitEntry(tupdesc, (AttrNumber) 14, "reset_val",
6385                                                    TEXTOID, -1, 0);
6386                 TupleDescInitEntry(tupdesc, (AttrNumber) 15, "sourcefile",
6387                                                    TEXTOID, -1, 0);
6388                 TupleDescInitEntry(tupdesc, (AttrNumber) 16, "sourceline",
6389                                                    INT4OID, -1, 0);
6390
6391                 /*
6392                  * Generate attribute metadata needed later to produce tuples from raw
6393                  * C strings
6394                  */
6395                 attinmeta = TupleDescGetAttInMetadata(tupdesc);
6396                 funcctx->attinmeta = attinmeta;
6397
6398                 /* total number of tuples to be returned */
6399                 funcctx->max_calls = GetNumConfigOptions();
6400
6401                 MemoryContextSwitchTo(oldcontext);
6402         }
6403
6404         /* stuff done on every call of the function */
6405         funcctx = SRF_PERCALL_SETUP();
6406
6407         call_cntr = funcctx->call_cntr;
6408         max_calls = funcctx->max_calls;
6409         attinmeta = funcctx->attinmeta;
6410
6411         if (call_cntr < max_calls)      /* do when there is more left to send */
6412         {
6413                 char       *values[NUM_PG_SETTINGS_ATTS];
6414                 bool            noshow;
6415                 HeapTuple       tuple;
6416                 Datum           result;
6417
6418                 /*
6419                  * Get the next visible GUC variable name and value
6420                  */
6421                 do
6422                 {
6423                         GetConfigOptionByNum(call_cntr, (const char **) values, &noshow);
6424                         if (noshow)
6425                         {
6426                                 /* bump the counter and get the next config setting */
6427                                 call_cntr = ++funcctx->call_cntr;
6428
6429                                 /* make sure we haven't gone too far now */
6430                                 if (call_cntr >= max_calls)
6431                                         SRF_RETURN_DONE(funcctx);
6432                         }
6433                 } while (noshow);
6434
6435                 /* build a tuple */
6436                 tuple = BuildTupleFromCStrings(attinmeta, values);
6437
6438                 /* make the tuple into a datum */
6439                 result = HeapTupleGetDatum(tuple);
6440
6441                 SRF_RETURN_NEXT(funcctx, result);
6442         }
6443         else
6444         {
6445                 /* do when there is no more left */
6446                 SRF_RETURN_DONE(funcctx);
6447         }
6448 }
6449
6450 static char *
6451 _ShowOption(struct config_generic * record, bool use_units)
6452 {
6453         char            buffer[256];
6454         const char *val;
6455
6456         switch (record->vartype)
6457         {
6458                 case PGC_BOOL:
6459                         {
6460                                 struct config_bool *conf = (struct config_bool *) record;
6461
6462                                 if (conf->show_hook)
6463                                         val = (*conf->show_hook) ();
6464                                 else
6465                                         val = *conf->variable ? "on" : "off";
6466                         }
6467                         break;
6468
6469                 case PGC_INT:
6470                         {
6471                                 struct config_int *conf = (struct config_int *) record;
6472
6473                                 if (conf->show_hook)
6474                                         val = (*conf->show_hook) ();
6475                                 else
6476                                 {
6477                                         /*
6478                                          * Use int64 arithmetic to avoid overflows in units
6479                                          * conversion.  If INT64_IS_BUSTED we might overflow
6480                                          * anyway and print bogus answers, but there are few
6481                                          * enough such machines that it doesn't seem worth
6482                                          * trying harder.
6483                                          */
6484                                         int64           result = *conf->variable;
6485                                         const char *unit;
6486
6487                                         if (use_units && result > 0 &&
6488                                                 (record->flags & GUC_UNIT_MEMORY))
6489                                         {
6490                                                 switch (record->flags & GUC_UNIT_MEMORY)
6491                                                 {
6492                                                         case GUC_UNIT_BLOCKS:
6493                                                                 result *= BLCKSZ / 1024;
6494                                                                 break;
6495                                                         case GUC_UNIT_XBLOCKS:
6496                                                                 result *= XLOG_BLCKSZ / 1024;
6497                                                                 break;
6498                                                 }
6499
6500                                                 if (result % KB_PER_GB == 0)
6501                                                 {
6502                                                         result /= KB_PER_GB;
6503                                                         unit = "GB";
6504                                                 }
6505                                                 else if (result % KB_PER_MB == 0)
6506                                                 {
6507                                                         result /= KB_PER_MB;
6508                                                         unit = "MB";
6509                                                 }
6510                                                 else
6511                                                 {
6512                                                         unit = "kB";
6513                                                 }
6514                                         }
6515                                         else if (use_units && result > 0 &&
6516                                                          (record->flags & GUC_UNIT_TIME))
6517                                         {
6518                                                 switch (record->flags & GUC_UNIT_TIME)
6519                                                 {
6520                                                         case GUC_UNIT_S:
6521                                                                 result *= MS_PER_S;
6522                                                                 break;
6523                                                         case GUC_UNIT_MIN:
6524                                                                 result *= MS_PER_MIN;
6525                                                                 break;
6526                                                 }
6527
6528                                                 if (result % MS_PER_D == 0)
6529                                                 {
6530                                                         result /= MS_PER_D;
6531                                                         unit = "d";
6532                                                 }
6533                                                 else if (result % MS_PER_H == 0)
6534                                                 {
6535                                                         result /= MS_PER_H;
6536                                                         unit = "h";
6537                                                 }
6538                                                 else if (result % MS_PER_MIN == 0)
6539                                                 {
6540                                                         result /= MS_PER_MIN;
6541                                                         unit = "min";
6542                                                 }
6543                                                 else if (result % MS_PER_S == 0)
6544                                                 {
6545                                                         result /= MS_PER_S;
6546                                                         unit = "s";
6547                                                 }
6548                                                 else
6549                                                 {
6550                                                         unit = "ms";
6551                                                 }
6552                                         }
6553                                         else
6554                                                 unit = "";
6555
6556                                         snprintf(buffer, sizeof(buffer), INT64_FORMAT "%s",
6557                                                          result, unit);
6558                                         val = buffer;
6559                                 }
6560                         }
6561                         break;
6562
6563                 case PGC_REAL:
6564                         {
6565                                 struct config_real *conf = (struct config_real *) record;
6566
6567                                 if (conf->show_hook)
6568                                         val = (*conf->show_hook) ();
6569                                 else
6570                                 {
6571                                         snprintf(buffer, sizeof(buffer), "%g",
6572                                                          *conf->variable);
6573                                         val = buffer;
6574                                 }
6575                         }
6576                         break;
6577
6578                 case PGC_STRING:
6579                         {
6580                                 struct config_string *conf = (struct config_string *) record;
6581
6582                                 if (conf->show_hook)
6583                                         val = (*conf->show_hook) ();
6584                                 else if (*conf->variable && **conf->variable)
6585                                         val = *conf->variable;
6586                                 else
6587                                         val = "";
6588                         }
6589                         break;
6590
6591                 case PGC_ENUM:
6592                         {
6593                                 struct config_enum *conf = (struct config_enum *) record;
6594
6595                                 if(conf->show_hook)
6596                                         val = (*conf->show_hook) ();
6597                                 else
6598                                         val = config_enum_lookup_by_value(conf, *conf->variable);
6599                         }
6600                         break;
6601
6602                 default:
6603                         /* just to keep compiler quiet */
6604                         val = "???";
6605                         break;
6606         }
6607
6608         return pstrdup(val);
6609 }
6610
6611
6612 /*
6613  * Attempt (badly) to detect if a proposed new GUC setting is the same
6614  * as the current value.
6615  *
6616  * XXX this does not really work because it doesn't account for the
6617  * effects of canonicalization of string values by assign_hooks.
6618  */
6619 static bool
6620 is_newvalue_equal(struct config_generic * record, const char *newvalue)
6621 {
6622         /* newvalue == NULL isn't supported */
6623         Assert(newvalue != NULL);
6624
6625         switch (record->vartype)
6626         {
6627                 case PGC_BOOL:
6628                         {
6629                                 struct config_bool *conf = (struct config_bool *) record;
6630                                 bool            newval;
6631
6632                                 return parse_bool(newvalue, &newval)
6633                                         && *conf->variable == newval;
6634                         }
6635                 case PGC_INT:
6636                         {
6637                                 struct config_int *conf = (struct config_int *) record;
6638                                 int                     newval;
6639
6640                                 return parse_int(newvalue, &newval, record->flags, NULL)
6641                                         && *conf->variable == newval;
6642                         }
6643                 case PGC_REAL:
6644                         {
6645                                 struct config_real *conf = (struct config_real *) record;
6646                                 double          newval;
6647
6648                                 return parse_real(newvalue, &newval)
6649                                         && *conf->variable == newval;
6650                         }
6651                 case PGC_STRING:
6652                         {
6653                                 struct config_string *conf = (struct config_string *) record;
6654
6655                                 return *conf->variable != NULL &&
6656                                         strcmp(*conf->variable, newvalue) == 0;
6657                         }
6658
6659                 case PGC_ENUM:
6660                         {
6661                                 struct config_enum *conf = (struct config_enum *) record;
6662                                 int                     newval;
6663
6664                                 return config_enum_lookup_by_name(conf, newvalue, &newval) &&
6665                                         *conf->variable == newval;
6666                         }
6667         }
6668
6669         return false;
6670 }
6671
6672
6673 #ifdef EXEC_BACKEND
6674
6675 /*
6676  *      These routines dump out all non-default GUC options into a binary
6677  *      file that is read by all exec'ed backends.  The format is:
6678  *
6679  *              variable name, string, null terminated
6680  *              variable value, string, null terminated
6681  *              variable source, integer
6682  */
6683 static void
6684 write_one_nondefault_variable(FILE *fp, struct config_generic *gconf)
6685 {
6686         if (gconf->source == PGC_S_DEFAULT)
6687                 return;
6688
6689         fprintf(fp, "%s", gconf->name);
6690         fputc(0, fp);
6691
6692         switch (gconf->vartype)
6693         {
6694                 case PGC_BOOL:
6695                 {
6696                         struct config_bool *conf = (struct config_bool *) gconf;
6697
6698                         if (*conf->variable)
6699                                 fprintf(fp, "true");
6700                         else
6701                                 fprintf(fp, "false");
6702                 }
6703                 break;
6704
6705                 case PGC_INT:
6706                 {
6707                         struct config_int *conf = (struct config_int *) gconf;
6708
6709                         fprintf(fp, "%d", *conf->variable);
6710                 }
6711                 break;
6712
6713                 case PGC_REAL:
6714                 {
6715                         struct config_real *conf = (struct config_real *) gconf;
6716
6717                         /* Could lose precision here? */
6718                         fprintf(fp, "%f", *conf->variable);
6719                 }
6720                 break;
6721
6722                 case PGC_STRING:
6723                 {
6724                         struct config_string *conf = (struct config_string *) gconf;
6725
6726                         fprintf(fp, "%s", *conf->variable);
6727                 }
6728                 break;
6729
6730                 case PGC_ENUM:
6731                 {
6732                         struct config_enum *conf = (struct config_enum *) gconf;
6733
6734                         fprintf(fp, "%s",
6735                                         config_enum_lookup_by_value(conf, *conf->variable));
6736                 }
6737                 break;
6738         }
6739
6740         fputc(0, fp);
6741
6742         fwrite(&gconf->source, sizeof(gconf->source), 1, fp);
6743 }
6744
6745 void
6746 write_nondefault_variables(GucContext context)
6747 {
6748         int                     elevel;
6749         FILE       *fp;
6750         struct config_generic *cvc_conf;
6751         int                     i;
6752
6753         Assert(context == PGC_POSTMASTER || context == PGC_SIGHUP);
6754
6755         elevel = (context == PGC_SIGHUP) ? LOG : ERROR;
6756
6757         /*
6758          * Open file
6759          */
6760         fp = AllocateFile(CONFIG_EXEC_PARAMS_NEW, "w");
6761         if (!fp)
6762         {
6763                 ereport(elevel,
6764                                 (errcode_for_file_access(),
6765                                  errmsg("could not write to file \"%s\": %m",
6766                                                 CONFIG_EXEC_PARAMS_NEW)));
6767                 return;
6768         }
6769
6770         /*
6771          * custom_variable_classes must be written out first; otherwise we might
6772          * reject custom variable values while reading the file.
6773          */
6774         cvc_conf = find_option("custom_variable_classes", false, ERROR);
6775         if (cvc_conf)
6776                 write_one_nondefault_variable(fp, cvc_conf);
6777
6778         for (i = 0; i < num_guc_variables; i++)
6779         {
6780                 struct config_generic *gconf = guc_variables[i];
6781
6782                 if (gconf != cvc_conf)
6783                         write_one_nondefault_variable(fp, gconf);
6784         }
6785
6786         if (FreeFile(fp))
6787         {
6788                 ereport(elevel,
6789                                 (errcode_for_file_access(),
6790                                  errmsg("could not write to file \"%s\": %m",
6791                                                 CONFIG_EXEC_PARAMS_NEW)));
6792                 return;
6793         }
6794
6795         /*
6796          * Put new file in place.  This could delay on Win32, but we don't hold
6797          * any exclusive locks.
6798          */
6799         rename(CONFIG_EXEC_PARAMS_NEW, CONFIG_EXEC_PARAMS);
6800 }
6801
6802
6803 /*
6804  *      Read string, including null byte from file
6805  *
6806  *      Return NULL on EOF and nothing read
6807  */
6808 static char *
6809 read_string_with_null(FILE *fp)
6810 {
6811         int                     i = 0,
6812                                 ch,
6813                                 maxlen = 256;
6814         char       *str = NULL;
6815
6816         do
6817         {
6818                 if ((ch = fgetc(fp)) == EOF)
6819                 {
6820                         if (i == 0)
6821                                 return NULL;
6822                         else
6823                                 elog(FATAL, "invalid format of exec config params file");
6824                 }
6825                 if (i == 0)
6826                         str = guc_malloc(FATAL, maxlen);
6827                 else if (i == maxlen)
6828                         str = guc_realloc(FATAL, str, maxlen *= 2);
6829                 str[i++] = ch;
6830         } while (ch != 0);
6831
6832         return str;
6833 }
6834
6835
6836 /*
6837  *      This routine loads a previous postmaster dump of its non-default
6838  *      settings.
6839  */
6840 void
6841 read_nondefault_variables(void)
6842 {
6843         FILE       *fp;
6844         char       *varname,
6845                            *varvalue;
6846         int                     varsource;
6847
6848         /*
6849          * Open file
6850          */
6851         fp = AllocateFile(CONFIG_EXEC_PARAMS, "r");
6852         if (!fp)
6853         {
6854                 /* File not found is fine */
6855                 if (errno != ENOENT)
6856                         ereport(FATAL,
6857                                         (errcode_for_file_access(),
6858                                          errmsg("could not read from file \"%s\": %m",
6859                                                         CONFIG_EXEC_PARAMS)));
6860                 return;
6861         }
6862
6863         for (;;)
6864         {
6865                 struct config_generic *record;
6866
6867                 if ((varname = read_string_with_null(fp)) == NULL)
6868                         break;
6869
6870                 if ((record = find_option(varname, true, FATAL)) == NULL)
6871                         elog(FATAL, "failed to locate variable %s in exec config params file", varname);
6872                 if ((varvalue = read_string_with_null(fp)) == NULL)
6873                         elog(FATAL, "invalid format of exec config params file");
6874                 if (fread(&varsource, sizeof(varsource), 1, fp) == 0)
6875                         elog(FATAL, "invalid format of exec config params file");
6876
6877                 (void) set_config_option(varname, varvalue, record->context,
6878                                                                  varsource, GUC_ACTION_SET, true);
6879                 free(varname);
6880                 free(varvalue);
6881         }
6882
6883         FreeFile(fp);
6884 }
6885 #endif   /* EXEC_BACKEND */
6886
6887
6888 /*
6889  * A little "long argument" simulation, although not quite GNU
6890  * compliant. Takes a string of the form "some-option=some value" and
6891  * returns name = "some_option" and value = "some value" in malloc'ed
6892  * storage. Note that '-' is converted to '_' in the option name. If
6893  * there is no '=' in the input string then value will be NULL.
6894  */
6895 void
6896 ParseLongOption(const char *string, char **name, char **value)
6897 {
6898         size_t          equal_pos;
6899         char       *cp;
6900
6901         AssertArg(string);
6902         AssertArg(name);
6903         AssertArg(value);
6904
6905         equal_pos = strcspn(string, "=");
6906
6907         if (string[equal_pos] == '=')
6908         {
6909                 *name = guc_malloc(FATAL, equal_pos + 1);
6910                 strlcpy(*name, string, equal_pos + 1);
6911
6912                 *value = guc_strdup(FATAL, &string[equal_pos + 1]);
6913         }
6914         else
6915         {
6916                 /* no equal sign in string */
6917                 *name = guc_strdup(FATAL, string);
6918                 *value = NULL;
6919         }
6920
6921         for (cp = *name; *cp; cp++)
6922                 if (*cp == '-')
6923                         *cp = '_';
6924 }
6925
6926
6927 /*
6928  * Handle options fetched from pg_database.datconfig, pg_authid.rolconfig,
6929  * pg_proc.proconfig, etc.      Caller must specify proper context/source/action.
6930  *
6931  * The array parameter must be an array of TEXT (it must not be NULL).
6932  */
6933 void
6934 ProcessGUCArray(ArrayType *array,
6935                                 GucContext context, GucSource source, GucAction action)
6936 {
6937         int                     i;
6938
6939         Assert(array != NULL);
6940         Assert(ARR_ELEMTYPE(array) == TEXTOID);
6941         Assert(ARR_NDIM(array) == 1);
6942         Assert(ARR_LBOUND(array)[0] == 1);
6943
6944         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
6945         {
6946                 Datum           d;
6947                 bool            isnull;
6948                 char       *s;
6949                 char       *name;
6950                 char       *value;
6951
6952                 d = array_ref(array, 1, &i,
6953                                           -1 /* varlenarray */ ,
6954                                           -1 /* TEXT's typlen */ ,
6955                                           false /* TEXT's typbyval */ ,
6956                                           'i' /* TEXT's typalign */ ,
6957                                           &isnull);
6958
6959                 if (isnull)
6960                         continue;
6961
6962                 s = TextDatumGetCString(d);
6963
6964                 ParseLongOption(s, &name, &value);
6965                 if (!value)
6966                 {
6967                         ereport(WARNING,
6968                                         (errcode(ERRCODE_SYNTAX_ERROR),
6969                                          errmsg("could not parse setting for parameter \"%s\"",
6970                                                         name)));
6971                         free(name);
6972                         continue;
6973                 }
6974
6975                 (void) set_config_option(name, value, context, source, action, true);
6976
6977                 free(name);
6978                 if (value)
6979                         free(value);
6980         }
6981 }
6982
6983
6984 /*
6985  * Add an entry to an option array.  The array parameter may be NULL
6986  * to indicate the current table entry is NULL.
6987  */
6988 ArrayType *
6989 GUCArrayAdd(ArrayType *array, const char *name, const char *value)
6990 {
6991         const char *varname;
6992         Datum           datum;
6993         char       *newval;
6994         ArrayType  *a;
6995
6996         Assert(name);
6997         Assert(value);
6998
6999         /* test if the option is valid */
7000         set_config_option(name, value,
7001                                           superuser() ? PGC_SUSET : PGC_USERSET,
7002                                           PGC_S_TEST, GUC_ACTION_SET, false);
7003
7004         /* convert name to canonical spelling, so we can use plain strcmp */
7005         (void) GetConfigOptionByName(name, &varname);
7006         name = varname;
7007
7008         newval = palloc(strlen(name) + 1 + strlen(value) + 1);
7009         sprintf(newval, "%s=%s", name, value);
7010         datum = CStringGetTextDatum(newval);
7011
7012         if (array)
7013         {
7014                 int                     index;
7015                 bool            isnull;
7016                 int                     i;
7017
7018                 Assert(ARR_ELEMTYPE(array) == TEXTOID);
7019                 Assert(ARR_NDIM(array) == 1);
7020                 Assert(ARR_LBOUND(array)[0] == 1);
7021
7022                 index = ARR_DIMS(array)[0] + 1; /* add after end */
7023
7024                 for (i = 1; i <= ARR_DIMS(array)[0]; i++)
7025                 {
7026                         Datum           d;
7027                         char       *current;
7028
7029                         d = array_ref(array, 1, &i,
7030                                                   -1 /* varlenarray */ ,
7031                                                   -1 /* TEXT's typlen */ ,
7032                                                   false /* TEXT's typbyval */ ,
7033                                                   'i' /* TEXT's typalign */ ,
7034                                                   &isnull);
7035                         if (isnull)
7036                                 continue;
7037                         current = TextDatumGetCString(d);
7038                         if (strncmp(current, newval, strlen(name) + 1) == 0)
7039                         {
7040                                 index = i;
7041                                 break;
7042                         }
7043                 }
7044
7045                 a = array_set(array, 1, &index,
7046                                           datum,
7047                                           false,
7048                                           -1 /* varlena array */ ,
7049                                           -1 /* TEXT's typlen */ ,
7050                                           false /* TEXT's typbyval */ ,
7051                                           'i' /* TEXT's typalign */ );
7052         }
7053         else
7054                 a = construct_array(&datum, 1,
7055                                                         TEXTOID,
7056                                                         -1, false, 'i');
7057
7058         return a;
7059 }
7060
7061
7062 /*
7063  * Delete an entry from an option array.  The array parameter may be NULL
7064  * to indicate the current table entry is NULL.  Also, if the return value
7065  * is NULL then a null should be stored.
7066  */
7067 ArrayType *
7068 GUCArrayDelete(ArrayType *array, const char *name)
7069 {
7070         const char *varname;
7071         ArrayType  *newarray;
7072         int                     i;
7073         int                     index;
7074
7075         Assert(name);
7076
7077         /* test if the option is valid */
7078         set_config_option(name, NULL,
7079                                           superuser() ? PGC_SUSET : PGC_USERSET,
7080                                           PGC_S_TEST, GUC_ACTION_SET, false);
7081
7082         /* convert name to canonical spelling, so we can use plain strcmp */
7083         (void) GetConfigOptionByName(name, &varname);
7084         name = varname;
7085
7086         /* if array is currently null, then surely nothing to delete */
7087         if (!array)
7088                 return NULL;
7089
7090         newarray = NULL;
7091         index = 1;
7092
7093         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
7094         {
7095                 Datum           d;
7096                 char       *val;
7097                 bool            isnull;
7098
7099                 d = array_ref(array, 1, &i,
7100                                           -1 /* varlenarray */ ,
7101                                           -1 /* TEXT's typlen */ ,
7102                                           false /* TEXT's typbyval */ ,
7103                                           'i' /* TEXT's typalign */ ,
7104                                           &isnull);
7105                 if (isnull)
7106                         continue;
7107                 val = TextDatumGetCString(d);
7108
7109                 /* ignore entry if it's what we want to delete */
7110                 if (strncmp(val, name, strlen(name)) == 0
7111                         && val[strlen(name)] == '=')
7112                         continue;
7113
7114                 /* else add it to the output array */
7115                 if (newarray)
7116                 {
7117                         newarray = array_set(newarray, 1, &index,
7118                                                                  d,
7119                                                                  false,
7120                                                                  -1 /* varlenarray */ ,
7121                                                                  -1 /* TEXT's typlen */ ,
7122                                                                  false /* TEXT's typbyval */ ,
7123                                                                  'i' /* TEXT's typalign */ );
7124                 }
7125                 else
7126                         newarray = construct_array(&d, 1,
7127                                                                            TEXTOID,
7128                                                                            -1, false, 'i');
7129
7130                 index++;
7131         }
7132
7133         return newarray;
7134 }
7135
7136
7137 /*
7138  * assign_hook and show_hook subroutines
7139  */
7140
7141 static const char *
7142 assign_log_destination(const char *value, bool doit, GucSource source)
7143 {
7144         char       *rawstring;
7145         List       *elemlist;
7146         ListCell   *l;
7147         int                     newlogdest = 0;
7148
7149         /* Need a modifiable copy of string */
7150         rawstring = pstrdup(value);
7151
7152         /* Parse string into list of identifiers */
7153         if (!SplitIdentifierString(rawstring, ',', &elemlist))
7154         {
7155                 /* syntax error in list */
7156                 pfree(rawstring);
7157                 list_free(elemlist);
7158                 ereport(GUC_complaint_elevel(source),
7159                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7160                         errmsg("invalid list syntax for parameter \"log_destination\"")));
7161                 return NULL;
7162         }
7163
7164         foreach(l, elemlist)
7165         {
7166                 char       *tok = (char *) lfirst(l);
7167
7168                 if (pg_strcasecmp(tok, "stderr") == 0)
7169                         newlogdest |= LOG_DESTINATION_STDERR;
7170                 else if (pg_strcasecmp(tok, "csvlog") == 0)
7171                         newlogdest |= LOG_DESTINATION_CSVLOG;
7172 #ifdef HAVE_SYSLOG
7173                 else if (pg_strcasecmp(tok, "syslog") == 0)
7174                         newlogdest |= LOG_DESTINATION_SYSLOG;
7175 #endif
7176 #ifdef WIN32
7177                 else if (pg_strcasecmp(tok, "eventlog") == 0)
7178                         newlogdest |= LOG_DESTINATION_EVENTLOG;
7179 #endif
7180                 else
7181                 {
7182                         ereport(GUC_complaint_elevel(source),
7183                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7184                                   errmsg("unrecognized \"log_destination\" key word: \"%s\"",
7185                                                  tok)));
7186                         pfree(rawstring);
7187                         list_free(elemlist);
7188                         return NULL;
7189                 }
7190         }
7191
7192         if (doit)
7193                 Log_destination = newlogdest;
7194
7195         pfree(rawstring);
7196         list_free(elemlist);
7197
7198         return value;
7199 }
7200
7201 #ifdef HAVE_SYSLOG
7202
7203 static bool
7204 assign_syslog_facility(int newval, bool doit, GucSource source)
7205 {
7206         if (doit)
7207                 set_syslog_parameters(syslog_ident_str ? syslog_ident_str : "postgres",
7208                                                           newval);
7209
7210         return true;
7211 }
7212
7213 static const char *
7214 assign_syslog_ident(const char *ident, bool doit, GucSource source)
7215 {
7216         if (doit)
7217                 set_syslog_parameters(ident, syslog_facility);
7218
7219         return ident;
7220 }
7221 #endif   /* HAVE_SYSLOG */
7222
7223
7224 static bool
7225 assign_session_replication_role(int newval, bool doit, GucSource source)
7226 {
7227         /*
7228          * Must flush the plan cache when changing replication role; but don't
7229          * flush unnecessarily.
7230          */
7231         if (doit && SessionReplicationRole != newval)
7232         {
7233                 ResetPlanCache();
7234         }
7235
7236         return true;
7237 }
7238
7239 static const char *
7240 show_num_temp_buffers(void)
7241 {
7242         /*
7243          * We show the GUC var until local buffers have been initialized, and
7244          * NLocBuffer afterwards.
7245          */
7246         static char nbuf[32];
7247
7248         sprintf(nbuf, "%d", NLocBuffer ? NLocBuffer : num_temp_buffers);
7249         return nbuf;
7250 }
7251
7252 static bool
7253 assign_phony_autocommit(bool newval, bool doit, GucSource source)
7254 {
7255         if (!newval)
7256         {
7257                 ereport(GUC_complaint_elevel(source),
7258                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
7259                                  errmsg("SET AUTOCOMMIT TO OFF is no longer supported")));
7260                 return false;
7261         }
7262         return true;
7263 }
7264
7265 static const char *
7266 assign_custom_variable_classes(const char *newval, bool doit, GucSource source)
7267 {
7268         /*
7269          * Check syntax. newval must be a comma separated list of identifiers.
7270          * Whitespace is allowed but removed from the result.
7271          */
7272         bool            hasSpaceAfterToken = false;
7273         const char *cp = newval;
7274         int                     symLen = 0;
7275         char            c;
7276         StringInfoData buf;
7277
7278         initStringInfo(&buf);
7279         while ((c = *cp++) != '\0')
7280         {
7281                 if (isspace((unsigned char) c))
7282                 {
7283                         if (symLen > 0)
7284                                 hasSpaceAfterToken = true;
7285                         continue;
7286                 }
7287
7288                 if (c == ',')
7289                 {
7290                         if (symLen > 0)         /* terminate identifier */
7291                         {
7292                                 appendStringInfoChar(&buf, ',');
7293                                 symLen = 0;
7294                         }
7295                         hasSpaceAfterToken = false;
7296                         continue;
7297                 }
7298
7299                 if (hasSpaceAfterToken || !(isalnum((unsigned char) c) || c == '_'))
7300                 {
7301                         /*
7302                          * Syntax error due to token following space after token or
7303                          * non-identifier character
7304                          */
7305                         pfree(buf.data);
7306                         return NULL;
7307                 }
7308                 appendStringInfoChar(&buf, c);
7309                 symLen++;
7310         }
7311
7312         /* Remove stray ',' at end */
7313         if (symLen == 0 && buf.len > 0)
7314                 buf.data[--buf.len] = '\0';
7315
7316         /* GUC wants the result malloc'd */
7317         newval = guc_strdup(LOG, buf.data);
7318
7319         pfree(buf.data);
7320         return newval;
7321 }
7322
7323 static bool
7324 assign_debug_assertions(bool newval, bool doit, GucSource source)
7325 {
7326 #ifndef USE_ASSERT_CHECKING
7327         if (newval)
7328         {
7329                 ereport(GUC_complaint_elevel(source),
7330                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7331                            errmsg("assertion checking is not supported by this build")));
7332                 return false;
7333         }
7334 #endif
7335         return true;
7336 }
7337
7338 static bool
7339 assign_ssl(bool newval, bool doit, GucSource source)
7340 {
7341 #ifndef USE_SSL
7342         if (newval)
7343         {
7344                 ereport(GUC_complaint_elevel(source),
7345                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7346                                  errmsg("SSL is not supported by this build")));
7347                 return false;
7348         }
7349 #endif
7350         return true;
7351 }
7352
7353 static bool
7354 assign_stage_log_stats(bool newval, bool doit, GucSource source)
7355 {
7356         if (newval && log_statement_stats)
7357         {
7358                 ereport(GUC_complaint_elevel(source),
7359                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7360                                  errmsg("cannot enable parameter when \"log_statement_stats\" is true")));
7361                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7362                 if (source != PGC_S_OVERRIDE)
7363                         return false;
7364         }
7365         return true;
7366 }
7367
7368 static bool
7369 assign_log_stats(bool newval, bool doit, GucSource source)
7370 {
7371         if (newval &&
7372                 (log_parser_stats || log_planner_stats || log_executor_stats))
7373         {
7374                 ereport(GUC_complaint_elevel(source),
7375                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7376                                  errmsg("cannot enable \"log_statement_stats\" when "
7377                                                 "\"log_parser_stats\", \"log_planner_stats\", "
7378                                                 "or \"log_executor_stats\" is true")));
7379                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7380                 if (source != PGC_S_OVERRIDE)
7381                         return false;
7382         }
7383         return true;
7384 }
7385
7386 static bool
7387 assign_transaction_read_only(bool newval, bool doit, GucSource source)
7388 {
7389         /* Can't go to r/w mode inside a r/o transaction */
7390         if (newval == false && XactReadOnly && IsSubTransaction())
7391         {
7392                 ereport(GUC_complaint_elevel(source),
7393                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7394                                  errmsg("cannot set transaction read-write mode inside a read-only transaction")));
7395                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7396                 if (source != PGC_S_OVERRIDE)
7397                         return false;
7398         }
7399         return true;
7400 }
7401
7402 static const char *
7403 assign_canonical_path(const char *newval, bool doit, GucSource source)
7404 {
7405         if (doit)
7406         {
7407                 char       *canon_val = guc_strdup(ERROR, newval);
7408
7409                 canonicalize_path(canon_val);
7410                 return canon_val;
7411         }
7412         else
7413                 return newval;
7414 }
7415
7416 static const char *
7417 assign_timezone_abbreviations(const char *newval, bool doit, GucSource source)
7418 {
7419         /*
7420          * The powerup value shown above for timezone_abbreviations is "UNKNOWN".
7421          * When we see this we just do nothing.  If this value isn't overridden
7422          * from the config file then pg_timezone_abbrev_initialize() will
7423          * eventually replace it with "Default".  This hack has two purposes: to
7424          * avoid wasting cycles loading values that might soon be overridden from
7425          * the config file, and to avoid trying to read the timezone abbrev files
7426          * during InitializeGUCOptions().  The latter doesn't work in an
7427          * EXEC_BACKEND subprocess because my_exec_path hasn't been set yet and so
7428          * we can't locate PGSHAREDIR.  (Essentially the same hack is used to
7429          * delay initializing TimeZone ... if we have any more, we should try to
7430          * clean up and centralize this mechanism ...)
7431          */
7432         if (strcmp(newval, "UNKNOWN") == 0)
7433         {
7434                 return newval;
7435         }
7436
7437         /* Loading abbrev file is expensive, so only do it when value changes */
7438         if (timezone_abbreviations_string == NULL ||
7439                 strcmp(timezone_abbreviations_string, newval) != 0)
7440         {
7441                 int                     elevel;
7442
7443                 /*
7444                  * If reading config file, only the postmaster should bleat loudly
7445                  * about problems.      Otherwise, it's just this one process doing it,
7446                  * and we use WARNING message level.
7447                  */
7448                 if (source == PGC_S_FILE)
7449                         elevel = IsUnderPostmaster ? DEBUG3 : LOG;
7450                 else
7451                         elevel = WARNING;
7452                 if (!load_tzoffsets(newval, doit, elevel))
7453                         return NULL;
7454         }
7455         return newval;
7456 }
7457
7458 /*
7459  * pg_timezone_abbrev_initialize --- set default value if not done already
7460  *
7461  * This is called after initial loading of postgresql.conf.  If no
7462  * timezone_abbreviations setting was found therein, select default.
7463  */
7464 void
7465 pg_timezone_abbrev_initialize(void)
7466 {
7467         if (strcmp(timezone_abbreviations_string, "UNKNOWN") == 0)
7468         {
7469                 SetConfigOption("timezone_abbreviations", "Default",
7470                                                 PGC_POSTMASTER, PGC_S_ARGV);
7471         }
7472 }
7473
7474 static const char *
7475 show_archive_command(void)
7476 {
7477         if (XLogArchiveMode)
7478                 return XLogArchiveCommand;
7479         else
7480                 return "(disabled)";
7481 }
7482
7483 static bool
7484 assign_tcp_keepalives_idle(int newval, bool doit, GucSource source)
7485 {
7486         if (doit)
7487                 return (pq_setkeepalivesidle(newval, MyProcPort) == STATUS_OK);
7488
7489         return true;
7490 }
7491
7492 static const char *
7493 show_tcp_keepalives_idle(void)
7494 {
7495         static char nbuf[16];
7496
7497         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesidle(MyProcPort));
7498         return nbuf;
7499 }
7500
7501 static bool
7502 assign_tcp_keepalives_interval(int newval, bool doit, GucSource source)
7503 {
7504         if (doit)
7505                 return (pq_setkeepalivesinterval(newval, MyProcPort) == STATUS_OK);
7506
7507         return true;
7508 }
7509
7510 static const char *
7511 show_tcp_keepalives_interval(void)
7512 {
7513         static char nbuf[16];
7514
7515         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesinterval(MyProcPort));
7516         return nbuf;
7517 }
7518
7519 static bool
7520 assign_tcp_keepalives_count(int newval, bool doit, GucSource source)
7521 {
7522         if (doit)
7523                 return (pq_setkeepalivescount(newval, MyProcPort) == STATUS_OK);
7524
7525         return true;
7526 }
7527
7528 static const char *
7529 show_tcp_keepalives_count(void)
7530 {
7531         static char nbuf[16];
7532
7533         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivescount(MyProcPort));
7534         return nbuf;
7535 }
7536
7537 static bool
7538 assign_maxconnections(int newval, bool doit, GucSource source)
7539 {
7540         if (newval + autovacuum_max_workers > INT_MAX / 4)
7541                 return false;
7542
7543         if (doit)
7544                 MaxBackends = newval + autovacuum_max_workers;
7545
7546         return true;
7547 }
7548
7549 static bool
7550 assign_autovacuum_max_workers(int newval, bool doit, GucSource source)
7551 {
7552         if (newval + MaxConnections > INT_MAX / 4)
7553                 return false;
7554
7555         if (doit)
7556                 MaxBackends = newval + MaxConnections;
7557
7558         return true;
7559 }
7560
7561 static bool
7562 assign_effective_io_concurrency(int newval, bool doit, GucSource source)
7563 {
7564 #ifdef USE_PREFETCH
7565         double          new_prefetch_pages = 0.0;
7566         int                     i;
7567
7568         /*----------
7569          * The user-visible GUC parameter is the number of drives (spindles),
7570          * which we need to translate to a number-of-pages-to-prefetch target.
7571          *
7572          * The expected number of prefetch pages needed to keep N drives busy is:
7573          *
7574          * drives |   I/O requests
7575          * -------+----------------
7576          *      1 |   1
7577          *      2 |   2/1 + 2/2 = 3
7578          *      3 |   3/1 + 3/2 + 3/3 = 5 1/2
7579          *      4 |   4/1 + 4/2 + 4/3 + 4/4 = 8 1/3
7580          *      n |   n * H(n)
7581          *
7582          * This is called the "coupon collector problem" and H(n) is called the
7583          * harmonic series.  This could be approximated by n * ln(n), but for
7584          * reasonable numbers of drives we might as well just compute the series.
7585          *
7586          * Alternatively we could set the target to the number of pages necessary
7587          * so that the expected number of active spindles is some arbitrary
7588          * percentage of the total.  This sounds the same but is actually slightly
7589          * different.  The result ends up being ln(1-P)/ln((n-1)/n) where P is
7590          * that desired fraction.
7591          *
7592          * Experimental results show that both of these formulas aren't aggressive
7593          * enough, but we don't really have any better proposals.
7594          *
7595          * Note that if newval = 0 (disabled), we must set target = 0.
7596          *----------
7597          */
7598
7599         for (i = 1; i <= newval; i++)
7600                 new_prefetch_pages += (double) newval / (double) i;
7601
7602         /* This range check shouldn't fail, but let's be paranoid */
7603         if (new_prefetch_pages >= 0.0 && new_prefetch_pages < (double) INT_MAX)
7604         {
7605                 if (doit)
7606                         target_prefetch_pages = (int) rint(new_prefetch_pages);
7607                 return true;
7608         }
7609         else
7610                 return false;
7611 #else
7612         return true;
7613 #endif /* USE_PREFETCH */
7614 }
7615
7616 static const char *
7617 assign_pgstat_temp_directory(const char *newval, bool doit, GucSource source)
7618 {
7619         if (doit)
7620         {
7621                 if (pgstat_stat_tmpname)
7622                         free(pgstat_stat_tmpname);
7623                 if (pgstat_stat_filename)
7624                         free(pgstat_stat_filename);
7625
7626                 pgstat_stat_tmpname = guc_malloc(FATAL, strlen(newval) + 12);  /* /pgstat.tmp */
7627                 pgstat_stat_filename = guc_malloc(FATAL, strlen(newval) + 13); /* /pgstat.stat */
7628
7629                 sprintf(pgstat_stat_tmpname, "%s/pgstat.tmp", newval);
7630                 sprintf(pgstat_stat_filename, "%s/pgstat.stat", newval);
7631         }
7632
7633         return newval;
7634 }
7635
7636 #include "guc-file.c"