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) 2000-2008, 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 1.471 2008/09/10 18:09:19 alvherre Exp $
  14  *
  15  *--------------------------------------------------------------------
  16  */
  17 #include "postgres.h"
  18
  19 #include <ctype.h>
  20 #include <float.h>
  21 #include <limits.h>
  22 #include <unistd.h>
  23 #include <sys/stat.h>
  24 #ifdef HAVE_SYSLOG
  25 #include <syslog.h>
  26 #endif
  27
  28 #include "access/gin.h"
  29 #include "access/transam.h"
  30 #include "access/twophase.h"
  31 #include "access/xact.h"
  32 #include "catalog/namespace.h"
  33 #include "commands/async.h"
  34 #include "commands/prepare.h"
  35 #include "commands/vacuum.h"
  36 #include "commands/variable.h"
  37 #include "commands/trigger.h"
  38 #include "funcapi.h"
  39 #include "libpq/auth.h"
  40 #include "libpq/pqformat.h"
  41 #include "miscadmin.h"
  42 #include "optimizer/cost.h"
  43 #include "optimizer/geqo.h"
  44 #include "optimizer/paths.h"
  45 #include "optimizer/planmain.h"
  46 #include "parser/gramparse.h"
  47 #include "parser/parse_expr.h"
  48 #include "parser/parse_relation.h"
  49 #include "parser/parse_type.h"
  50 #include "parser/scansup.h"
  51 #include "pgstat.h"
  52 #include "postmaster/autovacuum.h"
  53 #include "postmaster/bgwriter.h"
  54 #include "postmaster/postmaster.h"
  55 #include "postmaster/syslogger.h"
  56 #include "postmaster/walwriter.h"
  57 #include "regex/regex.h"
  58 #include "storage/bufmgr.h"
  59 #include "storage/fd.h"
  60 #include "storage/freespace.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_autovacuum_max_workers(int newval, bool doit, GucSource source);
 168 static bool assign_maxconnections(int newval, bool doit, GucSource source);
 169 static const char *assign_pgstat_temp_directory(const char *newval, bool doit, GucSource source);
 170
 171 static char *config_enum_get_options(struct config_enum *record,
 172                                                                          const char *prefix, const char *suffix);
 173
 174
 175 /*
 176  * Options for enum values defined in this module.
 177  */
 178
 179 /*
 180  * We have different sets for client and server message level options because
 181  * they sort slightly different (see "log" level)
 182  */
 183 static const struct config_enum_entry client_message_level_options[] = {
 184         {"debug", DEBUG2, true},
 185         {"debug5", DEBUG5, false},
 186         {"debug4", DEBUG4, false},
 187         {"debug3", DEBUG3, false},
 188         {"debug2", DEBUG2, false},
 189         {"debug1", DEBUG1, false},
 190         {"log", LOG, false},
 191         {"info", INFO, true},
 192         {"notice", NOTICE, false},
 193         {"warning", WARNING, false},
 194         {"error", ERROR, false},
 195         {"fatal", FATAL, true},
 196         {"panic", PANIC, true},
 197         {NULL, 0, false}
 198 };
 199
 200 static const struct config_enum_entry server_message_level_options[] = {
 201         {"debug", DEBUG2, true},
 202         {"debug5", DEBUG5, false},
 203         {"debug4", DEBUG4, false},
 204         {"debug3", DEBUG3, false},
 205         {"debug2", DEBUG2, false},
 206         {"debug1", DEBUG1, false},
 207         {"info", INFO, false},
 208         {"notice", NOTICE, false},
 209         {"warning", WARNING, false},
 210         {"error", ERROR, false},
 211         {"log", LOG, false},
 212         {"fatal", FATAL, false},
 213         {"panic", PANIC, false},
 214         {NULL, 0, false}
 215 };
 216
 217 static const struct config_enum_entry log_error_verbosity_options[] = {
 218         {"terse", PGERROR_TERSE, false},
 219         {"default", PGERROR_DEFAULT, false},
 220         {"verbose", PGERROR_VERBOSE, false},
 221         {NULL, 0, false}
 222 };
 223
 224 static const struct config_enum_entry log_statement_options[] = {
 225         {"none", LOGSTMT_NONE, false},
 226         {"ddl", LOGSTMT_DDL, false},
 227         {"mod", LOGSTMT_MOD, false},
 228         {"all", LOGSTMT_ALL, false},
 229         {NULL, 0, false}
 230 };
 231
 232 static const struct config_enum_entry regex_flavor_options[] = {
 233     {"advanced", REG_ADVANCED, false},
 234     {"extended", REG_EXTENDED, false},
 235     {"basic", REG_BASIC, false},
 236     {NULL, 0, false}
 237 };
 238
 239 static const struct config_enum_entry isolation_level_options[] = {
 240         {"serializable", XACT_SERIALIZABLE, false},
 241         {"repeatable read", XACT_REPEATABLE_READ, false},
 242         {"read committed", XACT_READ_COMMITTED, false},
 243         {"read uncommitted", XACT_READ_UNCOMMITTED, false},
 244         {NULL, 0}
 245 };
 246
 247 static const struct config_enum_entry session_replication_role_options[] = {
 248         {"origin", SESSION_REPLICATION_ROLE_ORIGIN, false},
 249         {"replica", SESSION_REPLICATION_ROLE_REPLICA, false},
 250         {"local", SESSION_REPLICATION_ROLE_LOCAL, false},
 251         {NULL, 0, false}
 252 };
 253
 254 #ifdef HAVE_SYSLOG
 255 static const struct config_enum_entry syslog_facility_options[] = {
 256         {"local0", LOG_LOCAL0, false},
 257         {"local1", LOG_LOCAL1, false},
 258         {"local2", LOG_LOCAL2, false},
 259         {"local3", LOG_LOCAL3, false},
 260         {"local4", LOG_LOCAL4, false},
 261         {"local5", LOG_LOCAL5, false},
 262         {"local6", LOG_LOCAL6, false},
 263         {"local7", LOG_LOCAL7, false},
 264         {NULL, 0}
 265 };
 266 #endif
 267
 268 static const struct config_enum_entry track_function_options[] = {
 269         {"none", TRACK_FUNC_OFF, false},
 270         {"pl", TRACK_FUNC_PL, false},
 271         {"all", TRACK_FUNC_ALL, false},
 272         {NULL, 0, false}
 273 };
 274
 275 static const struct config_enum_entry xmlbinary_options[] = {
 276         {"base64", XMLBINARY_BASE64, false},
 277         {"hex", XMLBINARY_HEX, false},
 278         {NULL, 0, false}
 279 };
 280
 281 static const struct config_enum_entry xmloption_options[] = {
 282         {"content", XMLOPTION_CONTENT, false},
 283         {"document", XMLOPTION_DOCUMENT, false},
 284         {NULL, 0, false}
 285 };
 286
 287 /*
 288  * Although only "on", "off", and "safe_encoding" are documented, we
 289  * accept all the likely variants of "on" and "off".
 290  */
 291 static const struct config_enum_entry backslash_quote_options[] = {
 292         {"safe_encoding", BACKSLASH_QUOTE_SAFE_ENCODING, false},
 293         {"on", BACKSLASH_QUOTE_ON, false},
 294         {"off", BACKSLASH_QUOTE_OFF, false},
 295         {"true", BACKSLASH_QUOTE_ON, true},
 296         {"false", BACKSLASH_QUOTE_OFF, true},
 297         {"yes", BACKSLASH_QUOTE_ON, true},
 298         {"no", BACKSLASH_QUOTE_OFF, true},
 299         {"1", BACKSLASH_QUOTE_ON, true},
 300         {"0", BACKSLASH_QUOTE_OFF, true},
 301         {NULL, 0, false}
 302 };
 303
 304 /*
 305  * Options for enum values stored in other modules
 306  */
 307 extern const struct config_enum_entry sync_method_options[];
 308
 309 /*
 310  * GUC option variables that are exported from this module
 311  */
 312 #ifdef USE_ASSERT_CHECKING
 313 bool            assert_enabled = true;
 314 #else
 315 bool            assert_enabled = false;
 316 #endif
 317 bool            log_duration = false;
 318 bool            Debug_print_plan = false;
 319 bool            Debug_print_parse = false;
 320 bool            Debug_print_rewritten = false;
 321 bool            Debug_pretty_print = true;
 322
 323 bool            log_parser_stats = false;
 324 bool            log_planner_stats = false;
 325 bool            log_executor_stats = false;
 326 bool            log_statement_stats = false;            /* this is sort of all three
 327                                                                                                  * above together */
 328 bool            log_btree_build_stats = false;
 329
 330 bool            check_function_bodies = true;
 331 bool            default_with_oids = false;
 332 bool            SQL_inheritance = true;
 333
 334 bool            Password_encryption = true;
 335
 336 int                     log_min_error_statement = ERROR;
 337 int                     log_min_messages = WARNING;
 338 int                     client_min_messages = NOTICE;
 339 int                     log_min_duration_statement = -1;
 340 int                     log_temp_files = -1;
 341
 342 int                     num_temp_buffers = 1000;
 343
 344 char       *ConfigFileName;
 345 char       *HbaFileName;
 346 char       *IdentFileName;
 347 char       *external_pid_file;
 348
 349 char       *pgstat_temp_directory;
 350
 351 int                     tcp_keepalives_idle;
 352 int                     tcp_keepalives_interval;
 353 int                     tcp_keepalives_count;
 354
 355 /*
 356  * These variables are all dummies that don't do anything, except in some
 357  * cases provide the value for SHOW to display.  The real state is elsewhere
 358  * and is kept in sync by assign_hooks.
 359  */
 360 static char *log_destination_string;
 361
 362 #ifdef HAVE_SYSLOG
 363 static char *syslog_ident_str;
 364 #endif
 365 static bool phony_autocommit;
 366 static bool session_auth_is_superuser;
 367 static double phony_random_seed;
 368 static char *client_encoding_string;
 369 static char *datestyle_string;
 370 static char *locale_collate;
 371 static char *locale_ctype;
 372 static char *server_encoding_string;
 373 static char *server_version_string;
 374 static int      server_version_num;
 375 static char *timezone_string;
 376 static char *log_timezone_string;
 377 static char *timezone_abbreviations_string;
 378 static char *XactIsoLevel_string;
 379 static char *data_directory;
 380 static char *custom_variable_classes;
 381 static int      max_function_args;
 382 static int      max_index_keys;
 383 static int      max_identifier_length;
 384 static int      block_size;
 385 static int      segment_size;
 386 static int      wal_block_size;
 387 static int      wal_segment_size;
 388 static bool integer_datetimes;
 389
 390 /* should be static, but commands/variable.c needs to get at these */
 391 char       *role_string;
 392 char       *session_authorization_string;
 393
 394
 395 /*
 396  * Displayable names for context types (enum GucContext)
 397  *
 398  * Note: these strings are deliberately not localized.
 399  */
 400 const char *const GucContext_Names[] =
 401 {
 402          /* PGC_INTERNAL */ "internal",
 403          /* PGC_POSTMASTER */ "postmaster",
 404          /* PGC_SIGHUP */ "sighup",
 405          /* PGC_BACKEND */ "backend",
 406          /* PGC_SUSET */ "superuser",
 407          /* PGC_USERSET */ "user"
 408 };
 409
 410 /*
 411  * Displayable names for source types (enum GucSource)
 412  *
 413  * Note: these strings are deliberately not localized.
 414  */
 415 const char *const GucSource_Names[] =
 416 {
 417          /* PGC_S_DEFAULT */ "default",
 418          /* PGC_S_ENV_VAR */ "environment variable",
 419          /* PGC_S_FILE */ "configuration file",
 420          /* PGC_S_ARGV */ "command line",
 421          /* PGC_S_DATABASE */ "database",
 422          /* PGC_S_USER */ "user",
 423          /* PGC_S_CLIENT */ "client",
 424          /* PGC_S_OVERRIDE */ "override",
 425          /* PGC_S_INTERACTIVE */ "interactive",
 426          /* PGC_S_TEST */ "test",
 427          /* PGC_S_SESSION */ "session"
 428 };
 429
 430 /*
 431  * Displayable names for the groupings defined in enum config_group
 432  */
 433 const char *const config_group_names[] =
 434 {
 435         /* UNGROUPED */
 436         gettext_noop("Ungrouped"),
 437         /* FILE_LOCATIONS */
 438         gettext_noop("File Locations"),
 439         /* CONN_AUTH */
 440         gettext_noop("Connections and Authentication"),
 441         /* CONN_AUTH_SETTINGS */
 442         gettext_noop("Connections and Authentication / Connection Settings"),
 443         /* CONN_AUTH_SECURITY */
 444         gettext_noop("Connections and Authentication / Security and Authentication"),
 445         /* RESOURCES */
 446         gettext_noop("Resource Usage"),
 447         /* RESOURCES_MEM */
 448         gettext_noop("Resource Usage / Memory"),
 449         /* RESOURCES_FSM */
 450         gettext_noop("Resource Usage / Free Space Map"),
 451         /* RESOURCES_KERNEL */
 452         gettext_noop("Resource Usage / Kernel Resources"),
 453         /* WAL */
 454         gettext_noop("Write-Ahead Log"),
 455         /* WAL_SETTINGS */
 456         gettext_noop("Write-Ahead Log / Settings"),
 457         /* WAL_CHECKPOINTS */
 458         gettext_noop("Write-Ahead Log / Checkpoints"),
 459         /* QUERY_TUNING */
 460         gettext_noop("Query Tuning"),
 461         /* QUERY_TUNING_METHOD */
 462         gettext_noop("Query Tuning / Planner Method Configuration"),
 463         /* QUERY_TUNING_COST */
 464         gettext_noop("Query Tuning / Planner Cost Constants"),
 465         /* QUERY_TUNING_GEQO */
 466         gettext_noop("Query Tuning / Genetic Query Optimizer"),
 467         /* QUERY_TUNING_OTHER */
 468         gettext_noop("Query Tuning / Other Planner Options"),
 469         /* LOGGING */
 470         gettext_noop("Reporting and Logging"),
 471         /* LOGGING_WHERE */
 472         gettext_noop("Reporting and Logging / Where to Log"),
 473         /* LOGGING_WHEN */
 474         gettext_noop("Reporting and Logging / When to Log"),
 475         /* LOGGING_WHAT */
 476         gettext_noop("Reporting and Logging / What to Log"),
 477         /* STATS */
 478         gettext_noop("Statistics"),
 479         /* STATS_MONITORING */
 480         gettext_noop("Statistics / Monitoring"),
 481         /* STATS_COLLECTOR */
 482         gettext_noop("Statistics / Query and Index Statistics Collector"),
 483         /* AUTOVACUUM */
 484         gettext_noop("Autovacuum"),
 485         /* CLIENT_CONN */
 486         gettext_noop("Client Connection Defaults"),
 487         /* CLIENT_CONN_STATEMENT */
 488         gettext_noop("Client Connection Defaults / Statement Behavior"),
 489         /* CLIENT_CONN_LOCALE */
 490         gettext_noop("Client Connection Defaults / Locale and Formatting"),
 491         /* CLIENT_CONN_OTHER */
 492         gettext_noop("Client Connection Defaults / Other Defaults"),
 493         /* LOCK_MANAGEMENT */
 494         gettext_noop("Lock Management"),
 495         /* COMPAT_OPTIONS */
 496         gettext_noop("Version and Platform Compatibility"),
 497         /* COMPAT_OPTIONS_PREVIOUS */
 498         gettext_noop("Version and Platform Compatibility / Previous PostgreSQL Versions"),
 499         /* COMPAT_OPTIONS_CLIENT */
 500         gettext_noop("Version and Platform Compatibility / Other Platforms and Clients"),
 501         /* PRESET_OPTIONS */
 502         gettext_noop("Preset Options"),
 503         /* CUSTOM_OPTIONS */
 504         gettext_noop("Customized Options"),
 505         /* DEVELOPER_OPTIONS */
 506         gettext_noop("Developer Options"),
 507         /* help_config wants this array to be null-terminated */
 508         NULL
 509 };
 510
 511 /*
 512  * Displayable names for GUC variable types (enum config_type)
 513  *
 514  * Note: these strings are deliberately not localized.
 515  */
 516 const char *const config_type_names[] =
 517 {
 518          /* PGC_BOOL */ "bool",
 519          /* PGC_INT */ "integer",
 520          /* PGC_REAL */ "real",
 521          /* PGC_STRING */ "string",
 522          /* PGC_ENUM */ "enum"
 523 };
 524
 525
 526 /*
 527  * Contents of GUC tables
 528  *
 529  * See src/backend/utils/misc/README for design notes.
 530  *
 531  * TO ADD AN OPTION:
 532  *
 533  * 1. Declare a global variable of type bool, int, double, or char*
 534  *        and make use of it.
 535  *
 536  * 2. Decide at what times it's safe to set the option. See guc.h for
 537  *        details.
 538  *
 539  * 3. Decide on a name, a default value, upper and lower bounds (if
 540  *        applicable), etc.
 541  *
 542  * 4. Add a record below.
 543  *
 544  * 5. Add it to src/backend/utils/misc/postgresql.conf.sample, if
 545  *        appropriate.
 546  *
 547  * 6. Don't forget to document the option (at least in config.sgml).
 548  *
 549  * 7. If it's a new GUC_LIST option you must edit pg_dumpall.c to ensure
 550  *        it is not single quoted at dump time.
 551  */
 552
 553
 554 /******** option records follow ********/
 555
 556 static struct config_bool ConfigureNamesBool[] =
 557 {
 558         {
 559                 {"enable_seqscan", PGC_USERSET, QUERY_TUNING_METHOD,
 560                         gettext_noop("Enables the planner's use of sequential-scan plans."),
 561                         NULL
 562                 },
 563                 &enable_seqscan,
 564                 true, NULL, NULL
 565         },
 566         {
 567                 {"enable_indexscan", PGC_USERSET, QUERY_TUNING_METHOD,
 568                         gettext_noop("Enables the planner's use of index-scan plans."),
 569                         NULL
 570                 },
 571                 &enable_indexscan,
 572                 true, NULL, NULL
 573         },
 574         {
 575                 {"enable_bitmapscan", PGC_USERSET, QUERY_TUNING_METHOD,
 576                         gettext_noop("Enables the planner's use of bitmap-scan plans."),
 577                         NULL
 578                 },
 579                 &enable_bitmapscan,
 580                 true, NULL, NULL
 581         },
 582         {
 583                 {"enable_tidscan", PGC_USERSET, QUERY_TUNING_METHOD,
 584                         gettext_noop("Enables the planner's use of TID scan plans."),
 585                         NULL
 586                 },
 587                 &enable_tidscan,
 588                 true, NULL, NULL
 589         },
 590         {
 591                 {"enable_sort", PGC_USERSET, QUERY_TUNING_METHOD,
 592                         gettext_noop("Enables the planner's use of explicit sort steps."),
 593                         NULL
 594                 },
 595                 &enable_sort,
 596                 true, NULL, NULL
 597         },
 598         {
 599                 {"enable_hashagg", PGC_USERSET, QUERY_TUNING_METHOD,
 600                         gettext_noop("Enables the planner's use of hashed aggregation plans."),
 601                         NULL
 602                 },
 603                 &enable_hashagg,
 604                 true, NULL, NULL
 605         },
 606         {
 607                 {"enable_nestloop", PGC_USERSET, QUERY_TUNING_METHOD,
 608                         gettext_noop("Enables the planner's use of nested-loop join plans."),
 609                         NULL
 610                 },
 611                 &enable_nestloop,
 612                 true, NULL, NULL
 613         },
 614         {
 615                 {"enable_mergejoin", PGC_USERSET, QUERY_TUNING_METHOD,
 616                         gettext_noop("Enables the planner's use of merge join plans."),
 617                         NULL
 618                 },
 619                 &enable_mergejoin,
 620                 true, NULL, NULL
 621         },
 622         {
 623                 {"enable_hashjoin", PGC_USERSET, QUERY_TUNING_METHOD,
 624                         gettext_noop("Enables the planner's use of hash join plans."),
 625                         NULL
 626                 },
 627                 &enable_hashjoin,
 628                 true, NULL, NULL
 629         },
 630         {
 631                 {"constraint_exclusion", PGC_USERSET, QUERY_TUNING_OTHER,
 632                         gettext_noop("Enables the planner to use constraints to optimize queries."),
 633                         gettext_noop("Child table scans will be skipped if their "
 634                                            "constraints guarantee that no rows match the query.")
 635                 },
 636                 &constraint_exclusion,
 637                 false, NULL, NULL
 638         },
 639         {
 640                 {"geqo", PGC_USERSET, QUERY_TUNING_GEQO,
 641                         gettext_noop("Enables genetic query optimization."),
 642                         gettext_noop("This algorithm attempts to do planning without "
 643                                                  "exhaustive searching.")
 644                 },
 645                 &enable_geqo,
 646                 true, NULL, NULL
 647         },
 648         {
 649                 /* Not for general use --- used by SET SESSION AUTHORIZATION */
 650                 {"is_superuser", PGC_INTERNAL, UNGROUPED,
 651                         gettext_noop("Shows whether the current user is a superuser."),
 652                         NULL,
 653                         GUC_REPORT | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
 654                 },
 655                 &session_auth_is_superuser,
 656                 false, NULL, NULL
 657         },
 658         {
 659                 {"ssl", PGC_POSTMASTER, CONN_AUTH_SECURITY,
 660                         gettext_noop("Enables SSL connections."),
 661                         NULL
 662                 },
 663                 &EnableSSL,
 664                 false, assign_ssl, NULL
 665         },
 666         {
 667                 {"fsync", PGC_SIGHUP, WAL_SETTINGS,
 668                         gettext_noop("Forces synchronization of updates to disk."),
 669                         gettext_noop("The server will use the fsync() system call in several places to make "
 670                         "sure that updates are physically written to disk. This insures "
 671                                                  "that a database cluster will recover to a consistent state after "
 672                                                  "an operating system or hardware crash.")
 673                 },
 674                 &enableFsync,
 675                 true, NULL, NULL
 676         },
 677         {
 678                 {"synchronous_commit", PGC_USERSET, WAL_SETTINGS,
 679                         gettext_noop("Sets immediate fsync at commit."),
 680                         NULL
 681                 },
 682                 &XactSyncCommit,
 683                 true, NULL, NULL
 684         },
 685         {
 686                 {"zero_damaged_pages", PGC_SUSET, DEVELOPER_OPTIONS,
 687                         gettext_noop("Continues processing past damaged page headers."),
 688                         gettext_noop("Detection of a damaged page header normally causes PostgreSQL to "
 689                                 "report an error, aborting the current transaction. Setting "
 690                                                  "zero_damaged_pages to true causes the system to instead report a "
 691                                                  "warning, zero out the damaged page, and continue processing. This "
 692                                                  "behavior will destroy data, namely all the rows on the damaged page."),
 693                         GUC_NOT_IN_SAMPLE
 694                 },
 695                 &zero_damaged_pages,
 696                 false, NULL, NULL
 697         },
 698         {
 699                 {"full_page_writes", PGC_SIGHUP, WAL_SETTINGS,
 700                         gettext_noop("Writes full pages to WAL when first modified after a checkpoint."),
 701                         gettext_noop("A page write in process during an operating system crash might be "
 702                                                  "only partially written to disk.  During recovery, the row changes "
 703                           "stored in WAL are not enough to recover.  This option writes "
 704                                                  "pages when first modified after a checkpoint to WAL so full recovery "
 705                                                  "is possible.")
 706                 },
 707                 &fullPageWrites,
 708                 true, NULL, NULL
 709         },
 710         {
 711                 {"silent_mode", PGC_POSTMASTER, LOGGING_WHEN,
 712                         gettext_noop("Runs the server silently."),
 713                         gettext_noop("If this parameter is set, the server will automatically run in the "
 714                                  "background and any controlling terminals are dissociated.")
 715                 },
 716                 &SilentMode,
 717                 false, NULL, NULL
 718         },
 719         {
 720                 {"log_checkpoints", PGC_SIGHUP, LOGGING_WHAT,
 721                         gettext_noop("Logs each checkpoint."),
 722                         NULL
 723                 },
 724                 &log_checkpoints,
 725                 false, NULL, NULL
 726         },
 727         {
 728                 {"log_connections", PGC_BACKEND, LOGGING_WHAT,
 729                         gettext_noop("Logs each successful connection."),
 730                         NULL
 731                 },
 732                 &Log_connections,
 733                 false, NULL, NULL
 734         },
 735         {
 736                 {"log_disconnections", PGC_BACKEND, LOGGING_WHAT,
 737                         gettext_noop("Logs end of a session, including duration."),
 738                         NULL
 739                 },
 740                 &Log_disconnections,
 741                 false, NULL, NULL
 742         },
 743         {
 744                 {"debug_assertions", PGC_USERSET, DEVELOPER_OPTIONS,
 745                         gettext_noop("Turns on various assertion checks."),
 746                         gettext_noop("This is a debugging aid."),
 747                         GUC_NOT_IN_SAMPLE
 748                 },
 749                 &assert_enabled,
 750 #ifdef USE_ASSERT_CHECKING
 751                 true,
 752 #else
 753                 false,
 754 #endif
 755                 assign_debug_assertions, NULL
 756         },
 757         {
 758                 /* currently undocumented, so don't show in SHOW ALL */
 759                 {"exit_on_error", PGC_USERSET, UNGROUPED,
 760                         gettext_noop("No description available."),
 761                         NULL,
 762                         GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE
 763                 },
 764                 &ExitOnAnyError,
 765                 false, NULL, NULL
 766         },
 767         {
 768                 {"log_duration", PGC_SUSET, LOGGING_WHAT,
 769                         gettext_noop("Logs the duration of each completed SQL statement."),
 770                         NULL
 771                 },
 772                 &log_duration,
 773                 false, NULL, NULL
 774         },
 775         {
 776                 {"debug_print_parse", PGC_USERSET, LOGGING_WHAT,
 777                         gettext_noop("Logs each query's parse tree."),
 778                         NULL
 779                 },
 780                 &Debug_print_parse,
 781                 false, NULL, NULL
 782         },
 783         {
 784                 {"debug_print_rewritten", PGC_USERSET, LOGGING_WHAT,
 785                         gettext_noop("Logs each query's rewritten parse tree."),
 786                         NULL
 787                 },
 788                 &Debug_print_rewritten,
 789                 false, NULL, NULL
 790         },
 791         {
 792                 {"debug_print_plan", PGC_USERSET, LOGGING_WHAT,
 793                         gettext_noop("Logs each query's execution plan."),
 794                         NULL
 795                 },
 796                 &Debug_print_plan,
 797                 false, NULL, NULL
 798         },
 799         {
 800                 {"debug_pretty_print", PGC_USERSET, LOGGING_WHAT,
 801                         gettext_noop("Indents parse and plan tree displays."),
 802                         NULL
 803                 },
 804                 &Debug_pretty_print,
 805                 true, NULL, NULL
 806         },
 807         {
 808                 {"log_parser_stats", PGC_SUSET, STATS_MONITORING,
 809                         gettext_noop("Writes parser performance statistics to the server log."),
 810                         NULL
 811                 },
 812                 &log_parser_stats,
 813                 false, assign_stage_log_stats, NULL
 814         },
 815         {
 816                 {"log_planner_stats", PGC_SUSET, STATS_MONITORING,
 817                         gettext_noop("Writes planner performance statistics to the server log."),
 818                         NULL
 819                 },
 820                 &log_planner_stats,
 821                 false, assign_stage_log_stats, NULL
 822         },
 823         {
 824                 {"log_executor_stats", PGC_SUSET, STATS_MONITORING,
 825                         gettext_noop("Writes executor performance statistics to the server log."),
 826                         NULL
 827                 },
 828                 &log_executor_stats,
 829                 false, assign_stage_log_stats, NULL
 830         },
 831         {
 832                 {"log_statement_stats", PGC_SUSET, STATS_MONITORING,
 833                         gettext_noop("Writes cumulative performance statistics to the server log."),
 834                         NULL
 835                 },
 836                 &log_statement_stats,
 837                 false, assign_log_stats, NULL
 838         },
 839 #ifdef BTREE_BUILD_STATS
 840         {
 841                 {"log_btree_build_stats", PGC_SUSET, DEVELOPER_OPTIONS,
 842                         gettext_noop("No description available."),
 843                         NULL,
 844                         GUC_NOT_IN_SAMPLE
 845                 },
 846                 &log_btree_build_stats,
 847                 false, NULL, NULL
 848         },
 849 #endif
 850
 851         {
 852                 {"track_activities", PGC_SUSET, STATS_COLLECTOR,
 853                         gettext_noop("Collects information about executing commands."),
 854                         gettext_noop("Enables the collection of information on the currently "
 855                                                  "executing command of each session, along with "
 856                                                  "the time at which that command began execution.")
 857                 },
 858                 &pgstat_track_activities,
 859                 true, NULL, NULL
 860         },
 861         {
 862                 {"track_counts", PGC_SUSET, STATS_COLLECTOR,
 863                         gettext_noop("Collects statistics on database activity."),
 864                         NULL
 865                 },
 866                 &pgstat_track_counts,
 867                 true, NULL, NULL
 868         },
 869
 870         {
 871                 {"update_process_title", PGC_SUSET, STATS_COLLECTOR,
 872                         gettext_noop("Updates the process title to show the active SQL command."),
 873                         gettext_noop("Enables updating of the process title every time a new SQL command is received by the server.")
 874                 },
 875                 &update_process_title,
 876                 true, NULL, NULL
 877         },
 878
 879         {
 880                 {"autovacuum", PGC_SIGHUP, AUTOVACUUM,
 881                         gettext_noop("Starts the autovacuum subprocess."),
 882                         NULL
 883                 },
 884                 &autovacuum_start_daemon,
 885                 true, NULL, NULL
 886         },
 887
 888         {
 889                 {"trace_notify", PGC_USERSET, DEVELOPER_OPTIONS,
 890                         gettext_noop("Generates debugging output for LISTEN and NOTIFY."),
 891                         NULL,
 892                         GUC_NOT_IN_SAMPLE
 893                 },
 894                 &Trace_notify,
 895                 false, NULL, NULL
 896         },
 897
 898 #ifdef LOCK_DEBUG
 899         {
 900                 {"trace_locks", PGC_SUSET, DEVELOPER_OPTIONS,
 901                         gettext_noop("No description available."),
 902                         NULL,
 903                         GUC_NOT_IN_SAMPLE
 904                 },
 905                 &Trace_locks,
 906                 false, NULL, NULL
 907         },
 908         {
 909                 {"trace_userlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 910                         gettext_noop("No description available."),
 911                         NULL,
 912                         GUC_NOT_IN_SAMPLE
 913                 },
 914                 &Trace_userlocks,
 915                 false, NULL, NULL
 916         },
 917         {
 918                 {"trace_lwlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 919                         gettext_noop("No description available."),
 920                         NULL,
 921                         GUC_NOT_IN_SAMPLE
 922                 },
 923                 &Trace_lwlocks,
 924                 false, NULL, NULL
 925         },
 926         {
 927                 {"debug_deadlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 928                         gettext_noop("No description available."),
 929                         NULL,
 930                         GUC_NOT_IN_SAMPLE
 931                 },
 932                 &Debug_deadlocks,
 933                 false, NULL, NULL
 934         },
 935 #endif
 936
 937         {
 938                 {"log_lock_waits", PGC_SUSET, LOGGING_WHAT,
 939                         gettext_noop("Logs long lock waits."),
 940                         NULL
 941                 },
 942                 &log_lock_waits,
 943                 false, NULL, NULL
 944         },
 945
 946         {
 947                 {"log_hostname", PGC_SIGHUP, LOGGING_WHAT,
 948                         gettext_noop("Logs the host name in the connection logs."),
 949                         gettext_noop("By default, connection logs only show the IP address "
 950                                                  "of the connecting host. If you want them to show the host name you "
 951                           "can turn this on, but depending on your host name resolution "
 952                            "setup it might impose a non-negligible performance penalty.")
 953                 },
 954                 &log_hostname,
 955                 false, NULL, NULL
 956         },
 957         {
 958                 {"sql_inheritance", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
 959                         gettext_noop("Causes subtables to be included by default in various commands."),
 960                         NULL
 961                 },
 962                 &SQL_inheritance,
 963                 true, NULL, NULL
 964         },
 965         {
 966                 {"password_encryption", PGC_USERSET, CONN_AUTH_SECURITY,
 967                         gettext_noop("Encrypt passwords."),
 968                         gettext_noop("When a password is specified in CREATE USER or "
 969                            "ALTER USER without writing either ENCRYPTED or UNENCRYPTED, "
 970                                                  "this parameter determines whether the password is to be encrypted.")
 971                 },
 972                 &Password_encryption,
 973                 true, NULL, NULL
 974         },
 975         {
 976                 {"transform_null_equals", PGC_USERSET, COMPAT_OPTIONS_CLIENT,
 977                         gettext_noop("Treats \"expr=NULL\" as \"expr IS NULL\"."),
 978                         gettext_noop("When turned on, expressions of the form expr = NULL "
 979                            "(or NULL = expr) are treated as expr IS NULL, that is, they "
 980                                 "return true if expr evaluates to the null value, and false "
 981                            "otherwise. The correct behavior of expr = NULL is to always "
 982                                                  "return null (unknown).")
 983                 },
 984                 &Transform_null_equals,
 985                 false, NULL, NULL
 986         },
 987         {
 988                 {"db_user_namespace", PGC_SIGHUP, CONN_AUTH_SECURITY,
 989                         gettext_noop("Enables per-database user names."),
 990                         NULL
 991                 },
 992                 &Db_user_namespace,
 993                 false, NULL, NULL
 994         },
 995         {
 996                 /* only here for backwards compatibility */
 997                 {"autocommit", PGC_USERSET, CLIENT_CONN_STATEMENT,
 998                         gettext_noop("This parameter doesn't do anything."),
 999                         gettext_noop("It's just here so that we won't choke on SET AUTOCOMMIT TO ON from 7.3-vintage clients."),
1000                         GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE
1001                 },
1002                 &phony_autocommit,
1003                 true, assign_phony_autocommit, NULL
1004         },
1005         {
1006                 {"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
1007                         gettext_noop("Sets the default read-only status of new transactions."),
1008                         NULL
1009                 },
1010                 &DefaultXactReadOnly,
1011                 false, NULL, NULL
1012         },
1013         {
1014                 {"transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
1015                         gettext_noop("Sets the current transaction's read-only status."),
1016                         NULL,
1017                         GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1018                 },
1019                 &XactReadOnly,
1020                 false, assign_transaction_read_only, NULL
1021         },
1022         {
1023                 {"add_missing_from", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1024                         gettext_noop("Automatically adds missing table references to FROM clauses."),
1025                         NULL
1026                 },
1027                 &add_missing_from,
1028                 false, NULL, NULL
1029         },
1030         {
1031                 {"check_function_bodies", PGC_USERSET, CLIENT_CONN_STATEMENT,
1032                         gettext_noop("Check function bodies during CREATE FUNCTION."),
1033                         NULL
1034                 },
1035                 &check_function_bodies,
1036                 true, NULL, NULL
1037         },
1038         {
1039                 {"array_nulls", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1040                         gettext_noop("Enable input of NULL elements in arrays."),
1041                         gettext_noop("When turned on, unquoted NULL in an array input "
1042                                                  "value means a null value; "
1043                                                  "otherwise it is taken literally.")
1044                 },
1045                 &Array_nulls,
1046                 true, NULL, NULL
1047         },
1048         {
1049                 {"default_with_oids", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1050                         gettext_noop("Create new tables with OIDs by default."),
1051                         NULL
1052                 },
1053                 &default_with_oids,
1054                 false, NULL, NULL
1055         },
1056         {
1057                 {"logging_collector", PGC_POSTMASTER, LOGGING_WHERE,
1058                         gettext_noop("Start a subprocess to capture stderr output and/or csvlogs into log files."),
1059                         NULL
1060                 },
1061                 &Logging_collector,
1062                 false, NULL, NULL
1063         },
1064         {
1065                 {"log_truncate_on_rotation", PGC_SIGHUP, LOGGING_WHERE,
1066                         gettext_noop("Truncate existing log files of same name during log rotation."),
1067                         NULL
1068                 },
1069                 &Log_truncate_on_rotation,
1070                 false, NULL, NULL
1071         },
1072
1073 #ifdef TRACE_SORT
1074         {
1075                 {"trace_sort", PGC_USERSET, DEVELOPER_OPTIONS,
1076                         gettext_noop("Emit information about resource usage in sorting."),
1077                         NULL,
1078                         GUC_NOT_IN_SAMPLE
1079                 },
1080                 &trace_sort,
1081                 false, NULL, NULL
1082         },
1083 #endif
1084
1085 #ifdef TRACE_SYNCSCAN
1086         /* this is undocumented because not exposed in a standard build */
1087         {
1088                 {"trace_syncscan", PGC_USERSET, DEVELOPER_OPTIONS,
1089                         gettext_noop("Generate debugging output for synchronized scanning."),
1090                         NULL,
1091                         GUC_NOT_IN_SAMPLE
1092                 },
1093                 &trace_syncscan,
1094                 false, NULL, NULL
1095         },
1096 #endif
1097
1098 #ifdef DEBUG_BOUNDED_SORT
1099         /* this is undocumented because not exposed in a standard build */
1100         {
1101                 {
1102                         "optimize_bounded_sort", PGC_USERSET, QUERY_TUNING_METHOD,
1103                         gettext_noop("Enable bounded sorting using heap sort."),
1104                         NULL,
1105                         GUC_NOT_IN_SAMPLE
1106                 },
1107                 &optimize_bounded_sort,
1108                 true, NULL, NULL
1109         },
1110 #endif
1111
1112 #ifdef WAL_DEBUG
1113         {
1114                 {"wal_debug", PGC_SUSET, DEVELOPER_OPTIONS,
1115                         gettext_noop("Emit WAL-related debugging output."),
1116                         NULL,
1117                         GUC_NOT_IN_SAMPLE
1118                 },
1119                 &XLOG_DEBUG,
1120                 false, NULL, NULL
1121         },
1122 #endif
1123
1124         {
1125                 {"integer_datetimes", PGC_INTERNAL, PRESET_OPTIONS,
1126                         gettext_noop("Datetimes are integer based."),
1127                         NULL,
1128                         GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1129                 },
1130                 &integer_datetimes,
1131 #ifdef HAVE_INT64_TIMESTAMP
1132                 true, NULL, NULL
1133 #else
1134                 false, NULL, NULL
1135 #endif
1136         },
1137
1138         {
1139                 {"krb_caseins_users", PGC_POSTMASTER, CONN_AUTH_SECURITY,
1140                         gettext_noop("Sets whether Kerberos and GSSAPI user names should be treated as case-insensitive."),
1141                         NULL
1142                 },
1143                 &pg_krb_caseins_users,
1144                 false, NULL, NULL
1145         },
1146
1147         {
1148                 {"escape_string_warning", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1149                         gettext_noop("Warn about backslash escapes in ordinary string literals."),
1150                         NULL
1151                 },
1152                 &escape_string_warning,
1153                 true, NULL, NULL
1154         },
1155
1156         {
1157                 {"standard_conforming_strings", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1158                         gettext_noop("Causes '...' strings to treat backslashes literally."),
1159                         NULL,
1160                         GUC_REPORT
1161                 },
1162                 &standard_conforming_strings,
1163                 false, NULL, NULL
1164         },
1165
1166         {
1167                 {"synchronize_seqscans", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1168                         gettext_noop("Enable synchronized sequential scans."),
1169                         NULL
1170                 },
1171                 &synchronize_seqscans,
1172                 true, NULL, NULL
1173         },
1174
1175         {
1176                 {"archive_mode", PGC_POSTMASTER, WAL_SETTINGS,
1177                         gettext_noop("Allows archiving of WAL files using archive_command."),
1178                         NULL
1179                 },
1180                 &XLogArchiveMode,
1181                 false, NULL, NULL
1182         },
1183
1184         {
1185                 {"allow_system_table_mods", PGC_POSTMASTER, DEVELOPER_OPTIONS,
1186                         gettext_noop("Allows modifications of the structure of system tables."),
1187                         NULL,
1188                         GUC_NOT_IN_SAMPLE
1189                 },
1190                 &allowSystemTableMods,
1191                 false, NULL, NULL
1192         },
1193
1194         {
1195                 {"ignore_system_indexes", PGC_BACKEND, DEVELOPER_OPTIONS,
1196                         gettext_noop("Disables reading from system indexes."),
1197                         gettext_noop("It does not prevent updating the indexes, so it is safe "
1198                                                  "to use.  The worst consequence is slowness."),
1199                         GUC_NOT_IN_SAMPLE
1200                 },
1201                 &IgnoreSystemIndexes,
1202                 false, NULL, NULL
1203         },
1204
1205         /* End-of-list marker */
1206         {
1207                 {NULL, 0, 0, NULL, NULL}, NULL, false, NULL, NULL
1208         }
1209 };
1210
1211
1212 static struct config_int ConfigureNamesInt[] =
1213 {
1214         {
1215                 {"archive_timeout", PGC_SIGHUP, WAL_SETTINGS,
1216                         gettext_noop("Forces a switch to the next xlog file if a "
1217                                                  "new file has not been started within N seconds."),
1218                         NULL,
1219                         GUC_UNIT_S
1220                 },
1221                 &XLogArchiveTimeout,
1222                 0, 0, INT_MAX, NULL, NULL
1223         },
1224         {
1225                 {"post_auth_delay", PGC_BACKEND, DEVELOPER_OPTIONS,
1226                         gettext_noop("Waits N seconds on connection startup after authentication."),
1227                         gettext_noop("This allows attaching a debugger to the process."),
1228                         GUC_NOT_IN_SAMPLE | GUC_UNIT_S
1229                 },
1230                 &PostAuthDelay,
1231                 0, 0, INT_MAX, NULL, NULL
1232         },
1233         {
1234                 {"default_statistics_target", PGC_USERSET, QUERY_TUNING_OTHER,
1235                         gettext_noop("Sets the default statistics target."),
1236                         gettext_noop("This applies to table columns that have not had a "
1237                                 "column-specific target set via ALTER TABLE SET STATISTICS.")
1238                 },
1239                 &default_statistics_target,
1240                 10, 1, 1000, NULL, NULL
1241         },
1242         {
1243                 {"from_collapse_limit", PGC_USERSET, QUERY_TUNING_OTHER,
1244                         gettext_noop("Sets the FROM-list size beyond which subqueries "
1245                                                  "are not collapsed."),
1246                         gettext_noop("The planner will merge subqueries into upper "
1247                                 "queries if the resulting FROM list would have no more than "
1248                                                  "this many items.")
1249                 },
1250                 &from_collapse_limit,
1251                 8, 1, INT_MAX, NULL, NULL
1252         },
1253         {
1254                 {"join_collapse_limit", PGC_USERSET, QUERY_TUNING_OTHER,
1255                         gettext_noop("Sets the FROM-list size beyond which JOIN "
1256                                                  "constructs are not flattened."),
1257                         gettext_noop("The planner will flatten explicit JOIN "
1258                                                  "constructs into lists of FROM items whenever a "
1259                                                  "list of no more than this many items would result.")
1260                 },
1261                 &join_collapse_limit,
1262                 8, 1, INT_MAX, NULL, NULL
1263         },
1264         {
1265                 {"geqo_threshold", PGC_USERSET, QUERY_TUNING_GEQO,
1266                         gettext_noop("Sets the threshold of FROM items beyond which GEQO is used."),
1267                         NULL
1268                 },
1269                 &geqo_threshold,
1270                 12, 2, INT_MAX, NULL, NULL
1271         },
1272         {
1273                 {"geqo_effort", PGC_USERSET, QUERY_TUNING_GEQO,
1274                         gettext_noop("GEQO: effort is used to set the default for other GEQO parameters."),
1275                         NULL
1276                 },
1277                 &Geqo_effort,
1278                 DEFAULT_GEQO_EFFORT, MIN_GEQO_EFFORT, MAX_GEQO_EFFORT, NULL, NULL
1279         },
1280         {
1281                 {"geqo_pool_size", PGC_USERSET, QUERY_TUNING_GEQO,
1282                         gettext_noop("GEQO: number of individuals in the population."),
1283                         gettext_noop("Zero selects a suitable default value.")
1284                 },
1285                 &Geqo_pool_size,
1286                 0, 0, INT_MAX, NULL, NULL
1287         },
1288         {
1289                 {"geqo_generations", PGC_USERSET, QUERY_TUNING_GEQO,
1290                         gettext_noop("GEQO: number of iterations of the algorithm."),
1291                         gettext_noop("Zero selects a suitable default value.")
1292                 },
1293                 &Geqo_generations,
1294                 0, 0, INT_MAX, NULL, NULL
1295         },
1296
1297         {
1298                 /* This is PGC_SIGHUP so all backends have the same value. */
1299                 {"deadlock_timeout", PGC_SIGHUP, LOCK_MANAGEMENT,
1300                         gettext_noop("Sets the time to wait on a lock before checking for deadlock."),
1301                         NULL,
1302                         GUC_UNIT_MS
1303                 },
1304                 &DeadlockTimeout,
1305                 1000, 1, INT_MAX / 1000, NULL, NULL
1306         },
1307
1308         /*
1309          * Note: MaxBackends is limited to INT_MAX/4 because some places compute
1310          * 4*MaxBackends without any overflow check.  This check is made in
1311          * assign_maxconnections, since MaxBackends is computed as MaxConnections
1312          * plus autovacuum_max_workers.
1313          *
1314          * Likewise we have to limit NBuffers to INT_MAX/2.
1315          */
1316         {
1317                 {"max_connections", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1318                         gettext_noop("Sets the maximum number of concurrent connections."),
1319                         NULL
1320                 },
1321                 &MaxConnections,
1322                 100, 1, INT_MAX / 4, assign_maxconnections, NULL
1323         },
1324
1325         {
1326                 {"superuser_reserved_connections", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1327                         gettext_noop("Sets the number of connection slots reserved for superusers."),
1328                         NULL
1329                 },
1330                 &ReservedBackends,
1331                 3, 0, INT_MAX / 4, NULL, NULL
1332         },
1333
1334         {
1335                 {"shared_buffers", PGC_POSTMASTER, RESOURCES_MEM,
1336                         gettext_noop("Sets the number of shared memory buffers used by the server."),
1337                         NULL,
1338                         GUC_UNIT_BLOCKS
1339                 },
1340                 &NBuffers,
1341                 1024, 16, INT_MAX / 2, NULL, NULL
1342         },
1343
1344         {
1345                 {"temp_buffers", PGC_USERSET, RESOURCES_MEM,
1346                         gettext_noop("Sets the maximum number of temporary buffers used by each session."),
1347                         NULL,
1348                         GUC_UNIT_BLOCKS
1349                 },
1350                 &num_temp_buffers,
1351                 1024, 100, INT_MAX / 2, NULL, show_num_temp_buffers
1352         },
1353
1354         {
1355                 {"port", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1356                         gettext_noop("Sets the TCP port the server listens on."),
1357                         NULL
1358                 },
1359                 &PostPortNumber,
1360                 DEF_PGPORT, 1, 65535, NULL, NULL
1361         },
1362
1363         {
1364                 {"unix_socket_permissions", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1365                         gettext_noop("Sets the access permissions of the Unix-domain socket."),
1366                         gettext_noop("Unix-domain sockets use the usual Unix file system "
1367                                                  "permission set. The parameter value is expected to be a numeric mode "
1368                                                  "specification in the form accepted by the chmod and umask system "
1369                                                  "calls. (To use the customary octal format the number must start with "
1370                                                  "a 0 (zero).)")
1371                 },
1372                 &Unix_socket_permissions,
1373                 0777, 0000, 0777, NULL, NULL
1374         },
1375
1376         {
1377                 {"work_mem", PGC_USERSET, RESOURCES_MEM,
1378                         gettext_noop("Sets the maximum memory to be used for query workspaces."),
1379                         gettext_noop("This much memory can be used by each internal "
1380                                                  "sort operation and hash table before switching to "
1381                                                  "temporary disk files."),
1382                         GUC_UNIT_KB
1383                 },
1384                 &work_mem,
1385                 1024, 64, MAX_KILOBYTES, NULL, NULL
1386         },
1387
1388         {
1389                 {"maintenance_work_mem", PGC_USERSET, RESOURCES_MEM,
1390                         gettext_noop("Sets the maximum memory to be used for maintenance operations."),
1391                         gettext_noop("This includes operations such as VACUUM and CREATE INDEX."),
1392                         GUC_UNIT_KB
1393                 },
1394                 &maintenance_work_mem,
1395                 16384, 1024, MAX_KILOBYTES, NULL, NULL
1396         },
1397
1398         {
1399                 {"max_stack_depth", PGC_SUSET, RESOURCES_MEM,
1400                         gettext_noop("Sets the maximum stack depth, in kilobytes."),
1401                         NULL,
1402                         GUC_UNIT_KB
1403                 },
1404                 &max_stack_depth,
1405                 100, 100, MAX_KILOBYTES, assign_max_stack_depth, NULL
1406         },
1407
1408         {
1409                 {"vacuum_cost_page_hit", PGC_USERSET, RESOURCES,
1410                         gettext_noop("Vacuum cost for a page found in the buffer cache."),
1411                         NULL
1412                 },
1413                 &VacuumCostPageHit,
1414                 1, 0, 10000, NULL, NULL
1415         },
1416
1417         {
1418                 {"vacuum_cost_page_miss", PGC_USERSET, RESOURCES,
1419                         gettext_noop("Vacuum cost for a page not found in the buffer cache."),
1420                         NULL
1421                 },
1422                 &VacuumCostPageMiss,
1423                 10, 0, 10000, NULL, NULL
1424         },
1425
1426         {
1427                 {"vacuum_cost_page_dirty", PGC_USERSET, RESOURCES,
1428                         gettext_noop("Vacuum cost for a page dirtied by vacuum."),
1429                         NULL
1430                 },
1431                 &VacuumCostPageDirty,
1432                 20, 0, 10000, NULL, NULL
1433         },
1434
1435         {
1436                 {"vacuum_cost_limit", PGC_USERSET, RESOURCES,
1437                         gettext_noop("Vacuum cost amount available before napping."),
1438                         NULL
1439                 },
1440                 &VacuumCostLimit,
1441                 200, 1, 10000, NULL, NULL
1442         },
1443
1444         {
1445                 {"vacuum_cost_delay", PGC_USERSET, RESOURCES,
1446                         gettext_noop("Vacuum cost delay in milliseconds."),
1447                         NULL,
1448                         GUC_UNIT_MS
1449                 },
1450                 &VacuumCostDelay,
1451                 0, 0, 1000, NULL, NULL
1452         },
1453
1454         {
1455                 {"autovacuum_vacuum_cost_delay", PGC_SIGHUP, AUTOVACUUM,
1456                         gettext_noop("Vacuum cost delay in milliseconds, for autovacuum."),
1457                         NULL,
1458                         GUC_UNIT_MS
1459                 },
1460                 &autovacuum_vac_cost_delay,
1461                 20, -1, 1000, NULL, NULL
1462         },
1463
1464         {
1465                 {"autovacuum_vacuum_cost_limit", PGC_SIGHUP, AUTOVACUUM,
1466                         gettext_noop("Vacuum cost amount available before napping, for autovacuum."),
1467                         NULL
1468                 },
1469                 &autovacuum_vac_cost_limit,
1470                 -1, -1, 10000, NULL, NULL
1471         },
1472
1473         {
1474                 {"max_files_per_process", PGC_POSTMASTER, RESOURCES_KERNEL,
1475                         gettext_noop("Sets the maximum number of simultaneously open files for each server process."),
1476                         NULL
1477                 },
1478                 &max_files_per_process,
1479                 1000, 25, INT_MAX, NULL, NULL
1480         },
1481
1482         {
1483                 {"max_prepared_transactions", PGC_POSTMASTER, RESOURCES,
1484                         gettext_noop("Sets the maximum number of simultaneously prepared transactions."),
1485                         NULL
1486                 },
1487                 &max_prepared_xacts,
1488                 5, 0, INT_MAX, NULL, NULL
1489         },
1490
1491 #ifdef LOCK_DEBUG
1492         {
1493                 {"trace_lock_oidmin", PGC_SUSET, DEVELOPER_OPTIONS,
1494                         gettext_noop("No description available."),
1495                         NULL,
1496                         GUC_NOT_IN_SAMPLE
1497                 },
1498                 &Trace_lock_oidmin,
1499                 FirstNormalObjectId, 0, INT_MAX, NULL, NULL
1500         },
1501         {
1502                 {"trace_lock_table", PGC_SUSET, DEVELOPER_OPTIONS,
1503                         gettext_noop("No description available."),
1504                         NULL,
1505                         GUC_NOT_IN_SAMPLE
1506                 },
1507                 &Trace_lock_table,
1508                 0, 0, INT_MAX, NULL, NULL
1509         },
1510 #endif
1511
1512         {
1513                 {"statement_timeout", PGC_USERSET, CLIENT_CONN_STATEMENT,
1514                         gettext_noop("Sets the maximum allowed duration of any statement."),
1515                         gettext_noop("A value of 0 turns off the timeout."),
1516                         GUC_UNIT_MS
1517                 },
1518                 &StatementTimeout,
1519                 0, 0, INT_MAX, NULL, NULL
1520         },
1521
1522         {
1523                 {"vacuum_freeze_min_age", PGC_USERSET, CLIENT_CONN_STATEMENT,
1524                         gettext_noop("Minimum age at which VACUUM should freeze a table row."),
1525                         NULL
1526                 },
1527                 &vacuum_freeze_min_age,
1528                 100000000, 0, 1000000000, NULL, NULL
1529         },
1530
1531         {
1532                 {"max_fsm_relations", PGC_POSTMASTER, RESOURCES_FSM,
1533                         gettext_noop("Sets the maximum number of tables and indexes for which free space is tracked."),
1534                         NULL
1535                 },
1536                 &MaxFSMRelations,
1537                 1000, 100, INT_MAX, NULL, NULL
1538         },
1539         {
1540                 {"max_fsm_pages", PGC_POSTMASTER, RESOURCES_FSM,
1541                         gettext_noop("Sets the maximum number of disk pages for which free space is tracked."),
1542                         NULL
1543                 },
1544                 &MaxFSMPages,
1545                 20000, 1000, INT_MAX, NULL, NULL
1546         },
1547
1548         {
1549                 {"max_locks_per_transaction", PGC_POSTMASTER, LOCK_MANAGEMENT,
1550                         gettext_noop("Sets the maximum number of locks per transaction."),
1551                         gettext_noop("The shared lock table is sized on the assumption that "
1552                           "at most max_locks_per_transaction * max_connections distinct "
1553                                                  "objects will need to be locked at any one time.")
1554                 },
1555                 &max_locks_per_xact,
1556                 64, 10, INT_MAX, NULL, NULL
1557         },
1558
1559         {
1560                 {"authentication_timeout", PGC_SIGHUP, CONN_AUTH_SECURITY,
1561                         gettext_noop("Sets the maximum allowed time to complete client authentication."),
1562                         NULL,
1563                         GUC_UNIT_S
1564                 },
1565                 &AuthenticationTimeout,
1566                 60, 1, 600, NULL, NULL
1567         },
1568
1569         {
1570                 /* Not for general use */
1571                 {"pre_auth_delay", PGC_SIGHUP, DEVELOPER_OPTIONS,
1572                         gettext_noop("Waits N seconds on connection startup before authentication."),
1573                         gettext_noop("This allows attaching a debugger to the process."),
1574                         GUC_NOT_IN_SAMPLE | GUC_UNIT_S
1575                 },
1576                 &PreAuthDelay,
1577                 0, 0, 60, NULL, NULL
1578         },
1579
1580         {
1581                 {"checkpoint_segments", PGC_SIGHUP, WAL_CHECKPOINTS,
1582                         gettext_noop("Sets the maximum distance in log segments between automatic WAL checkpoints."),
1583                         NULL
1584                 },
1585                 &CheckPointSegments,
1586                 3, 1, INT_MAX, NULL, NULL
1587         },
1588
1589         {
1590                 {"checkpoint_timeout", PGC_SIGHUP, WAL_CHECKPOINTS,
1591                         gettext_noop("Sets the maximum time between automatic WAL checkpoints."),
1592                         NULL,
1593                         GUC_UNIT_S
1594                 },
1595                 &CheckPointTimeout,
1596                 300, 30, 3600, NULL, NULL
1597         },
1598
1599         {
1600                 {"checkpoint_warning", PGC_SIGHUP, WAL_CHECKPOINTS,
1601                         gettext_noop("Enables warnings if checkpoint segments are filled more "
1602                                                  "frequently than this."),
1603                         gettext_noop("Write a message to the server log if checkpoints "
1604                         "caused by the filling of checkpoint segment files happens more "
1605                                                  "frequently than this number of seconds. Zero turns off the warning."),
1606                         GUC_UNIT_S
1607                 },
1608                 &CheckPointWarning,
1609                 30, 0, INT_MAX, NULL, NULL
1610         },
1611
1612         {
1613                 {"wal_buffers", PGC_POSTMASTER, WAL_SETTINGS,
1614                         gettext_noop("Sets the number of disk-page buffers in shared memory for WAL."),
1615                         NULL,
1616                         GUC_UNIT_XBLOCKS
1617                 },
1618                 &XLOGbuffers,
1619                 8, 4, INT_MAX, NULL, NULL
1620         },
1621
1622         {
1623                 {"wal_writer_delay", PGC_SIGHUP, WAL_SETTINGS,
1624                         gettext_noop("WAL writer sleep time between WAL flushes."),
1625                         NULL,
1626                         GUC_UNIT_MS
1627                 },
1628                 &WalWriterDelay,
1629                 200, 1, 10000, NULL, NULL
1630         },
1631
1632         {
1633                 {"commit_delay", PGC_USERSET, WAL_SETTINGS,
1634                         gettext_noop("Sets the delay in microseconds between transaction commit and "
1635                                                  "flushing WAL to disk."),
1636                         NULL
1637                 },
1638                 &CommitDelay,
1639                 0, 0, 100000, NULL, NULL
1640         },
1641
1642         {
1643                 {"commit_siblings", PGC_USERSET, WAL_SETTINGS,
1644                         gettext_noop("Sets the minimum concurrent open transactions before performing "
1645                                                  "commit_delay."),
1646                         NULL
1647                 },
1648                 &CommitSiblings,
1649                 5, 1, 1000, NULL, NULL
1650         },
1651
1652         {
1653                 {"extra_float_digits", PGC_USERSET, CLIENT_CONN_LOCALE,
1654                         gettext_noop("Sets the number of digits displayed for floating-point values."),
1655                         gettext_noop("This affects real, double precision, and geometric data types. "
1656                          "The parameter value is added to the standard number of digits "
1657                                                  "(FLT_DIG or DBL_DIG as appropriate).")
1658                 },
1659                 &extra_float_digits,
1660                 0, -15, 2, NULL, NULL
1661         },
1662
1663         {
1664                 {"log_min_duration_statement", PGC_SUSET, LOGGING_WHEN,
1665                         gettext_noop("Sets the minimum execution time above which "
1666                                                  "statements will be logged."),
1667                         gettext_noop("Zero prints all queries. -1 turns this feature off."),
1668                         GUC_UNIT_MS
1669                 },
1670                 &log_min_duration_statement,
1671                 -1, -1, INT_MAX / 1000, NULL, NULL
1672         },
1673
1674         {
1675                 {"log_autovacuum_min_duration", PGC_SIGHUP, LOGGING_WHAT,
1676                         gettext_noop("Sets the minimum execution time above which "
1677                                                  "autovacuum actions will be logged."),
1678                         gettext_noop("Zero prints all actions. -1 turns autovacuum logging off."),
1679                         GUC_UNIT_MS
1680                 },
1681                 &Log_autovacuum_min_duration,
1682                 -1, -1, INT_MAX / 1000, NULL, NULL
1683         },
1684
1685         {
1686                 {"bgwriter_delay", PGC_SIGHUP, RESOURCES,
1687                         gettext_noop("Background writer sleep time between rounds."),
1688                         NULL,
1689                         GUC_UNIT_MS
1690                 },
1691                 &BgWriterDelay,
1692                 200, 10, 10000, NULL, NULL
1693         },
1694
1695         {
1696                 {"bgwriter_lru_maxpages", PGC_SIGHUP, RESOURCES,
1697                         gettext_noop("Background writer maximum number of LRU pages to flush per round."),
1698                         NULL
1699                 },
1700                 &bgwriter_lru_maxpages,
1701                 100, 0, 1000, NULL, NULL
1702         },
1703
1704         {
1705                 {"log_rotation_age", PGC_SIGHUP, LOGGING_WHERE,
1706                         gettext_noop("Automatic log file rotation will occur after N minutes."),
1707                         NULL,
1708                         GUC_UNIT_MIN
1709                 },
1710                 &Log_RotationAge,
1711                 HOURS_PER_DAY * MINS_PER_HOUR, 0, INT_MAX / MINS_PER_HOUR, NULL, NULL
1712         },
1713
1714         {
1715                 {"log_rotation_size", PGC_SIGHUP, LOGGING_WHERE,
1716                         gettext_noop("Automatic log file rotation will occur after N kilobytes."),
1717                         NULL,
1718                         GUC_UNIT_KB
1719                 },
1720                 &Log_RotationSize,
1721                 10 * 1024, 0, INT_MAX / 1024, NULL, NULL
1722         },
1723
1724         {
1725                 {"max_function_args", PGC_INTERNAL, PRESET_OPTIONS,
1726                         gettext_noop("Shows the maximum number of function arguments."),
1727                         NULL,
1728                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1729                 },
1730                 &max_function_args,
1731                 FUNC_MAX_ARGS, FUNC_MAX_ARGS, FUNC_MAX_ARGS, NULL, NULL
1732         },
1733
1734         {
1735                 {"max_index_keys", PGC_INTERNAL, PRESET_OPTIONS,
1736                         gettext_noop("Shows the maximum number of index keys."),
1737                         NULL,
1738                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1739                 },
1740                 &max_index_keys,
1741                 INDEX_MAX_KEYS, INDEX_MAX_KEYS, INDEX_MAX_KEYS, NULL, NULL
1742         },
1743
1744         {
1745                 {"max_identifier_length", PGC_INTERNAL, PRESET_OPTIONS,
1746                         gettext_noop("Shows the maximum identifier length."),
1747                         NULL,
1748                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1749                 },
1750                 &max_identifier_length,
1751                 NAMEDATALEN - 1, NAMEDATALEN - 1, NAMEDATALEN - 1, NULL, NULL
1752         },
1753
1754         {
1755                 {"block_size", PGC_INTERNAL, PRESET_OPTIONS,
1756                         gettext_noop("Shows the size of a disk block."),
1757                         NULL,
1758                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1759                 },
1760                 &block_size,
1761                 BLCKSZ, BLCKSZ, BLCKSZ, NULL, NULL
1762         },
1763
1764         {
1765                 {"segment_size", PGC_INTERNAL, PRESET_OPTIONS,
1766                     gettext_noop("Shows the number of pages per disk file."),
1767                     NULL,
1768                     GUC_UNIT_BLOCKS | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1769                 },
1770                 &segment_size,
1771                 RELSEG_SIZE, RELSEG_SIZE, RELSEG_SIZE, NULL, NULL
1772         },
1773
1774         {
1775                 {"wal_block_size", PGC_INTERNAL, PRESET_OPTIONS,
1776                         gettext_noop("Shows the block size in the write ahead log."),
1777                         NULL,
1778                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1779                 },
1780                 &wal_block_size,
1781                 XLOG_BLCKSZ, XLOG_BLCKSZ, XLOG_BLCKSZ, NULL, NULL
1782         },
1783
1784         {
1785                 {"wal_segment_size", PGC_INTERNAL, PRESET_OPTIONS,
1786                         gettext_noop("Shows the number of pages per write ahead log segment."),
1787                         NULL,
1788                         GUC_UNIT_XBLOCKS | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1789                 },
1790                 &wal_segment_size,
1791                 (XLOG_SEG_SIZE / XLOG_BLCKSZ),
1792                 (XLOG_SEG_SIZE / XLOG_BLCKSZ),
1793                 (XLOG_SEG_SIZE / XLOG_BLCKSZ),
1794                 NULL, NULL
1795         },
1796
1797         {
1798                 {"autovacuum_naptime", PGC_SIGHUP, AUTOVACUUM,
1799                         gettext_noop("Time to sleep between autovacuum runs."),
1800                         NULL,
1801                         GUC_UNIT_S
1802                 },
1803                 &autovacuum_naptime,
1804                 60, 1, INT_MAX / 1000, NULL, NULL
1805         },
1806         {
1807                 {"autovacuum_vacuum_threshold", PGC_SIGHUP, AUTOVACUUM,
1808                         gettext_noop("Minimum number of tuple updates or deletes prior to vacuum."),
1809                         NULL
1810                 },
1811                 &autovacuum_vac_thresh,
1812                 50, 0, INT_MAX, NULL, NULL
1813         },
1814         {
1815                 {"autovacuum_analyze_threshold", PGC_SIGHUP, AUTOVACUUM,
1816                         gettext_noop("Minimum number of tuple inserts, updates or deletes prior to analyze."),
1817                         NULL
1818                 },
1819                 &autovacuum_anl_thresh,
1820                 50, 0, INT_MAX, NULL, NULL
1821         },
1822         {
1823                 /* see varsup.c for why this is PGC_POSTMASTER not PGC_SIGHUP */
1824                 {"autovacuum_freeze_max_age", PGC_POSTMASTER, AUTOVACUUM,
1825                         gettext_noop("Age at which to autovacuum a table to prevent transaction ID wraparound."),
1826                         NULL
1827                 },
1828                 &autovacuum_freeze_max_age,
1829                 200000000, 100000000, 2000000000, NULL, NULL
1830         },
1831         {
1832                 /* see max_connections */
1833                 {"autovacuum_max_workers", PGC_POSTMASTER, AUTOVACUUM,
1834                         gettext_noop("Sets the maximum number of simultaneously running autovacuum worker processes."),
1835                         NULL
1836                 },
1837                 &autovacuum_max_workers,
1838                 3, 1, INT_MAX / 4, assign_autovacuum_max_workers, NULL
1839         },
1840
1841         {
1842                 {"tcp_keepalives_idle", PGC_USERSET, CLIENT_CONN_OTHER,
1843                         gettext_noop("Time between issuing TCP keepalives."),
1844                         gettext_noop("A value of 0 uses the system default."),
1845                         GUC_UNIT_S
1846                 },
1847                 &tcp_keepalives_idle,
1848                 0, 0, INT_MAX, assign_tcp_keepalives_idle, show_tcp_keepalives_idle
1849         },
1850
1851         {
1852                 {"tcp_keepalives_interval", PGC_USERSET, CLIENT_CONN_OTHER,
1853                         gettext_noop("Time between TCP keepalive retransmits."),
1854                         gettext_noop("A value of 0 uses the system default."),
1855                         GUC_UNIT_S
1856                 },
1857                 &tcp_keepalives_interval,
1858                 0, 0, INT_MAX, assign_tcp_keepalives_interval, show_tcp_keepalives_interval
1859         },
1860
1861         {
1862                 {"tcp_keepalives_count", PGC_USERSET, CLIENT_CONN_OTHER,
1863                         gettext_noop("Maximum number of TCP keepalive retransmits."),
1864                         gettext_noop("This controls the number of consecutive keepalive retransmits that can be "
1865                                                  "lost before a connection is considered dead. A value of 0 uses the "
1866                                                  "system default."),
1867                 },
1868                 &tcp_keepalives_count,
1869                 0, 0, INT_MAX, assign_tcp_keepalives_count, show_tcp_keepalives_count
1870         },
1871
1872         {
1873                 {"gin_fuzzy_search_limit", PGC_USERSET, CLIENT_CONN_OTHER,
1874                         gettext_noop("Sets the maximum allowed result for exact search by GIN."),
1875                         NULL,
1876                         0
1877                 },
1878                 &GinFuzzySearchLimit,
1879                 0, 0, INT_MAX, NULL, NULL
1880         },
1881
1882         {
1883                 {"effective_cache_size", PGC_USERSET, QUERY_TUNING_COST,
1884                         gettext_noop("Sets the planner's assumption about the size of the disk cache."),
1885                         gettext_noop("That is, the portion of the kernel's disk cache that "
1886                                                  "will be used for PostgreSQL data files. This is measured in disk "
1887                                                  "pages, which are normally 8 kB each."),
1888                         GUC_UNIT_BLOCKS,
1889                 },
1890                 &effective_cache_size,
1891                 DEFAULT_EFFECTIVE_CACHE_SIZE, 1, INT_MAX, NULL, NULL
1892         },
1893
1894         {
1895                 /* Can't be set in postgresql.conf */
1896                 {"server_version_num", PGC_INTERNAL, PRESET_OPTIONS,
1897                         gettext_noop("Shows the server version as an integer."),
1898                         NULL,
1899                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1900                 },
1901                 &server_version_num,
1902                 PG_VERSION_NUM, PG_VERSION_NUM, PG_VERSION_NUM, NULL, NULL
1903         },
1904
1905         {
1906                 {"log_temp_files", PGC_SUSET, LOGGING_WHAT,
1907                         gettext_noop("Log the use of temporary files larger than this number of kilobytes."),
1908                         gettext_noop("Zero logs all files. The default is -1 (turning this feature off)."),
1909                         GUC_UNIT_KB
1910                 },
1911                 &log_temp_files,
1912                 -1, -1, INT_MAX, NULL, NULL
1913         },
1914
1915         {
1916                 {"track_activity_query_size", PGC_POSTMASTER, RESOURCES_MEM,
1917                         gettext_noop("Sets the size reserved for pg_stat_activity.current_query, in bytes."),
1918                         NULL,
1919                 },
1920                 &pgstat_track_activity_query_size,
1921                 1024, 100, 102400, NULL, NULL
1922         },
1923
1924         /* End-of-list marker */
1925         {
1926                 {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL
1927         }
1928 };
1929
1930
1931 static struct config_real ConfigureNamesReal[] =
1932 {
1933         {
1934                 {"seq_page_cost", PGC_USERSET, QUERY_TUNING_COST,
1935                         gettext_noop("Sets the planner's estimate of the cost of a "
1936                                                  "sequentially fetched disk page."),
1937                         NULL
1938                 },
1939                 &seq_page_cost,
1940                 DEFAULT_SEQ_PAGE_COST, 0, DBL_MAX, NULL, NULL
1941         },
1942         {
1943                 {"random_page_cost", PGC_USERSET, QUERY_TUNING_COST,
1944                         gettext_noop("Sets the planner's estimate of the cost of a "
1945                                                  "nonsequentially fetched disk page."),
1946                         NULL
1947                 },
1948                 &random_page_cost,
1949                 DEFAULT_RANDOM_PAGE_COST, 0, DBL_MAX, NULL, NULL
1950         },
1951         {
1952                 {"cpu_tuple_cost", PGC_USERSET, QUERY_TUNING_COST,
1953                         gettext_noop("Sets the planner's estimate of the cost of "
1954                                                  "processing each tuple (row)."),
1955                         NULL
1956                 },
1957                 &cpu_tuple_cost,
1958                 DEFAULT_CPU_TUPLE_COST, 0, DBL_MAX, NULL, NULL
1959         },
1960         {
1961                 {"cpu_index_tuple_cost", PGC_USERSET, QUERY_TUNING_COST,
1962                         gettext_noop("Sets the planner's estimate of the cost of "
1963                                                  "processing each index entry during an index scan."),
1964                         NULL
1965                 },
1966                 &cpu_index_tuple_cost,
1967                 DEFAULT_CPU_INDEX_TUPLE_COST, 0, DBL_MAX, NULL, NULL
1968         },
1969         {
1970                 {"cpu_operator_cost", PGC_USERSET, QUERY_TUNING_COST,
1971                         gettext_noop("Sets the planner's estimate of the cost of "
1972                                                  "processing each operator or function call."),
1973                         NULL
1974                 },
1975                 &cpu_operator_cost,
1976                 DEFAULT_CPU_OPERATOR_COST, 0, DBL_MAX, NULL, NULL
1977         },
1978
1979         {
1980                 {"cursor_tuple_fraction", PGC_USERSET, QUERY_TUNING_OTHER,
1981                         gettext_noop("Sets the planner's estimate of the fraction of "
1982                                                  "a cursor's rows that will be retrieved."),
1983                         NULL
1984                 },
1985                 &cursor_tuple_fraction,
1986                 DEFAULT_CURSOR_TUPLE_FRACTION, 0.0, 1.0, NULL, NULL
1987         },
1988
1989         {
1990                 {"geqo_selection_bias", PGC_USERSET, QUERY_TUNING_GEQO,
1991                         gettext_noop("GEQO: selective pressure within the population."),
1992                         NULL
1993                 },
1994                 &Geqo_selection_bias,
1995                 DEFAULT_GEQO_SELECTION_BIAS, MIN_GEQO_SELECTION_BIAS,
1996                 MAX_GEQO_SELECTION_BIAS, NULL, NULL
1997         },
1998
1999         {
2000                 {"bgwriter_lru_multiplier", PGC_SIGHUP, RESOURCES,
2001                         gettext_noop("Multiple of the average buffer usage to free per round."),
2002                         NULL
2003                 },
2004                 &bgwriter_lru_multiplier,
2005                 2.0, 0.0, 10.0, NULL, NULL
2006         },
2007
2008         {
2009                 {"seed", PGC_USERSET, UNGROUPED,
2010                         gettext_noop("Sets the seed for random-number generation."),
2011                         NULL,
2012                         GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2013                 },
2014                 &phony_random_seed,
2015                 0.0, -1.0, 1.0, assign_random_seed, show_random_seed
2016         },
2017
2018         {
2019                 {"autovacuum_vacuum_scale_factor", PGC_SIGHUP, AUTOVACUUM,
2020                         gettext_noop("Number of tuple updates or deletes prior to vacuum as a fraction of reltuples."),
2021                         NULL
2022                 },
2023                 &autovacuum_vac_scale,
2024                 0.2, 0.0, 100.0, NULL, NULL
2025         },
2026         {
2027                 {"autovacuum_analyze_scale_factor", PGC_SIGHUP, AUTOVACUUM,
2028                         gettext_noop("Number of tuple inserts, updates or deletes prior to analyze as a fraction of reltuples."),
2029                         NULL
2030                 },
2031                 &autovacuum_anl_scale,
2032                 0.1, 0.0, 100.0, NULL, NULL
2033         },
2034
2035         {
2036                 {"checkpoint_completion_target", PGC_SIGHUP, WAL_CHECKPOINTS,
2037                         gettext_noop("Time spent flushing dirty buffers during checkpoint, as fraction of checkpoint interval."),
2038                         NULL
2039                 },
2040                 &CheckPointCompletionTarget,
2041                 0.5, 0.0, 1.0, NULL, NULL
2042         },
2043
2044         /* End-of-list marker */
2045         {
2046                 {NULL, 0, 0, NULL, NULL}, NULL, 0.0, 0.0, 0.0, NULL, NULL
2047         }
2048 };
2049
2050
2051 static struct config_string ConfigureNamesString[] =
2052 {
2053         {
2054                 {"archive_command", PGC_SIGHUP, WAL_SETTINGS,
2055                         gettext_noop("Sets the shell command that will be called to archive a WAL file."),
2056                         NULL
2057                 },
2058                 &XLogArchiveCommand,
2059                 "", NULL, show_archive_command
2060         },
2061
2062         {
2063                 {"client_encoding", PGC_USERSET, CLIENT_CONN_LOCALE,
2064                         gettext_noop("Sets the client's character set encoding."),
2065                         NULL,
2066                         GUC_IS_NAME | GUC_REPORT
2067                 },
2068                 &client_encoding_string,
2069                 "SQL_ASCII", assign_client_encoding, NULL
2070         },
2071
2072         {
2073                 {"log_line_prefix", PGC_SIGHUP, LOGGING_WHAT,
2074                         gettext_noop("Controls information prefixed to each log line."),
2075                         gettext_noop("If blank, no prefix is used.")
2076                 },
2077                 &Log_line_prefix,
2078                 "", NULL, NULL
2079         },
2080
2081         {
2082                 {"log_timezone", PGC_SIGHUP, LOGGING_WHAT,
2083                         gettext_noop("Sets the time zone to use in log messages."),
2084                         NULL
2085                 },
2086                 &log_timezone_string,
2087                 "UNKNOWN", assign_log_timezone, show_log_timezone
2088         },
2089
2090         {
2091                 {"DateStyle", PGC_USERSET, CLIENT_CONN_LOCALE,
2092                         gettext_noop("Sets the display format for date and time values."),
2093                         gettext_noop("Also controls interpretation of ambiguous "
2094                                                  "date inputs."),
2095                         GUC_LIST_INPUT | GUC_REPORT
2096                 },
2097                 &datestyle_string,
2098                 "ISO, MDY", assign_datestyle, NULL
2099         },
2100
2101         {
2102                 {"default_tablespace", PGC_USERSET, CLIENT_CONN_STATEMENT,
2103                         gettext_noop("Sets the default tablespace to create tables and indexes in."),
2104                         gettext_noop("An empty string selects the database's default tablespace."),
2105                         GUC_IS_NAME
2106                 },
2107                 &default_tablespace,
2108                 "", assign_default_tablespace, NULL
2109         },
2110
2111         {
2112                 {"temp_tablespaces", PGC_USERSET, CLIENT_CONN_STATEMENT,
2113                         gettext_noop("Sets the tablespace(s) to use for temporary tables and sort files."),
2114                         NULL,
2115                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2116                 },
2117                 &temp_tablespaces,
2118                 "", assign_temp_tablespaces, NULL
2119         },
2120
2121         {
2122                 {"dynamic_library_path", PGC_SUSET, CLIENT_CONN_OTHER,
2123                         gettext_noop("Sets the path for dynamically loadable modules."),
2124                         gettext_noop("If a dynamically loadable module needs to be opened and "
2125                                                  "the specified name does not have a directory component (i.e., the "
2126                                                  "name does not contain a slash), the system will search this path for "
2127                                                  "the specified file."),
2128                         GUC_SUPERUSER_ONLY
2129                 },
2130                 &Dynamic_library_path,
2131                 "$libdir", NULL, NULL
2132         },
2133
2134         {
2135                 {"krb_realm", PGC_POSTMASTER, CONN_AUTH_SECURITY,
2136                         gettext_noop("Sets realm to match Kerberos and GSSAPI users against."),
2137                         NULL,
2138                         GUC_SUPERUSER_ONLY
2139                 },
2140                 &pg_krb_realm,
2141                 NULL, NULL, NULL
2142         },
2143
2144         {
2145                 {"krb_server_keyfile", PGC_POSTMASTER, CONN_AUTH_SECURITY,
2146                         gettext_noop("Sets the location of the Kerberos server key file."),
2147                         NULL,
2148                         GUC_SUPERUSER_ONLY
2149                 },
2150                 &pg_krb_server_keyfile,
2151                 PG_KRB_SRVTAB, NULL, NULL
2152         },
2153
2154         {
2155                 {"krb_srvname", PGC_POSTMASTER, CONN_AUTH_SECURITY,
2156                         gettext_noop("Sets the name of the Kerberos service."),
2157                         NULL
2158                 },
2159                 &pg_krb_srvnam,
2160                 PG_KRB_SRVNAM, NULL, NULL
2161         },
2162
2163         {
2164                 {"krb_server_hostname", PGC_POSTMASTER, CONN_AUTH_SECURITY,
2165                         gettext_noop("Sets the hostname of the Kerberos server."),
2166                         NULL
2167                 },
2168                 &pg_krb_server_hostname,
2169                 NULL, NULL, NULL
2170         },
2171
2172         {
2173                 {"bonjour_name", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2174                         gettext_noop("Sets the Bonjour broadcast service name."),
2175                         NULL
2176                 },
2177                 &bonjour_name,
2178                 "", NULL, NULL
2179         },
2180
2181         /* See main.c about why defaults for LC_foo are not all alike */
2182
2183         {
2184                 {"lc_collate", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2185                         gettext_noop("Shows the collation order locale."),
2186                         NULL,
2187                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2188                 },
2189                 &locale_collate,
2190                 "C", NULL, NULL
2191         },
2192
2193         {
2194                 {"lc_ctype", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2195                         gettext_noop("Shows the character classification and case conversion locale."),
2196                         NULL,
2197                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2198                 },
2199                 &locale_ctype,
2200                 "C", NULL, NULL
2201         },
2202
2203         {
2204                 {"lc_messages", PGC_SUSET, CLIENT_CONN_LOCALE,
2205                         gettext_noop("Sets the language in which messages are displayed."),
2206                         NULL
2207                 },
2208                 &locale_messages,
2209                 "", locale_messages_assign, NULL
2210         },
2211
2212         {
2213                 {"lc_monetary", PGC_USERSET, CLIENT_CONN_LOCALE,
2214                         gettext_noop("Sets the locale for formatting monetary amounts."),
2215                         NULL
2216                 },
2217                 &locale_monetary,
2218                 "C", locale_monetary_assign, NULL
2219         },
2220
2221         {
2222                 {"lc_numeric", PGC_USERSET, CLIENT_CONN_LOCALE,
2223                         gettext_noop("Sets the locale for formatting numbers."),
2224                         NULL
2225                 },
2226                 &locale_numeric,
2227                 "C", locale_numeric_assign, NULL
2228         },
2229
2230         {
2231                 {"lc_time", PGC_USERSET, CLIENT_CONN_LOCALE,
2232                         gettext_noop("Sets the locale for formatting date and time values."),
2233                         NULL
2234                 },
2235                 &locale_time,
2236                 "C", locale_time_assign, NULL
2237         },
2238
2239         {
2240                 {"shared_preload_libraries", PGC_POSTMASTER, RESOURCES_KERNEL,
2241                         gettext_noop("Lists shared libraries to preload into server."),
2242                         NULL,
2243                         GUC_LIST_INPUT | GUC_LIST_QUOTE | GUC_SUPERUSER_ONLY
2244                 },
2245                 &shared_preload_libraries_string,
2246                 "", NULL, NULL
2247         },
2248
2249         {
2250                 {"local_preload_libraries", PGC_BACKEND, CLIENT_CONN_OTHER,
2251                         gettext_noop("Lists shared libraries to preload into each backend."),
2252                         NULL,
2253                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2254                 },
2255                 &local_preload_libraries_string,
2256                 "", NULL, NULL
2257         },
2258
2259         {
2260                 {"search_path", PGC_USERSET, CLIENT_CONN_STATEMENT,
2261                         gettext_noop("Sets the schema search order for names that are not schema-qualified."),
2262                         NULL,
2263                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2264                 },
2265                 &namespace_search_path,
2266                 "\"$user\",public", assign_search_path, NULL
2267         },
2268
2269         {
2270                 /* Can't be set in postgresql.conf */
2271                 {"server_encoding", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2272                         gettext_noop("Sets the server (database) character set encoding."),
2273                         NULL,
2274                         GUC_IS_NAME | GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2275                 },
2276                 &server_encoding_string,
2277                 "SQL_ASCII", NULL, NULL
2278         },
2279
2280         {
2281                 /* Can't be set in postgresql.conf */
2282                 {"server_version", PGC_INTERNAL, PRESET_OPTIONS,
2283                         gettext_noop("Shows the server version."),
2284                         NULL,
2285                         GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2286                 },
2287                 &server_version_string,
2288                 PG_VERSION, NULL, NULL
2289         },
2290
2291         {
2292                 /* Not for general use --- used by SET ROLE */
2293                 {"role", PGC_USERSET, UNGROUPED,
2294                         gettext_noop("Sets the current role."),
2295                         NULL,
2296                         GUC_IS_NAME | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2297                 },
2298                 &role_string,
2299                 "none", assign_role, show_role
2300         },
2301
2302         {
2303                 /* Not for general use --- used by SET SESSION AUTHORIZATION */
2304                 {"session_authorization", PGC_USERSET, UNGROUPED,
2305                         gettext_noop("Sets the session user name."),
2306                         NULL,
2307                         GUC_IS_NAME | GUC_REPORT | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2308                 },
2309                 &session_authorization_string,
2310                 NULL, assign_session_authorization, show_session_authorization
2311         },
2312
2313         {
2314                 {"log_destination", PGC_SIGHUP, LOGGING_WHERE,
2315                         gettext_noop("Sets the destination for server log output."),
2316                         gettext_noop("Valid values are combinations of \"stderr\", "
2317                                                  "\"syslog\", \"csvlog\", and \"eventlog\", "
2318                                                  "depending on the platform."),
2319                         GUC_LIST_INPUT
2320                 },
2321                 &log_destination_string,
2322                 "stderr", assign_log_destination, NULL
2323         },
2324         {
2325                 {"log_directory", PGC_SIGHUP, LOGGING_WHERE,
2326                         gettext_noop("Sets the destination directory for log files."),
2327                         gettext_noop("Can be specified as relative to the data directory "
2328                                                  "or as absolute path."),
2329                         GUC_SUPERUSER_ONLY
2330                 },
2331                 &Log_directory,
2332                 "pg_log", assign_canonical_path, NULL
2333         },
2334         {
2335                 {"log_filename", PGC_SIGHUP, LOGGING_WHERE,
2336                         gettext_noop("Sets the file name pattern for log files."),
2337                         NULL,
2338                         GUC_SUPERUSER_ONLY
2339                 },
2340                 &Log_filename,
2341                 "postgresql-%Y-%m-%d_%H%M%S.log", NULL, NULL
2342         },
2343
2344 #ifdef HAVE_SYSLOG
2345         {
2346                 {"syslog_ident", PGC_SIGHUP, LOGGING_WHERE,
2347                         gettext_noop("Sets the program name used to identify PostgreSQL "
2348                                                  "messages in syslog."),
2349                         NULL
2350                 },
2351                 &syslog_ident_str,
2352                 "postgres", assign_syslog_ident, NULL
2353         },
2354 #endif
2355
2356         {
2357                 {"TimeZone", PGC_USERSET, CLIENT_CONN_LOCALE,
2358                         gettext_noop("Sets the time zone for displaying and interpreting time stamps."),
2359                         NULL,
2360                         GUC_REPORT
2361                 },
2362                 &timezone_string,
2363                 "UNKNOWN", assign_timezone, show_timezone
2364         },
2365         {
2366                 {"timezone_abbreviations", PGC_USERSET, CLIENT_CONN_LOCALE,
2367                         gettext_noop("Selects a file of time zone abbreviations."),
2368                         NULL
2369                 },
2370                 &timezone_abbreviations_string,
2371                 "UNKNOWN", assign_timezone_abbreviations, NULL
2372         },
2373
2374         {
2375                 {"transaction_isolation", PGC_USERSET, CLIENT_CONN_STATEMENT,
2376                         gettext_noop("Sets the current transaction's isolation level."),
2377                         NULL,
2378                         GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2379                 },
2380                 &XactIsoLevel_string,
2381                 NULL, assign_XactIsoLevel, show_XactIsoLevel
2382         },
2383
2384         {
2385                 {"unix_socket_group", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2386                         gettext_noop("Sets the owning group of the Unix-domain socket."),
2387                         gettext_noop("The owning user of the socket is always the user "
2388                                                  "that starts the server.")
2389                 },
2390                 &Unix_socket_group,
2391                 "", NULL, NULL
2392         },
2393
2394         {
2395                 {"unix_socket_directory", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2396                         gettext_noop("Sets the directory where the Unix-domain socket will be created."),
2397                         NULL,
2398                         GUC_SUPERUSER_ONLY
2399                 },
2400                 &UnixSocketDir,
2401                 "", assign_canonical_path, NULL
2402         },
2403
2404         {
2405                 {"listen_addresses", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2406                         gettext_noop("Sets the host name or IP address(es) to listen to."),
2407                         NULL,
2408                         GUC_LIST_INPUT
2409                 },
2410                 &ListenAddresses,
2411                 "localhost", NULL, NULL
2412         },
2413
2414         {
2415                 {"custom_variable_classes", PGC_SIGHUP, CUSTOM_OPTIONS,
2416                         gettext_noop("Sets the list of known custom variable classes."),
2417                         NULL,
2418                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2419                 },
2420                 &custom_variable_classes,
2421                 NULL, assign_custom_variable_classes, NULL
2422         },
2423
2424         {
2425                 {"data_directory", PGC_POSTMASTER, FILE_LOCATIONS,
2426                         gettext_noop("Sets the server's data directory."),
2427                         NULL,
2428                         GUC_SUPERUSER_ONLY
2429                 },
2430                 &data_directory,
2431                 NULL, NULL, NULL
2432         },
2433
2434         {
2435                 {"config_file", PGC_POSTMASTER, FILE_LOCATIONS,
2436                         gettext_noop("Sets the server's main configuration file."),
2437                         NULL,
2438                         GUC_DISALLOW_IN_FILE | GUC_SUPERUSER_ONLY
2439                 },
2440                 &ConfigFileName,
2441                 NULL, NULL, NULL
2442         },
2443
2444         {
2445                 {"hba_file", PGC_POSTMASTER, FILE_LOCATIONS,
2446                         gettext_noop("Sets the server's \"hba\" configuration file."),
2447                         NULL,
2448                         GUC_SUPERUSER_ONLY
2449                 },
2450                 &HbaFileName,
2451                 NULL, NULL, NULL
2452         },
2453
2454         {
2455                 {"ident_file", PGC_POSTMASTER, FILE_LOCATIONS,
2456                         gettext_noop("Sets the server's \"ident\" configuration file."),
2457                         NULL,
2458                         GUC_SUPERUSER_ONLY
2459                 },
2460                 &IdentFileName,
2461                 NULL, NULL, NULL
2462         },
2463
2464         {
2465                 {"external_pid_file", PGC_POSTMASTER, FILE_LOCATIONS,
2466                         gettext_noop("Writes the postmaster PID to the specified file."),
2467                         NULL,
2468                         GUC_SUPERUSER_ONLY
2469                 },
2470                 &external_pid_file,
2471                 NULL, assign_canonical_path, NULL
2472         },
2473
2474         {
2475                 {"stats_temp_directory", PGC_SIGHUP, STATS_COLLECTOR,
2476                         gettext_noop("Writes temporary statistics files to the specified directory."),
2477                         NULL,
2478                         GUC_SUPERUSER_ONLY
2479                 },
2480                 &pgstat_temp_directory,
2481                 "pg_stat_tmp", assign_pgstat_temp_directory, NULL
2482         },
2483
2484         {
2485                 {"default_text_search_config", PGC_USERSET, CLIENT_CONN_LOCALE,
2486                         gettext_noop("Sets default text search configuration."),
2487                         NULL
2488                 },
2489                 &TSCurrentConfig,
2490                 "pg_catalog.simple", assignTSCurrentConfig, NULL
2491         },
2492
2493 #ifdef USE_SSL
2494         {
2495                 {"ssl_ciphers", PGC_POSTMASTER, CONN_AUTH_SECURITY,
2496                         gettext_noop("Sets the list of allowed SSL ciphers."),
2497                         NULL,
2498                         GUC_SUPERUSER_ONLY
2499                 },
2500                 &SSLCipherSuites,
2501                 "ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH", NULL, NULL
2502         },
2503 #endif   /* USE_SSL */
2504
2505         /* End-of-list marker */
2506         {
2507                 {NULL, 0, 0, NULL, NULL}, NULL, NULL, NULL, NULL
2508         }
2509 };
2510
2511
2512 static struct config_enum ConfigureNamesEnum[] =
2513 {
2514         {
2515                 {"backslash_quote", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
2516                         gettext_noop("Sets whether \"\\'\" is allowed in string literals."),
2517                         NULL
2518                 },
2519                 &backslash_quote,
2520                 BACKSLASH_QUOTE_SAFE_ENCODING, backslash_quote_options, NULL, NULL
2521         },
2522
2523         {
2524                 {"client_min_messages", PGC_USERSET, LOGGING_WHEN,
2525                         gettext_noop("Sets the message levels that are sent to the client."),
2526                         gettext_noop("Each level includes all the levels that follow it. The later"
2527                                                  " the level, the fewer messages are sent.")
2528                 },
2529                 &client_min_messages,
2530                 NOTICE, client_message_level_options, NULL, NULL
2531         },
2532
2533         {
2534                 {"default_transaction_isolation", PGC_USERSET, CLIENT_CONN_STATEMENT,
2535                         gettext_noop("Sets the transaction isolation level of each new transaction."),
2536                         NULL
2537                 },
2538                 &DefaultXactIsoLevel,
2539                 XACT_READ_COMMITTED, isolation_level_options, NULL, NULL
2540         },
2541
2542         {
2543                 {"log_error_verbosity", PGC_SUSET, LOGGING_WHEN,
2544                         gettext_noop("Sets the verbosity of logged messages."),
2545                         NULL
2546                 },
2547                 &Log_error_verbosity,
2548                 PGERROR_DEFAULT, log_error_verbosity_options, NULL, NULL
2549         },
2550
2551         {
2552                 {"log_min_messages", PGC_SUSET, LOGGING_WHEN,
2553                         gettext_noop("Sets the message levels that are logged."),
2554                         gettext_noop("Each level includes all the levels that follow it. The later"
2555                                                  " the level, the fewer messages are sent.")
2556                 },
2557                 &log_min_messages,
2558                 WARNING, server_message_level_options, NULL, NULL
2559         },
2560
2561         {
2562                 {"log_min_error_statement", PGC_SUSET, LOGGING_WHEN,
2563                         gettext_noop("Causes all statements generating error at or above this level to be logged."),
2564                         gettext_noop("Each level includes all the levels that follow it. The later"
2565                                                  " the level, the fewer messages are sent.")
2566                 },
2567                 &log_min_error_statement,
2568                 ERROR, server_message_level_options, NULL, NULL
2569         },
2570
2571         {
2572                 {"log_statement", PGC_SUSET, LOGGING_WHAT,
2573                         gettext_noop("Sets the type of statements logged."),
2574                         NULL
2575                 },
2576                 &log_statement,
2577                 LOGSTMT_NONE, log_statement_options, NULL, NULL
2578         },
2579
2580 #ifdef HAVE_SYSLOG
2581         {
2582                 {"syslog_facility", PGC_SIGHUP, LOGGING_WHERE,
2583                         gettext_noop("Sets the syslog \"facility\" to be used when syslog enabled."),
2584                         NULL
2585                 },
2586                 &syslog_facility,
2587                 LOG_LOCAL0, syslog_facility_options, assign_syslog_facility, NULL
2588         },
2589 #endif
2590
2591         {
2592                 {"regex_flavor", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
2593                         gettext_noop("Sets the regular expression \"flavor\"."),
2594                         NULL
2595                 },
2596                 &regex_flavor,
2597                 REG_ADVANCED, regex_flavor_options, NULL, NULL
2598         },
2599
2600         {
2601                 {"session_replication_role", PGC_SUSET, CLIENT_CONN_STATEMENT,
2602                         gettext_noop("Sets the session's behavior for triggers and rewrite rules."),
2603                         NULL
2604                 },
2605                 &SessionReplicationRole,
2606                 SESSION_REPLICATION_ROLE_ORIGIN, session_replication_role_options,
2607                 assign_session_replication_role, NULL
2608         },
2609
2610         {
2611                 {"track_functions", PGC_SUSET, STATS_COLLECTOR,
2612                         gettext_noop("Collects function-level statistics on database activity."),
2613                         NULL
2614                 },
2615                 &pgstat_track_functions,
2616                 TRACK_FUNC_OFF, track_function_options, NULL, NULL
2617         },
2618
2619         {
2620                 {"wal_sync_method", PGC_SIGHUP, WAL_SETTINGS,
2621                         gettext_noop("Selects the method used for forcing WAL updates to disk."),
2622                         NULL
2623                 },
2624                 &sync_method,
2625                 DEFAULT_SYNC_METHOD, sync_method_options,
2626                 assign_xlog_sync_method, NULL
2627         },
2628
2629         {
2630                 {"xmlbinary", PGC_USERSET, CLIENT_CONN_STATEMENT,
2631                         gettext_noop("Sets how binary values are to be encoded in XML."),
2632                         NULL
2633                 },
2634                 &xmlbinary,
2635                 XMLBINARY_BASE64, xmlbinary_options, NULL, NULL
2636         },
2637
2638         {
2639                 {"xmloption", PGC_USERSET, CLIENT_CONN_STATEMENT,
2640                         gettext_noop("Sets whether XML data in implicit parsing and serialization "
2641                                                  "operations is to be considered as documents or content fragments."),
2642                         NULL
2643                 },
2644                 &xmloption,
2645                 XMLOPTION_CONTENT, xmloption_options, NULL, NULL
2646         },
2647
2648
2649         /* End-of-list marker */
2650         {
2651                 {NULL, 0, 0, NULL, NULL}, NULL, 0, NULL, NULL, NULL
2652         }
2653 };
2654
2655 /******** end of options list ********/
2656
2657
2658 /*
2659  * To allow continued support of obsolete names for GUC variables, we apply
2660  * the following mappings to any unrecognized name.  Note that an old name
2661  * should be mapped to a new one only if the new variable has very similar
2662  * semantics to the old.
2663  */
2664 static const char *const map_old_guc_names[] = {
2665         "sort_mem", "work_mem",
2666         "vacuum_mem", "maintenance_work_mem",
2667         NULL
2668 };
2669
2670
2671 /*
2672  * Actual lookup of variables is done through this single, sorted array.
2673  */
2674 static struct config_generic **guc_variables;
2675
2676 /* Current number of variables contained in the vector */
2677 static int      num_guc_variables;
2678
2679 /* Vector capacity */
2680 static int      size_guc_variables;
2681
2682
2683 static bool guc_dirty;                  /* TRUE if need to do commit/abort work */
2684
2685 static bool reporting_enabled;  /* TRUE to enable GUC_REPORT */
2686
2687 static int      GUCNestLevel = 0;       /* 1 when in main transaction */
2688
2689
2690 static int      guc_var_compare(const void *a, const void *b);
2691 static int      guc_name_compare(const char *namea, const char *nameb);
2692 static void push_old_value(struct config_generic * gconf, GucAction action);
2693 static void ReportGUCOption(struct config_generic * record);
2694 static void ShowGUCConfigOption(const char *name, DestReceiver *dest);
2695 static void ShowAllGUCConfig(DestReceiver *dest);
2696 static char *_ShowOption(struct config_generic * record, bool use_units);
2697 static bool is_newvalue_equal(struct config_generic * record, const char *newvalue);
2698
2699
2700 /*
2701  * Some infrastructure for checking malloc/strdup/realloc calls
2702  */
2703 static void *
2704 guc_malloc(int elevel, size_t size)
2705 {
2706         void       *data;
2707
2708         data = malloc(size);
2709         if (data == NULL)
2710                 ereport(elevel,
2711                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2712                                  errmsg("out of memory")));
2713         return data;
2714 }
2715
2716 static void *
2717 guc_realloc(int elevel, void *old, size_t size)
2718 {
2719         void       *data;
2720
2721         data = realloc(old, size);
2722         if (data == NULL)
2723                 ereport(elevel,
2724                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2725                                  errmsg("out of memory")));
2726         return data;
2727 }
2728
2729 static char *
2730 guc_strdup(int elevel, const char *src)
2731 {
2732         char       *data;
2733
2734         data = strdup(src);
2735         if (data == NULL)
2736                 ereport(elevel,
2737                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2738                                  errmsg("out of memory")));
2739         return data;
2740 }
2741
2742
2743 /*
2744  * Support for assigning to a field of a string GUC item.  Free the prior
2745  * value if it's not referenced anywhere else in the item (including stacked
2746  * states).
2747  */
2748 static void
2749 set_string_field(struct config_string * conf, char **field, char *newval)
2750 {
2751         char       *oldval = *field;
2752         GucStack   *stack;
2753
2754         /* Do the assignment */
2755         *field = newval;
2756
2757         /* Exit if any duplicate references, or if old value was NULL anyway */
2758         if (oldval == NULL ||
2759                 oldval == *(conf->variable) ||
2760                 oldval == conf->reset_val ||
2761                 oldval == conf->boot_val)
2762                 return;
2763         for (stack = conf->gen.stack; stack; stack = stack->prev)
2764         {
2765                 if (oldval == stack->prior.stringval ||
2766                         oldval == stack->masked.stringval)
2767                         return;
2768         }
2769
2770         /* Not used anymore, so free it */
2771         free(oldval);
2772 }
2773
2774 /*
2775  * Detect whether strval is referenced anywhere in a GUC string item
2776  */
2777 static bool
2778 string_field_used(struct config_string * conf, char *strval)
2779 {
2780         GucStack   *stack;
2781
2782         if (strval == *(conf->variable) ||
2783                 strval == conf->reset_val ||
2784                 strval == conf->boot_val)
2785                 return true;
2786         for (stack = conf->gen.stack; stack; stack = stack->prev)
2787         {
2788                 if (strval == stack->prior.stringval ||
2789                         strval == stack->masked.stringval)
2790                         return true;
2791         }
2792         return false;
2793 }
2794
2795 /*
2796  * Support for copying a variable's active value into a stack entry
2797  */
2798 static void
2799 set_stack_value(struct config_generic * gconf, union config_var_value * val)
2800 {
2801         switch (gconf->vartype)
2802         {
2803                 case PGC_BOOL:
2804                         val->boolval =
2805                                 *((struct config_bool *) gconf)->variable;
2806                         break;
2807                 case PGC_INT:
2808                         val->intval =
2809                                 *((struct config_int *) gconf)->variable;
2810                         break;
2811                 case PGC_REAL:
2812                         val->realval =
2813                                 *((struct config_real *) gconf)->variable;
2814                         break;
2815                 case PGC_STRING:
2816                         /* we assume stringval is NULL if not valid */
2817                         set_string_field((struct config_string *) gconf,
2818                                                          &(val->stringval),
2819                                                          *((struct config_string *) gconf)->variable);
2820                         break;
2821                 case PGC_ENUM:
2822                         val->enumval =
2823                                 *((struct config_enum *) gconf)->variable;
2824                         break;
2825         }
2826 }
2827
2828 /*
2829  * Support for discarding a no-longer-needed value in a stack entry
2830  */
2831 static void
2832 discard_stack_value(struct config_generic * gconf, union config_var_value * val)
2833 {
2834         switch (gconf->vartype)
2835         {
2836                 case PGC_BOOL:
2837                 case PGC_INT:
2838                 case PGC_REAL:
2839                 case PGC_ENUM:
2840                         /* no need to do anything */
2841                         break;
2842                 case PGC_STRING:
2843                         set_string_field((struct config_string *) gconf,
2844                                                          &(val->stringval),
2845                                                          NULL);
2846                         break;
2847         }
2848 }
2849
2850
2851 /*
2852  * Fetch the sorted array pointer (exported for help_config.c's use ONLY)
2853  */
2854 struct config_generic **
2855 get_guc_variables(void)
2856 {
2857         return guc_variables;
2858 }
2859
2860
2861 /*
2862  * Build the sorted array.      This is split out so that it could be
2863  * re-executed after startup (eg, we could allow loadable modules to
2864  * add vars, and then we'd need to re-sort).
2865  */
2866 void
2867 build_guc_variables(void)
2868 {
2869         int                     size_vars;
2870         int                     num_vars = 0;
2871         struct config_generic **guc_vars;
2872         int                     i;
2873
2874         for (i = 0; ConfigureNamesBool[i].gen.name; i++)
2875         {
2876                 struct config_bool *conf = &ConfigureNamesBool[i];
2877
2878                 /* Rather than requiring vartype to be filled in by hand, do this: */
2879                 conf->gen.vartype = PGC_BOOL;
2880                 num_vars++;
2881         }
2882
2883         for (i = 0; ConfigureNamesInt[i].gen.name; i++)
2884         {
2885                 struct config_int *conf = &ConfigureNamesInt[i];
2886
2887                 conf->gen.vartype = PGC_INT;
2888                 num_vars++;
2889         }
2890
2891         for (i = 0; ConfigureNamesReal[i].gen.name; i++)
2892         {
2893                 struct config_real *conf = &ConfigureNamesReal[i];
2894
2895                 conf->gen.vartype = PGC_REAL;
2896                 num_vars++;
2897         }
2898
2899         for (i = 0; ConfigureNamesString[i].gen.name; i++)
2900         {
2901                 struct config_string *conf = &ConfigureNamesString[i];
2902
2903                 conf->gen.vartype = PGC_STRING;
2904                 num_vars++;
2905         }
2906
2907         for (i = 0; ConfigureNamesEnum[i].gen.name; i++)
2908         {
2909                 struct config_enum *conf = &ConfigureNamesEnum[i];
2910
2911                 conf->gen.vartype = PGC_ENUM;
2912                 num_vars++;
2913         }
2914
2915         /*
2916          * Create table with 20% slack
2917          */
2918         size_vars = num_vars + num_vars / 4;
2919
2920         guc_vars = (struct config_generic **)
2921                 guc_malloc(FATAL, size_vars * sizeof(struct config_generic *));
2922
2923         num_vars = 0;
2924
2925         for (i = 0; ConfigureNamesBool[i].gen.name; i++)
2926                 guc_vars[num_vars++] = &ConfigureNamesBool[i].gen;
2927
2928         for (i = 0; ConfigureNamesInt[i].gen.name; i++)
2929                 guc_vars[num_vars++] = &ConfigureNamesInt[i].gen;
2930
2931         for (i = 0; ConfigureNamesReal[i].gen.name; i++)
2932                 guc_vars[num_vars++] = &ConfigureNamesReal[i].gen;
2933
2934         for (i = 0; ConfigureNamesString[i].gen.name; i++)
2935                 guc_vars[num_vars++] = &ConfigureNamesString[i].gen;
2936
2937         for (i = 0; ConfigureNamesEnum[i].gen.name; i++)
2938                 guc_vars[num_vars++] = &ConfigureNamesEnum[i].gen;
2939
2940         if (guc_variables)
2941                 free(guc_variables);
2942         guc_variables = guc_vars;
2943         num_guc_variables = num_vars;
2944         size_guc_variables = size_vars;
2945         qsort((void *) guc_variables, num_guc_variables,
2946                   sizeof(struct config_generic *), guc_var_compare);
2947 }
2948
2949 /*
2950  * Add a new GUC variable to the list of known variables. The
2951  * list is expanded if needed.
2952  */
2953 static bool
2954 add_guc_variable(struct config_generic * var, int elevel)
2955 {
2956         if (num_guc_variables + 1 >= size_guc_variables)
2957         {
2958                 /*
2959                  * Increase the vector by 25%
2960                  */
2961                 int                     size_vars = size_guc_variables + size_guc_variables / 4;
2962                 struct config_generic **guc_vars;
2963
2964                 if (size_vars == 0)
2965                 {
2966                         size_vars = 100;
2967                         guc_vars = (struct config_generic **)
2968                                 guc_malloc(elevel, size_vars * sizeof(struct config_generic *));
2969                 }
2970                 else
2971                 {
2972                         guc_vars = (struct config_generic **)
2973                                 guc_realloc(elevel, guc_variables, size_vars * sizeof(struct config_generic *));
2974                 }
2975
2976                 if (guc_vars == NULL)
2977                         return false;           /* out of memory */
2978
2979                 guc_variables = guc_vars;
2980                 size_guc_variables = size_vars;
2981         }
2982         guc_variables[num_guc_variables++] = var;
2983         qsort((void *) guc_variables, num_guc_variables,
2984                   sizeof(struct config_generic *), guc_var_compare);
2985         return true;
2986 }
2987
2988 /*
2989  * Create and add a placeholder variable. It's presumed to belong
2990  * to a valid custom variable class at this point.
2991  */
2992 static struct config_generic *
2993 add_placeholder_variable(const char *name, int elevel)
2994 {
2995         size_t          sz = sizeof(struct config_string) + sizeof(char *);
2996         struct config_string *var;
2997         struct config_generic *gen;
2998
2999         var = (struct config_string *) guc_malloc(elevel, sz);
3000         if (var == NULL)
3001                 return NULL;
3002         memset(var, 0, sz);
3003         gen = &var->gen;
3004
3005         gen->name = guc_strdup(elevel, name);
3006         if (gen->name == NULL)
3007         {
3008                 free(var);
3009                 return NULL;
3010         }
3011
3012         gen->context = PGC_USERSET;
3013         gen->group = CUSTOM_OPTIONS;
3014         gen->short_desc = "GUC placeholder variable";
3015         gen->flags = GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE | GUC_CUSTOM_PLACEHOLDER;
3016         gen->vartype = PGC_STRING;
3017
3018         /*
3019          * The char* is allocated at the end of the struct since we have no
3020          * 'static' place to point to.  Note that the current value, as well as
3021          * the boot and reset values, start out NULL.
3022          */
3023         var->variable = (char **) (var + 1);
3024
3025         if (!add_guc_variable((struct config_generic *) var, elevel))
3026         {
3027                 free((void *) gen->name);
3028                 free(var);
3029                 return NULL;
3030         }
3031
3032         return gen;
3033 }
3034
3035 /*
3036  * Detect whether the portion of "name" before dotPos matches any custom
3037  * variable class name listed in custom_var_classes.  The latter must be
3038  * formatted the way that assign_custom_variable_classes does it, ie,
3039  * no whitespace.  NULL is valid for custom_var_classes.
3040  */
3041 static bool
3042 is_custom_class(const char *name, int dotPos, const char *custom_var_classes)
3043 {
3044         bool            result = false;
3045         const char *ccs = custom_var_classes;
3046
3047         if (ccs != NULL)
3048         {
3049                 const char *start = ccs;
3050
3051                 for (;; ++ccs)
3052                 {
3053                         char            c = *ccs;
3054
3055                         if (c == '\0' || c == ',')
3056                         {
3057                                 if (dotPos == ccs - start && strncmp(start, name, dotPos) == 0)
3058                                 {
3059                                         result = true;
3060                                         break;
3061                                 }
3062                                 if (c == '\0')
3063                                         break;
3064                                 start = ccs + 1;
3065                         }
3066                 }
3067         }
3068         return result;
3069 }
3070
3071 /*
3072  * Look up option NAME.  If it exists, return a pointer to its record,
3073  * else return NULL.  If create_placeholders is TRUE, we'll create a
3074  * placeholder record for a valid-looking custom variable name.
3075  */
3076 static struct config_generic *
3077 find_option(const char *name, bool create_placeholders, int elevel)
3078 {
3079         const char **key = &name;
3080         struct config_generic **res;
3081         int                     i;
3082
3083         Assert(name);
3084
3085         /*
3086          * By equating const char ** with struct config_generic *, we are assuming
3087          * the name field is first in config_generic.
3088          */
3089         res = (struct config_generic **) bsearch((void *) &key,
3090                                                                                          (void *) guc_variables,
3091                                                                                          num_guc_variables,
3092                                                                                          sizeof(struct config_generic *),
3093                                                                                          guc_var_compare);
3094         if (res)
3095                 return *res;
3096
3097         /*
3098          * See if the name is an obsolete name for a variable.  We assume that the
3099          * set of supported old names is short enough that a brute-force search is
3100          * the best way.
3101          */
3102         for (i = 0; map_old_guc_names[i] != NULL; i += 2)
3103         {
3104                 if (guc_name_compare(name, map_old_guc_names[i]) == 0)
3105                         return find_option(map_old_guc_names[i + 1], false, elevel);
3106         }
3107
3108         if (create_placeholders)
3109         {
3110                 /*
3111                  * Check if the name is qualified, and if so, check if the qualifier
3112                  * matches any custom variable class.  If so, add a placeholder.
3113                  */
3114                 const char *dot = strchr(name, GUC_QUALIFIER_SEPARATOR);
3115
3116                 if (dot != NULL &&
3117                         is_custom_class(name, dot - name, custom_variable_classes))
3118                         return add_placeholder_variable(name, elevel);
3119         }
3120
3121         /* Unknown name */
3122         return NULL;
3123 }
3124
3125
3126 /*
3127  * comparator for qsorting and bsearching guc_variables array
3128  */
3129 static int
3130 guc_var_compare(const void *a, const void *b)
3131 {
3132         struct config_generic *confa = *(struct config_generic **) a;
3133         struct config_generic *confb = *(struct config_generic **) b;
3134
3135         return guc_name_compare(confa->name, confb->name);
3136 }
3137
3138 /*
3139  * the bare comparison function for GUC names
3140  */
3141 static int
3142 guc_name_compare(const char *namea, const char *nameb)
3143 {
3144         /*
3145          * The temptation to use strcasecmp() here must be resisted, because the
3146          * array ordering has to remain stable across setlocale() calls. So, build
3147          * our own with a simple ASCII-only downcasing.
3148          */
3149         while (*namea && *nameb)
3150         {
3151                 char            cha = *namea++;
3152                 char            chb = *nameb++;
3153
3154                 if (cha >= 'A' && cha <= 'Z')
3155                         cha += 'a' - 'A';
3156                 if (chb >= 'A' && chb <= 'Z')
3157                         chb += 'a' - 'A';
3158                 if (cha != chb)
3159                         return cha - chb;
3160         }
3161         if (*namea)
3162                 return 1;                               /* a is longer */
3163         if (*nameb)
3164                 return -1;                              /* b is longer */
3165         return 0;
3166 }
3167
3168
3169 /*
3170  * Initialize GUC options during program startup.
3171  *
3172  * Note that we cannot read the config file yet, since we have not yet
3173  * processed command-line switches.
3174  */
3175 void
3176 InitializeGUCOptions(void)
3177 {
3178         int                     i;
3179         char       *env;
3180         long            stack_rlimit;
3181
3182         /*
3183          * Before log_line_prefix could possibly receive a nonempty setting, make
3184          * sure that timezone processing is minimally alive (see elog.c).
3185          */
3186         pg_timezone_pre_initialize();
3187
3188         /*
3189          * Build sorted array of all GUC variables.
3190          */
3191         build_guc_variables();
3192
3193         /*
3194          * Load all variables with their compiled-in defaults, and initialize
3195          * status fields as needed.
3196          */
3197         for (i = 0; i < num_guc_variables; i++)
3198         {
3199                 struct config_generic *gconf = guc_variables[i];
3200
3201                 gconf->status = 0;
3202                 gconf->reset_source = PGC_S_DEFAULT;
3203                 gconf->source = PGC_S_DEFAULT;
3204                 gconf->stack = NULL;
3205                 gconf->sourcefile = NULL;
3206                 gconf->sourceline = 0;
3207
3208                 switch (gconf->vartype)
3209                 {
3210                         case PGC_BOOL:
3211                                 {
3212                                         struct config_bool *conf = (struct config_bool *) gconf;
3213
3214                                         if (conf->assign_hook)
3215                                                 if (!(*conf->assign_hook) (conf->boot_val, true,
3216                                                                                                    PGC_S_DEFAULT))
3217                                                         elog(FATAL, "failed to initialize %s to %d",
3218                                                                  conf->gen.name, (int) conf->boot_val);
3219                                         *conf->variable = conf->reset_val = conf->boot_val;
3220                                         break;
3221                                 }
3222                         case PGC_INT:
3223                                 {
3224                                         struct config_int *conf = (struct config_int *) gconf;
3225
3226                                         Assert(conf->boot_val >= conf->min);
3227                                         Assert(conf->boot_val <= conf->max);
3228                                         if (conf->assign_hook)
3229                                                 if (!(*conf->assign_hook) (conf->boot_val, true,
3230                                                                                                    PGC_S_DEFAULT))
3231                                                         elog(FATAL, "failed to initialize %s to %d",
3232                                                                  conf->gen.name, conf->boot_val);
3233                                         *conf->variable = conf->reset_val = conf->boot_val;
3234                                         break;
3235                                 }
3236                         case PGC_REAL:
3237                                 {
3238                                         struct config_real *conf = (struct config_real *) gconf;
3239
3240                                         Assert(conf->boot_val >= conf->min);
3241                                         Assert(conf->boot_val <= conf->max);
3242                                         if (conf->assign_hook)
3243                                                 if (!(*conf->assign_hook) (conf->boot_val, true,
3244                                                                                                    PGC_S_DEFAULT))
3245                                                         elog(FATAL, "failed to initialize %s to %g",
3246                                                                  conf->gen.name, conf->boot_val);
3247                                         *conf->variable = conf->reset_val = conf->boot_val;
3248                                         break;
3249                                 }
3250                         case PGC_STRING:
3251                                 {
3252                                         struct config_string *conf = (struct config_string *) gconf;
3253                                         char       *str;
3254
3255                                         *conf->variable = NULL;
3256                                         conf->reset_val = NULL;
3257
3258                                         if (conf->boot_val == NULL)
3259                                         {
3260                                                 /* leave the value NULL, do not call assign hook */
3261                                                 break;
3262                                         }
3263
3264                                         str = guc_strdup(FATAL, conf->boot_val);
3265                                         conf->reset_val = str;
3266
3267                                         if (conf->assign_hook)
3268                                         {
3269                                                 const char *newstr;
3270
3271                                                 newstr = (*conf->assign_hook) (str, true,
3272                                                                                                            PGC_S_DEFAULT);
3273                                                 if (newstr == NULL)
3274                                                 {
3275                                                         elog(FATAL, "failed to initialize %s to \"%s\"",
3276                                                                  conf->gen.name, str);
3277                                                 }
3278                                                 else if (newstr != str)
3279                                                 {
3280                                                         free(str);
3281
3282                                                         /*
3283                                                          * See notes in set_config_option about casting
3284                                                          */
3285                                                         str = (char *) newstr;
3286                                                         conf->reset_val = str;
3287                                                 }
3288                                         }
3289                                         *conf->variable = str;
3290                                         break;
3291                                 }
3292                         case PGC_ENUM:
3293                                 {
3294                                         struct config_enum *conf = (struct config_enum *) gconf;
3295
3296                                         if (conf->assign_hook)
3297                                                 if (!(*conf->assign_hook) (conf->boot_val, true,
3298                                                                                                    PGC_S_DEFAULT))
3299                                                         elog(FATAL, "failed to initialize %s to %s",
3300                                                                  conf->gen.name,
3301                                                                  config_enum_lookup_by_value(conf, conf->boot_val));
3302                                         *conf->variable = conf->reset_val = conf->boot_val;
3303                                         break;
3304                                 }
3305                 }
3306         }
3307
3308         guc_dirty = false;
3309
3310         reporting_enabled = false;
3311
3312         /*
3313          * Prevent any attempt to override the transaction modes from
3314          * non-interactive sources.
3315          */
3316         SetConfigOption("transaction_isolation", "default",
3317                                         PGC_POSTMASTER, PGC_S_OVERRIDE);
3318         SetConfigOption("transaction_read_only", "no",
3319                                         PGC_POSTMASTER, PGC_S_OVERRIDE);
3320
3321         /*
3322          * For historical reasons, some GUC parameters can receive defaults from
3323          * environment variables.  Process those settings.      NB: if you add or
3324          * remove anything here, see also ProcessConfigFile().
3325          */
3326
3327         env = getenv("PGPORT");
3328         if (env != NULL)
3329                 SetConfigOption("port", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3330
3331         env = getenv("PGDATESTYLE");
3332         if (env != NULL)
3333                 SetConfigOption("datestyle", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3334
3335         env = getenv("PGCLIENTENCODING");
3336         if (env != NULL)
3337                 SetConfigOption("client_encoding", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3338
3339         /*
3340          * rlimit isn't exactly an "environment variable", but it behaves about
3341          * the same.  If we can identify the platform stack depth rlimit, increase
3342          * default stack depth setting up to whatever is safe (but at most 2MB).
3343          */
3344         stack_rlimit = get_stack_depth_rlimit();
3345         if (stack_rlimit > 0)
3346         {
3347                 int                     new_limit = (stack_rlimit - STACK_DEPTH_SLOP) / 1024L;
3348
3349                 if (new_limit > 100)
3350                 {
3351                         char            limbuf[16];
3352
3353                         new_limit = Min(new_limit, 2048);
3354                         sprintf(limbuf, "%d", new_limit);
3355                         SetConfigOption("max_stack_depth", limbuf,
3356                                                         PGC_POSTMASTER, PGC_S_ENV_VAR);
3357                 }
3358         }
3359 }
3360
3361
3362 /*
3363  * Select the configuration files and data directory to be used, and
3364  * do the initial read of postgresql.conf.
3365  *
3366  * This is called after processing command-line switches.
3367  *              userDoption is the -D switch value if any (NULL if unspecified).
3368  *              progname is just for use in error messages.
3369  *
3370  * Returns true on success; on failure, prints a suitable error message
3371  * to stderr and returns false.
3372  */
3373 bool
3374 SelectConfigFiles(const char *userDoption, const char *progname)
3375 {
3376         char       *configdir;
3377         char       *fname;
3378         struct stat stat_buf;
3379
3380         /* configdir is -D option, or $PGDATA if no -D */
3381         if (userDoption)
3382                 configdir = make_absolute_path(userDoption);
3383         else
3384                 configdir = make_absolute_path(getenv("PGDATA"));
3385
3386         /*
3387          * Find the configuration file: if config_file was specified on the
3388          * command line, use it, else use configdir/postgresql.conf.  In any case
3389          * ensure the result is an absolute path, so that it will be interpreted
3390          * the same way by future backends.
3391          */
3392         if (ConfigFileName)
3393                 fname = make_absolute_path(ConfigFileName);
3394         else if (configdir)
3395         {
3396                 fname = guc_malloc(FATAL,
3397                                                    strlen(configdir) + strlen(CONFIG_FILENAME) + 2);
3398                 sprintf(fname, "%s/%s", configdir, CONFIG_FILENAME);
3399         }
3400         else
3401         {
3402                 write_stderr("%s does not know where to find the server configuration file.\n"
3403                                          "You must specify the --config-file or -D invocation "
3404                                          "option or set the PGDATA environment variable.\n",
3405                                          progname);
3406                 return false;
3407         }
3408
3409         /*
3410          * Set the ConfigFileName GUC variable to its final value, ensuring that
3411          * it can't be overridden later.
3412          */
3413         SetConfigOption("config_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3414         free(fname);
3415
3416         /*
3417          * Now read the config file for the first time.
3418          */
3419         if (stat(ConfigFileName, &stat_buf) != 0)
3420         {
3421                 write_stderr("%s cannot access the server configuration file \"%s\": %s\n",
3422                                          progname, ConfigFileName, strerror(errno));
3423                 return false;
3424         }
3425
3426         ProcessConfigFile(PGC_POSTMASTER);
3427
3428         /*
3429          * If the data_directory GUC variable has been set, use that as DataDir;
3430          * otherwise use configdir if set; else punt.
3431          *
3432          * Note: SetDataDir will copy and absolute-ize its argument, so we don't
3433          * have to.
3434          */
3435         if (data_directory)
3436                 SetDataDir(data_directory);
3437         else if (configdir)
3438                 SetDataDir(configdir);
3439         else
3440         {
3441                 write_stderr("%s does not know where to find the database system data.\n"
3442                                          "This can be specified as \"data_directory\" in \"%s\", "
3443                                          "or by the -D invocation option, or by the "
3444                                          "PGDATA environment variable.\n",
3445                                          progname, ConfigFileName);
3446                 return false;
3447         }
3448
3449         /*
3450          * Reflect the final DataDir value back into the data_directory GUC var.
3451          * (If you are wondering why we don't just make them a single variable,
3452          * it's because the EXEC_BACKEND case needs DataDir to be transmitted to
3453          * child backends specially.  XXX is that still true?  Given that we now
3454          * chdir to DataDir, EXEC_BACKEND can read the config file without knowing
3455          * DataDir in advance.)
3456          */
3457         SetConfigOption("data_directory", DataDir, PGC_POSTMASTER, PGC_S_OVERRIDE);
3458
3459         /*
3460          * Figure out where pg_hba.conf is, and make sure the path is absolute.
3461          */
3462         if (HbaFileName)
3463                 fname = make_absolute_path(HbaFileName);
3464         else if (configdir)
3465         {
3466                 fname = guc_malloc(FATAL,
3467                                                    strlen(configdir) + strlen(HBA_FILENAME) + 2);
3468                 sprintf(fname, "%s/%s", configdir, HBA_FILENAME);
3469         }
3470         else
3471         {
3472                 write_stderr("%s does not know where to find the \"hba\" configuration file.\n"
3473                                          "This can be specified as \"hba_file\" in \"%s\", "
3474                                          "or by the -D invocation option, or by the "
3475                                          "PGDATA environment variable.\n",
3476                                          progname, ConfigFileName);
3477                 return false;
3478         }
3479         SetConfigOption("hba_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3480         free(fname);
3481
3482         /*
3483          * Likewise for pg_ident.conf.
3484          */
3485         if (IdentFileName)
3486                 fname = make_absolute_path(IdentFileName);
3487         else if (configdir)
3488         {
3489                 fname = guc_malloc(FATAL,
3490                                                    strlen(configdir) + strlen(IDENT_FILENAME) + 2);
3491                 sprintf(fname, "%s/%s", configdir, IDENT_FILENAME);
3492         }
3493         else
3494         {
3495                 write_stderr("%s does not know where to find the \"ident\" configuration file.\n"
3496                                          "This can be specified as \"ident_file\" in \"%s\", "
3497                                          "or by the -D invocation option, or by the "
3498                                          "PGDATA environment variable.\n",
3499                                          progname, ConfigFileName);
3500                 return false;
3501         }
3502         SetConfigOption("ident_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3503         free(fname);
3504
3505         free(configdir);
3506
3507         return true;
3508 }
3509
3510
3511 /*
3512  * Reset all options to their saved default values (implements RESET ALL)
3513  */
3514 void
3515 ResetAllOptions(void)
3516 {
3517         int                     i;
3518
3519         for (i = 0; i < num_guc_variables; i++)
3520         {
3521                 struct config_generic *gconf = guc_variables[i];
3522
3523                 /* Don't reset non-SET-able values */
3524                 if (gconf->context != PGC_SUSET &&
3525                         gconf->context != PGC_USERSET)
3526                         continue;
3527                 /* Don't reset if special exclusion from RESET ALL */
3528                 if (gconf->flags & GUC_NO_RESET_ALL)
3529                         continue;
3530                 /* No need to reset if wasn't SET */
3531                 if (gconf->source <= PGC_S_OVERRIDE)
3532                         continue;
3533
3534                 /* Save old value to support transaction abort */
3535                 push_old_value(gconf, GUC_ACTION_SET);
3536
3537                 switch (gconf->vartype)
3538                 {
3539                         case PGC_BOOL:
3540                                 {
3541                                         struct config_bool *conf = (struct config_bool *) gconf;
3542
3543                                         if (conf->assign_hook)
3544                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3545                                                                                                    PGC_S_SESSION))
3546                                                         elog(ERROR, "failed to reset %s", conf->gen.name);
3547                                         *conf->variable = conf->reset_val;
3548                                         break;
3549                                 }
3550                         case PGC_INT:
3551                                 {
3552                                         struct config_int *conf = (struct config_int *) gconf;
3553
3554                                         if (conf->assign_hook)
3555                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3556                                                                                                    PGC_S_SESSION))
3557                                                         elog(ERROR, "failed to reset %s", conf->gen.name);
3558                                         *conf->variable = conf->reset_val;
3559                                         break;
3560                                 }
3561                         case PGC_REAL:
3562                                 {
3563                                         struct config_real *conf = (struct config_real *) gconf;
3564
3565                                         if (conf->assign_hook)
3566                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3567                                                                                                    PGC_S_SESSION))
3568                                                         elog(ERROR, "failed to reset %s", conf->gen.name);
3569                                         *conf->variable = conf->reset_val;
3570                                         break;
3571                                 }
3572                         case PGC_STRING:
3573                                 {
3574                                         struct config_string *conf = (struct config_string *) gconf;
3575                                         char       *str;
3576
3577                                         /* We need not strdup here */
3578                                         str = conf->reset_val;
3579
3580                                         if (conf->assign_hook && str)
3581                                         {
3582                                                 const char *newstr;
3583
3584                                                 newstr = (*conf->assign_hook) (str, true,
3585                                                                                                            PGC_S_SESSION);
3586                                                 if (newstr == NULL)
3587                                                         elog(ERROR, "failed to reset %s", conf->gen.name);
3588                                                 else if (newstr != str)
3589                                                 {
3590                                                         /*
3591                                                          * See notes in set_config_option about casting
3592                                                          */
3593                                                         str = (char *) newstr;
3594                                                 }
3595                                         }
3596
3597                                         set_string_field(conf, conf->variable, str);
3598                                         break;
3599                                 }
3600                         case PGC_ENUM:
3601                                 {
3602                                         struct config_enum *conf = (struct config_enum *) gconf;
3603
3604                                         if (conf->assign_hook)
3605                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3606                                                                                                    PGC_S_SESSION))
3607                                                         elog(ERROR, "failed to reset %s", conf->gen.name);
3608                                         *conf->variable = conf->reset_val;
3609                                         break;
3610                                 }
3611                 }
3612
3613                 gconf->source = gconf->reset_source;
3614
3615                 if (gconf->flags & GUC_REPORT)
3616                         ReportGUCOption(gconf);
3617         }
3618 }
3619
3620
3621 /*
3622  * push_old_value
3623  *              Push previous state during transactional assignment to a GUC variable.
3624  */
3625 static void
3626 push_old_value(struct config_generic * gconf, GucAction action)
3627 {
3628         GucStack   *stack;
3629
3630         /* If we're not inside a nest level, do nothing */
3631         if (GUCNestLevel == 0)
3632                 return;
3633
3634         /* Do we already have a stack entry of the current nest level? */
3635         stack = gconf->stack;
3636         if (stack && stack->nest_level >= GUCNestLevel)
3637         {
3638                 /* Yes, so adjust its state if necessary */
3639                 Assert(stack->nest_level == GUCNestLevel);
3640                 switch (action)
3641                 {
3642                         case GUC_ACTION_SET:
3643                                 /* SET overrides any prior action at same nest level */
3644                                 if (stack->state == GUC_SET_LOCAL)
3645                                 {
3646                                         /* must discard old masked value */
3647                                         discard_stack_value(gconf, &stack->masked);
3648                                 }
3649                                 stack->state = GUC_SET;
3650                                 break;
3651                         case GUC_ACTION_LOCAL:
3652                                 if (stack->state == GUC_SET)
3653                                 {
3654                                         /* SET followed by SET LOCAL, remember SET's value */
3655                                         set_stack_value(gconf, &stack->masked);
3656                                         stack->state = GUC_SET_LOCAL;
3657                                 }
3658                                 /* in all other cases, no change to stack entry */
3659                                 break;
3660                         case GUC_ACTION_SAVE:
3661                                 /* Could only have a prior SAVE of same variable */
3662                                 Assert(stack->state == GUC_SAVE);
3663                                 break;
3664                 }
3665                 Assert(guc_dirty);              /* must be set already */
3666                 return;
3667         }
3668
3669         /*
3670          * Push a new stack entry
3671          *
3672          * We keep all the stack entries in TopTransactionContext for simplicity.
3673          */
3674         stack = (GucStack *) MemoryContextAllocZero(TopTransactionContext,
3675                                                                                                 sizeof(GucStack));
3676
3677         stack->prev = gconf->stack;
3678         stack->nest_level = GUCNestLevel;
3679         switch (action)
3680         {
3681                 case GUC_ACTION_SET:
3682                         stack->state = GUC_SET;
3683                         break;
3684                 case GUC_ACTION_LOCAL:
3685                         stack->state = GUC_LOCAL;
3686                         break;
3687                 case GUC_ACTION_SAVE:
3688                         stack->state = GUC_SAVE;
3689                         break;
3690         }
3691         stack->source = gconf->source;
3692         set_stack_value(gconf, &stack->prior);
3693
3694         gconf->stack = stack;
3695
3696         /* Ensure we remember to pop at end of xact */
3697         guc_dirty = true;
3698 }
3699
3700
3701 /*
3702  * Do GUC processing at main transaction start.
3703  */
3704 void
3705 AtStart_GUC(void)
3706 {
3707         /*
3708          * The nest level should be 0 between transactions; if it isn't, somebody
3709          * didn't call AtEOXact_GUC, or called it with the wrong nestLevel.  We
3710          * throw a warning but make no other effort to clean up.
3711          */
3712         if (GUCNestLevel != 0)
3713                 elog(WARNING, "GUC nest level = %d at transaction start",
3714                          GUCNestLevel);
3715         GUCNestLevel = 1;
3716 }
3717
3718 /*
3719  * Enter a new nesting level for GUC values.  This is called at subtransaction
3720  * start and when entering a function that has proconfig settings.      NOTE that
3721  * we must not risk error here, else subtransaction start will be unhappy.
3722  */
3723 int
3724 NewGUCNestLevel(void)
3725 {
3726         return ++GUCNestLevel;
3727 }
3728
3729 /*
3730  * Do GUC processing at transaction or subtransaction commit or abort, or
3731  * when exiting a function that has proconfig settings.  (The name is thus
3732  * a bit of a misnomer; perhaps it should be ExitGUCNestLevel or some such.)
3733  * During abort, we discard all GUC settings that were applied at nesting
3734  * levels >= nestLevel.  nestLevel == 1 corresponds to the main transaction.
3735  */
3736 void
3737 AtEOXact_GUC(bool isCommit, int nestLevel)
3738 {
3739         bool            still_dirty;
3740         int                     i;
3741
3742         Assert(nestLevel > 0 && nestLevel <= GUCNestLevel);
3743
3744         /* Quick exit if nothing's changed in this transaction */
3745         if (!guc_dirty)
3746         {
3747                 GUCNestLevel = nestLevel - 1;
3748                 return;
3749         }
3750
3751         still_dirty = false;
3752         for (i = 0; i < num_guc_variables; i++)
3753         {
3754                 struct config_generic *gconf = guc_variables[i];
3755                 GucStack   *stack;
3756
3757                 /*
3758                  * Process and pop each stack entry within the nest level.      To
3759                  * simplify fmgr_security_definer(), we allow failure exit from a
3760                  * function-with-SET-options to be recovered at the surrounding
3761                  * transaction or subtransaction abort; so there could be more than
3762                  * one stack entry to pop.
3763                  */
3764                 while ((stack = gconf->stack) != NULL &&
3765                            stack->nest_level >= nestLevel)
3766                 {
3767                         GucStack   *prev = stack->prev;
3768                         bool            restorePrior = false;
3769                         bool            restoreMasked = false;
3770                         bool            changed;
3771
3772                         /*
3773                          * In this next bit, if we don't set either restorePrior or
3774                          * restoreMasked, we must "discard" any unwanted fields of the
3775                          * stack entries to avoid leaking memory.  If we do set one of
3776                          * those flags, unused fields will be cleaned up after restoring.
3777                          */
3778                         if (!isCommit)          /* if abort, always restore prior value */
3779                                 restorePrior = true;
3780                         else if (stack->state == GUC_SAVE)
3781                                 restorePrior = true;
3782                         else if (stack->nest_level == 1)
3783                         {
3784                                 /* transaction commit */
3785                                 if (stack->state == GUC_SET_LOCAL)
3786                                         restoreMasked = true;
3787                                 else if (stack->state == GUC_SET)
3788                                 {
3789                                         /* we keep the current active value */
3790                                         discard_stack_value(gconf, &stack->prior);
3791                                 }
3792                                 else    /* must be GUC_LOCAL */
3793                                         restorePrior = true;
3794                         }
3795                         else if (prev == NULL ||
3796                                          prev->nest_level < stack->nest_level - 1)
3797                         {
3798                                 /* decrement entry's level and do not pop it */
3799                                 stack->nest_level--;
3800                                 continue;
3801                         }
3802                         else
3803                         {
3804                                 /*
3805                                  * We have to merge this stack entry into prev. See README for
3806                                  * discussion of this bit.
3807                                  */
3808                                 switch (stack->state)
3809                                 {
3810                                         case GUC_SAVE:
3811                                                 Assert(false);  /* can't get here */
3812
3813                                         case GUC_SET:
3814                                                 /* next level always becomes SET */
3815                                                 discard_stack_value(gconf, &stack->prior);
3816                                                 if (prev->state == GUC_SET_LOCAL)
3817                                                         discard_stack_value(gconf, &prev->masked);
3818                                                 prev->state = GUC_SET;
3819                                                 break;
3820
3821                                         case GUC_LOCAL:
3822                                                 if (prev->state == GUC_SET)
3823                                                 {
3824                                                         /* LOCAL migrates down */
3825                                                         prev->masked = stack->prior;
3826                                                         prev->state = GUC_SET_LOCAL;
3827                                                 }
3828                                                 else
3829                                                 {
3830                                                         /* else just forget this stack level */
3831                                                         discard_stack_value(gconf, &stack->prior);
3832                                                 }
3833                                                 break;
3834
3835                                         case GUC_SET_LOCAL:
3836                                                 /* prior state at this level no longer wanted */
3837                                                 discard_stack_value(gconf, &stack->prior);
3838                                                 /* copy down the masked state */
3839                                                 if (prev->state == GUC_SET_LOCAL)
3840                                                         discard_stack_value(gconf, &prev->masked);
3841                                                 prev->masked = stack->masked;
3842                                                 prev->state = GUC_SET_LOCAL;
3843                                                 break;
3844                                 }
3845                         }
3846
3847                         changed = false;
3848
3849                         if (restorePrior || restoreMasked)
3850                         {
3851                                 /* Perform appropriate restoration of the stacked value */
3852                                 union config_var_value newvalue;
3853                                 GucSource       newsource;
3854
3855                                 if (restoreMasked)
3856                                 {
3857                                         newvalue = stack->masked;
3858                                         newsource = PGC_S_SESSION;
3859                                 }
3860                                 else
3861                                 {
3862                                         newvalue = stack->prior;
3863                                         newsource = stack->source;
3864                                 }
3865
3866                                 switch (gconf->vartype)
3867                                 {
3868                                         case PGC_BOOL:
3869                                                 {
3870                                                         struct config_bool *conf = (struct config_bool *) gconf;
3871                                                         bool            newval = newvalue.boolval;
3872
3873                                                         if (*conf->variable != newval)
3874                                                         {
3875                                                                 if (conf->assign_hook)
3876                                                                         if (!(*conf->assign_hook) (newval,
3877                                                                                                            true, PGC_S_OVERRIDE))
3878                                                                                 elog(LOG, "failed to commit %s",
3879                                                                                          conf->gen.name);
3880                                                                 *conf->variable = newval;
3881                                                                 changed = true;
3882                                                         }
3883                                                         break;
3884                                                 }
3885                                         case PGC_INT:
3886                                                 {
3887                                                         struct config_int *conf = (struct config_int *) gconf;
3888                                                         int                     newval = newvalue.intval;
3889
3890                                                         if (*conf->variable != newval)
3891                                                         {
3892                                                                 if (conf->assign_hook)
3893                                                                         if (!(*conf->assign_hook) (newval,
3894                                                                                                            true, PGC_S_OVERRIDE))
3895                                                                                 elog(LOG, "failed to commit %s",
3896                                                                                          conf->gen.name);
3897                                                                 *conf->variable = newval;
3898                                                                 changed = true;
3899                                                         }
3900                                                         break;
3901                                                 }
3902                                         case PGC_REAL:
3903                                                 {
3904                                                         struct config_real *conf = (struct config_real *) gconf;
3905                                                         double          newval = newvalue.realval;
3906
3907                                                         if (*conf->variable != newval)
3908                                                         {
3909                                                                 if (conf->assign_hook)
3910                                                                         if (!(*conf->assign_hook) (newval,
3911                                                                                                            true, PGC_S_OVERRIDE))
3912                                                                                 elog(LOG, "failed to commit %s",
3913                                                                                          conf->gen.name);
3914                                                                 *conf->variable = newval;
3915                                                                 changed = true;
3916                                                         }
3917                                                         break;
3918                                                 }
3919                                         case PGC_STRING:
3920                                                 {
3921                                                         struct config_string *conf = (struct config_string *) gconf;
3922                                                         char       *newval = newvalue.stringval;
3923
3924                                                         if (*conf->variable != newval)
3925                                                         {
3926                                                                 if (conf->assign_hook && newval)
3927                                                                 {
3928                                                                         const char *newstr;
3929
3930                                                                         newstr = (*conf->assign_hook) (newval, true,
3931                                                                                                                          PGC_S_OVERRIDE);
3932                                                                         if (newstr == NULL)
3933                                                                                 elog(LOG, "failed to commit %s",
3934                                                                                          conf->gen.name);
3935                                                                         else if (newstr != newval)
3936                                                                         {
3937                                                                                 /*
3938                                                                                  * If newval should now be freed,
3939                                                                                  * it'll be taken care of below.
3940                                                                                  *
3941                                                                                  * See notes in set_config_option
3942                                                                                  * about casting
3943                                                                                  */
3944                                                                                 newval = (char *) newstr;
3945                                                                         }
3946                                                                 }
3947
3948                                                                 set_string_field(conf, conf->variable, newval);
3949                                                                 changed = true;
3950                                                         }
3951
3952                                                         /*
3953                                                          * Release stacked values if not used anymore. We
3954                                                          * could use discard_stack_value() here, but since
3955                                                          * we have type-specific code anyway, might as
3956                                                          * well inline it.
3957                                                          */
3958                                                         set_string_field(conf, &stack->prior.stringval, NULL);
3959                                                         set_string_field(conf, &stack->masked.stringval, NULL);
3960                                                         break;
3961                                                 }
3962                                         case PGC_ENUM:
3963                                                 {
3964                                                         struct config_enum *conf = (struct config_enum *) gconf;
3965                                                         int newval = newvalue.enumval;
3966
3967                                                         if (*conf->variable != newval)
3968                                                         {
3969                                                                 if (conf->assign_hook)
3970                                                                         if (!(*conf->assign_hook) (newval,
3971                                                                                                                            true, PGC_S_OVERRIDE))
3972                                                                                 elog(LOG, "failed to commit %s",
3973                                                                                          conf->gen.name);
3974                                                                 *conf->variable = newval;
3975                                                                 changed = true;
3976                                                         }
3977                                                         break;
3978                                                 }
3979                                 }
3980
3981                                 gconf->source = newsource;
3982                         }
3983
3984                         /* Finish popping the state stack */
3985                         gconf->stack = prev;
3986                         pfree(stack);
3987
3988                         /* Report new value if we changed it */
3989                         if (changed && (gconf->flags & GUC_REPORT))
3990                                 ReportGUCOption(gconf);
3991                 }                                               /* end of stack-popping loop */
3992
3993                 if (stack != NULL)
3994                         still_dirty = true;
3995         }
3996
3997         /* If there are no remaining stack entries, we can reset guc_dirty */
3998         guc_dirty = still_dirty;
3999
4000         /* Update nesting level */
4001         GUCNestLevel = nestLevel - 1;
4002 }
4003
4004
4005 /*
4006  * Start up automatic reporting of changes to variables marked GUC_REPORT.
4007  * This is executed at completion of backend startup.
4008  */
4009 void
4010 BeginReportingGUCOptions(void)
4011 {
4012         int                     i;
4013
4014         /*
4015          * Don't do anything unless talking to an interactive frontend of protocol
4016          * 3.0 or later.
4017          */
4018         if (whereToSendOutput != DestRemote ||
4019                 PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
4020                 return;
4021
4022         reporting_enabled = true;
4023
4024         /* Transmit initial values of interesting variables */
4025         for (i = 0; i < num_guc_variables; i++)
4026         {
4027                 struct config_generic *conf = guc_variables[i];
4028
4029                 if (conf->flags & GUC_REPORT)
4030                         ReportGUCOption(conf);
4031         }
4032 }
4033
4034 /*
4035  * ReportGUCOption: if appropriate, transmit option value to frontend
4036  */
4037 static void
4038 ReportGUCOption(struct config_generic * record)
4039 {
4040         if (reporting_enabled && (record->flags & GUC_REPORT))
4041         {
4042                 char       *val = _ShowOption(record, false);
4043                 StringInfoData msgbuf;
4044
4045                 pq_beginmessage(&msgbuf, 'S');
4046                 pq_sendstring(&msgbuf, record->name);
4047                 pq_sendstring(&msgbuf, val);
4048                 pq_endmessage(&msgbuf);
4049
4050                 pfree(val);
4051         }
4052 }
4053
4054
4055 /*
4056  * Try to interpret value as boolean value.  Valid values are: true,
4057  * false, yes, no, on, off, 1, 0; as well as unique prefixes thereof.
4058  * If the string parses okay, return true, else false.
4059  * If okay and result is not NULL, return the value in *result.
4060  */
4061 bool
4062 parse_bool(const char *value, bool *result)
4063 {
4064         size_t          len = strlen(value);
4065
4066         if (pg_strncasecmp(value, "true", len) == 0)
4067         {
4068                 if (result)
4069                         *result = true;
4070         }
4071         else if (pg_strncasecmp(value, "false", len) == 0)
4072         {
4073                 if (result)
4074                         *result = false;
4075         }
4076
4077         else if (pg_strncasecmp(value, "yes", len) == 0)
4078         {
4079                 if (result)
4080                         *result = true;
4081         }
4082         else if (pg_strncasecmp(value, "no", len) == 0)
4083         {
4084                 if (result)
4085                         *result = false;
4086         }
4087
4088         /* 'o' is not unique enough */
4089         else if (pg_strncasecmp(value, "on", (len > 2 ? len : 2)) == 0)
4090         {
4091                 if (result)
4092                         *result = true;
4093         }
4094         else if (pg_strncasecmp(value, "off", (len > 2 ? len : 2)) == 0)
4095         {
4096                 if (result)
4097                         *result = false;
4098         }
4099
4100         else if (pg_strcasecmp(value, "1") == 0)
4101         {
4102                 if (result)
4103                         *result = true;
4104         }
4105         else if (pg_strcasecmp(value, "0") == 0)
4106         {
4107                 if (result)
4108                         *result = false;
4109         }
4110
4111         else
4112         {
4113                 if (result)
4114                         *result = false;        /* suppress compiler warning */
4115                 return false;
4116         }
4117         return true;
4118 }
4119
4120
4121
4122 /*
4123  * Try to parse value as an integer.  The accepted formats are the
4124  * usual decimal, octal, or hexadecimal formats, optionally followed by
4125  * a unit name if "flags" indicates a unit is allowed.
4126  *
4127  * If the string parses okay, return true, else false.
4128  * If okay and result is not NULL, return the value in *result.
4129  * If not okay and hintmsg is not NULL, *hintmsg is set to a suitable
4130  *      HINT message, or NULL if no hint provided.
4131  */
4132 bool
4133 parse_int(const char *value, int *result, int flags, const char **hintmsg)
4134 {
4135         int64           val;
4136         char       *endptr;
4137
4138         /* To suppress compiler warnings, always set output params */
4139         if (result)
4140                 *result = 0;
4141         if (hintmsg)
4142                 *hintmsg = NULL;
4143
4144         /* We assume here that int64 is at least as wide as long */
4145         errno = 0;
4146         val = strtol(value, &endptr, 0);
4147
4148         if (endptr == value)
4149                 return false;                   /* no HINT for integer syntax error */
4150
4151         if (errno == ERANGE || val != (int64) ((int32) val))
4152         {
4153                 if (hintmsg)
4154                         *hintmsg = gettext_noop("Value exceeds integer range.");
4155                 return false;
4156         }
4157
4158         /* allow whitespace between integer and unit */
4159         while (isspace((unsigned char) *endptr))
4160                 endptr++;
4161
4162         /* Handle possible unit */
4163         if (*endptr != '\0')
4164         {
4165                 /*
4166                  * Note: the multiple-switch coding technique here is a bit tedious,
4167                  * but seems necessary to avoid intermediate-value overflows.
4168                  *
4169                  * If INT64_IS_BUSTED (ie, it's really int32) we will fail to detect
4170                  * overflow due to units conversion, but there are few enough such
4171                  * machines that it does not seem worth trying to be smarter.
4172                  */
4173                 if (flags & GUC_UNIT_MEMORY)
4174                 {
4175                         /* Set hint for use if no match or trailing garbage */
4176                         if (hintmsg)
4177                                 *hintmsg = gettext_noop("Valid units for this parameter are \"kB\", \"MB\", and \"GB\".");
4178
4179 #if BLCKSZ < 1024 || BLCKSZ > (1024*1024)
4180 #error BLCKSZ must be between 1KB and 1MB
4181 #endif
4182 #if XLOG_BLCKSZ < 1024 || XLOG_BLCKSZ > (1024*1024)
4183 #error XLOG_BLCKSZ must be between 1KB and 1MB
4184 #endif
4185
4186                         if (strncmp(endptr, "kB", 2) == 0)
4187                         {
4188                                 endptr += 2;
4189                                 switch (flags & GUC_UNIT_MEMORY)
4190                                 {
4191                                         case GUC_UNIT_BLOCKS:
4192                                                 val /= (BLCKSZ / 1024);
4193                                                 break;
4194                                         case GUC_UNIT_XBLOCKS:
4195                                                 val /= (XLOG_BLCKSZ / 1024);
4196                                                 break;
4197                                 }
4198                         }
4199                         else if (strncmp(endptr, "MB", 2) == 0)
4200                         {
4201                                 endptr += 2;
4202                                 switch (flags & GUC_UNIT_MEMORY)
4203                                 {
4204                                         case GUC_UNIT_KB:
4205                                                 val *= KB_PER_MB;
4206                                                 break;
4207                                         case GUC_UNIT_BLOCKS:
4208                                                 val *= KB_PER_MB / (BLCKSZ / 1024);
4209                                                 break;
4210                                         case GUC_UNIT_XBLOCKS:
4211                                                 val *= KB_PER_MB / (XLOG_BLCKSZ / 1024);
4212                                                 break;
4213                                 }
4214                         }
4215                         else if (strncmp(endptr, "GB", 2) == 0)
4216                         {
4217                                 endptr += 2;
4218                                 switch (flags & GUC_UNIT_MEMORY)
4219                                 {
4220                                         case GUC_UNIT_KB:
4221                                                 val *= KB_PER_GB;
4222                                                 break;
4223                                         case GUC_UNIT_BLOCKS:
4224                                                 val *= KB_PER_GB / (BLCKSZ / 1024);
4225                                                 break;
4226                                         case GUC_UNIT_XBLOCKS:
4227                                                 val *= KB_PER_GB / (XLOG_BLCKSZ / 1024);
4228                                                 break;
4229                                 }
4230                         }
4231                 }
4232                 else if (flags & GUC_UNIT_TIME)
4233                 {
4234                         /* Set hint for use if no match or trailing garbage */
4235                         if (hintmsg)
4236                                 *hintmsg = gettext_noop("Valid units for this parameter are \"ms\", \"s\", \"min\", \"h\", and \"d\".");
4237
4238                         if (strncmp(endptr, "ms", 2) == 0)
4239                         {
4240                                 endptr += 2;
4241                                 switch (flags & GUC_UNIT_TIME)
4242                                 {
4243                                         case GUC_UNIT_S:
4244                                                 val /= MS_PER_S;
4245                                                 break;
4246                                         case GUC_UNIT_MIN:
4247                                                 val /= MS_PER_MIN;
4248                                                 break;
4249                                 }
4250                         }
4251                         else if (strncmp(endptr, "s", 1) == 0)
4252                         {
4253                                 endptr += 1;
4254                                 switch (flags & GUC_UNIT_TIME)
4255                                 {
4256                                         case GUC_UNIT_MS:
4257                                                 val *= MS_PER_S;
4258                                                 break;
4259                                         case GUC_UNIT_MIN:
4260                                                 val /= S_PER_MIN;
4261                                                 break;
4262                                 }
4263                         }
4264                         else if (strncmp(endptr, "min", 3) == 0)
4265                         {
4266                                 endptr += 3;
4267                                 switch (flags & GUC_UNIT_TIME)
4268                                 {
4269                                         case GUC_UNIT_MS:
4270                                                 val *= MS_PER_MIN;
4271                                                 break;
4272                                         case GUC_UNIT_S:
4273                                                 val *= S_PER_MIN;
4274                                                 break;
4275                                 }
4276                         }
4277                         else if (strncmp(endptr, "h", 1) == 0)
4278                         {
4279                                 endptr += 1;
4280                                 switch (flags & GUC_UNIT_TIME)
4281                                 {
4282                                         case GUC_UNIT_MS:
4283                                                 val *= MS_PER_H;
4284                                                 break;
4285                                         case GUC_UNIT_S:
4286                                                 val *= S_PER_H;
4287                                                 break;
4288                                         case GUC_UNIT_MIN:
4289                                                 val *= MIN_PER_H;
4290                                                 break;
4291                                 }
4292                         }
4293                         else if (strncmp(endptr, "d", 1) == 0)
4294                         {
4295                                 endptr += 1;
4296                                 switch (flags & GUC_UNIT_TIME)
4297                                 {
4298                                         case GUC_UNIT_MS:
4299                                                 val *= MS_PER_D;
4300                                                 break;
4301                                         case GUC_UNIT_S:
4302                                                 val *= S_PER_D;
4303                                                 break;
4304                                         case GUC_UNIT_MIN:
4305                                                 val *= MIN_PER_D;
4306                                                 break;
4307                                 }
4308                         }
4309                 }
4310
4311                 /* allow whitespace after unit */
4312                 while (isspace((unsigned char) *endptr))
4313                         endptr++;
4314
4315                 if (*endptr != '\0')
4316                         return false;           /* appropriate hint, if any, already set */
4317
4318                 /* Check for overflow due to units conversion */
4319                 if (val != (int64) ((int32) val))
4320                 {
4321                         if (hintmsg)
4322                                 *hintmsg = gettext_noop("Value exceeds integer range.");
4323                         return false;
4324                 }
4325         }
4326
4327         if (result)
4328                 *result = (int) val;
4329         return true;
4330 }
4331
4332
4333
4334 /*
4335  * Try to parse value as a floating point number in the usual format.
4336  * If the string parses okay, return true, else false.
4337  * If okay and result is not NULL, return the value in *result.
4338  */
4339 bool
4340 parse_real(const char *value, double *result)
4341 {
4342         double          val;
4343         char       *endptr;
4344
4345         if (result)
4346                 *result = 0;                    /* suppress compiler warning */
4347
4348         errno = 0;
4349         val = strtod(value, &endptr);
4350         if (endptr == value || errno == ERANGE)
4351                 return false;
4352
4353         /* allow whitespace after number */
4354         while (isspace((unsigned char) *endptr))
4355                 endptr++;
4356         if (*endptr != '\0')
4357                 return false;
4358
4359         if (result)
4360                 *result = val;
4361         return true;
4362 }
4363
4364
4365 /*
4366  * Lookup the name for an enum option with the selected value.
4367  * Should only ever be called with known-valid values, so throws
4368  * an elog(ERROR) if the enum option is not found.
4369  *
4370  * The returned string is a pointer to static data and not
4371  * allocated for modification.
4372  */
4373 const char *
4374 config_enum_lookup_by_value(struct config_enum *record, int val)
4375 {
4376         const struct config_enum_entry *entry = record->options;
4377         while (entry && entry->name)
4378         {
4379                 if (entry->val == val)
4380                         return entry->name;
4381                 entry++;
4382         }
4383         elog(ERROR, "could not find enum option %d for %s",
4384                  val, record->gen.name);
4385         return NULL; /* silence compiler */
4386 }
4387
4388
4389 /*
4390  * Lookup the value for an enum option with the selected name
4391  * (case-insensitive).
4392  * If the enum option is found, sets the retval value and returns
4393  * true. If it's not found, return FALSE and retval is set to 0.
4394  *
4395  */
4396 bool
4397 config_enum_lookup_by_name(struct config_enum *record, const char *value, int *retval)
4398 {
4399         const struct config_enum_entry *entry = record->options;
4400
4401         if (retval)
4402                 *retval = 0;                    /* suppress compiler warning */
4403
4404         while (entry && entry->name)
4405         {
4406                 if (pg_strcasecmp(value, entry->name) == 0)
4407                 {
4408                         *retval = entry->val;
4409                         return TRUE;
4410                 }
4411                 entry++;
4412         }
4413         return FALSE;
4414 }
4415
4416
4417 /*
4418  * Return a list of all available options for an enum, excluding
4419  * hidden ones, separated by ", " (comma-space).
4420  * If prefix is non-NULL, it is added before the first enum value.
4421  * If suffix is non-NULL, it is added to the end of the string.
4422  */
4423 static char *
4424 config_enum_get_options(struct config_enum *record, const char *prefix, const char *suffix)
4425 {
4426         const struct config_enum_entry *entry = record->options;
4427         int             len = 0;
4428         char   *hintmsg;
4429
4430         if (!entry || !entry->name)
4431                 return NULL;                                    /* Should not happen */
4432
4433         while (entry && entry->name)
4434         {
4435                 if (!entry->hidden)
4436                         len += strlen(entry->name) + 2; /* string and ", " */
4437
4438                 entry++;
4439         }
4440
4441         hintmsg = palloc(len + strlen(prefix) + strlen(suffix) + 2);
4442
4443         strcpy(hintmsg, prefix);
4444
4445         entry = record->options;
4446         while (entry && entry->name)
4447         {
4448                 if (!entry->hidden)
4449                 {
4450                         strcat(hintmsg, entry->name);
4451                         strcat(hintmsg, ", ");
4452                 }
4453
4454                 entry++;
4455         }
4456
4457         len = strlen(hintmsg);
4458
4459         /*
4460          * All the entries may have been hidden, leaving the string empty
4461          * if no prefix was given. This indicates a broken GUC setup, since
4462          * there is no use for an enum without any values, so we just check
4463          * to make sure we don't write to invalid memory instead of actually
4464          * trying to do something smart with it.
4465          */
4466         if (len > 1)
4467                 /* Replace final comma/space */
4468                 hintmsg[len-2] = '\0';
4469
4470         strcat(hintmsg, suffix);
4471
4472         return hintmsg;
4473 }
4474
4475
4476 /*
4477  * Call a GucStringAssignHook function, being careful to free the
4478  * "newval" string if the hook ereports.
4479  *
4480  * This is split out of set_config_option just to avoid the "volatile"
4481  * qualifiers that would otherwise have to be plastered all over.
4482  */
4483 static const char *
4484 call_string_assign_hook(GucStringAssignHook assign_hook,
4485                                                 char *newval, bool doit, GucSource source)
4486 {
4487         const char *result;
4488
4489         PG_TRY();
4490         {
4491                 result = (*assign_hook) (newval, doit, source);
4492         }
4493         PG_CATCH();
4494         {
4495                 free(newval);
4496                 PG_RE_THROW();
4497         }
4498         PG_END_TRY();
4499
4500         return result;
4501 }
4502
4503
4504 /*
4505  * Sets option `name' to given value. The value should be a string
4506  * which is going to be parsed and converted to the appropriate data
4507  * type.  The context and source parameters indicate in which context this
4508  * function is being called so it can apply the access restrictions
4509  * properly.
4510  *
4511  * If value is NULL, set the option to its default value (normally the
4512  * reset_val, but if source == PGC_S_DEFAULT we instead use the boot_val).
4513  *
4514  * action indicates whether to set the value globally in the session, locally
4515  * to the current top transaction, or just for the duration of a function call.
4516  *
4517  * If changeVal is false then don't really set the option but do all
4518  * the checks to see if it would work.
4519  *
4520  * If there is an error (non-existing option, invalid value) then an
4521  * ereport(ERROR) is thrown *unless* this is called in a context where we
4522  * don't want to ereport (currently, startup or SIGHUP config file reread).
4523  * In that case we write a suitable error message via ereport(LOG) and
4524  * return false. This is working around the deficiencies in the ereport
4525  * mechanism, so don't blame me.  In all other cases, the function
4526  * returns true, including cases where the input is valid but we chose
4527  * not to apply it because of context or source-priority considerations.
4528  *
4529  * See also SetConfigOption for an external interface.
4530  */
4531 bool
4532 set_config_option(const char *name, const char *value,
4533                                   GucContext context, GucSource source,
4534                                   GucAction action, bool changeVal)
4535 {
4536         struct config_generic *record;
4537         int                     elevel;
4538         bool            makeDefault;
4539
4540         if (context == PGC_SIGHUP || source == PGC_S_DEFAULT)
4541         {
4542                 /*
4543                  * To avoid cluttering the log, only the postmaster bleats loudly
4544                  * about problems with the config file.
4545                  */
4546                 elevel = IsUnderPostmaster ? DEBUG3 : LOG;
4547         }
4548         else if (source == PGC_S_DATABASE || source == PGC_S_USER)
4549                 elevel = INFO;
4550         else
4551                 elevel = ERROR;
4552
4553         record = find_option(name, true, elevel);
4554         if (record == NULL)
4555         {
4556                 ereport(elevel,
4557                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
4558                            errmsg("unrecognized configuration parameter \"%s\"", name)));
4559                 return false;
4560         }
4561
4562         /*
4563          * If source is postgresql.conf, mark the found record with
4564          * GUC_IS_IN_FILE. This is for the convenience of ProcessConfigFile.  Note
4565          * that we do it even if changeVal is false, since ProcessConfigFile wants
4566          * the marking to occur during its testing pass.
4567          */
4568         if (source == PGC_S_FILE)
4569                 record->status |= GUC_IS_IN_FILE;
4570
4571         /*
4572          * Check if the option can be set at this time. See guc.h for the precise
4573          * rules. Note that we don't want to throw errors if we're in the SIGHUP
4574          * context. In that case we just ignore the attempt and return true.
4575          */
4576         switch (record->context)
4577         {
4578                 case PGC_INTERNAL:
4579                         if (context == PGC_SIGHUP)
4580                                 return true;
4581                         if (context != PGC_INTERNAL)
4582                         {
4583                                 ereport(elevel,
4584                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4585                                                  errmsg("parameter \"%s\" cannot be changed",
4586                                                                 name)));
4587                                 return false;
4588                         }
4589                         break;
4590                 case PGC_POSTMASTER:
4591                         if (context == PGC_SIGHUP)
4592                         {
4593                                 /*
4594                                  * We are reading a PGC_POSTMASTER var from postgresql.conf.
4595                                  * We can't change the setting, so give a warning if the DBA
4596                                  * tries to change it.  (Throwing an error would be more
4597                                  * consistent, but seems overly rigid.)
4598                                  */
4599                                 if (changeVal && !is_newvalue_equal(record, value))
4600                                         ereport(elevel,
4601                                                         (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4602                                                          errmsg("attempted change of parameter \"%s\" ignored",
4603                                                                         name),
4604                                                          errdetail("This parameter cannot be changed after server start.")));
4605                                 return true;
4606                         }
4607                         if (context != PGC_POSTMASTER)
4608                         {
4609                                 ereport(elevel,
4610                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4611                                                  errmsg("attempted change of parameter \"%s\" ignored",
4612                                                                 name),
4613                                                  errdetail("This parameter cannot be changed after server start.")));
4614                                 return false;
4615                         }
4616                         break;
4617                 case PGC_SIGHUP:
4618                         if (context != PGC_SIGHUP && context != PGC_POSTMASTER)
4619                         {
4620                                 ereport(elevel,
4621                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4622                                                  errmsg("parameter \"%s\" cannot be changed now",
4623                                                                 name)));
4624                                 return false;
4625                         }
4626
4627                         /*
4628                          * Hmm, the idea of the SIGHUP context is "ought to be global, but
4629                          * can be changed after postmaster start". But there's nothing
4630                          * that prevents a crafty administrator from sending SIGHUP
4631                          * signals to individual backends only.
4632                          */
4633                         break;
4634                 case PGC_BACKEND:
4635                         if (context == PGC_SIGHUP)
4636                         {
4637                                 /*
4638                                  * If a PGC_BACKEND parameter is changed in the config file,
4639                                  * we want to accept the new value in the postmaster (whence
4640                                  * it will propagate to subsequently-started backends), but
4641                                  * ignore it in existing backends.      This is a tad klugy, but
4642                                  * necessary because we don't re-read the config file during
4643                                  * backend start.
4644                                  */
4645                                 if (IsUnderPostmaster)
4646                                         return true;
4647                         }
4648                         else if (context != PGC_BACKEND && context != PGC_POSTMASTER)
4649                         {
4650                                 ereport(elevel,
4651                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4652                                                  errmsg("parameter \"%s\" cannot be set after connection start",
4653                                                                 name)));
4654                                 return false;
4655                         }
4656                         break;
4657                 case PGC_SUSET:
4658                         if (context == PGC_USERSET || context == PGC_BACKEND)
4659                         {
4660                                 ereport(elevel,
4661                                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
4662                                                  errmsg("permission denied to set parameter \"%s\"",
4663                                                                 name)));
4664                                 return false;
4665                         }
4666                         break;
4667                 case PGC_USERSET:
4668                         /* always okay */
4669                         break;
4670         }
4671
4672         /*
4673          * Should we set reset/stacked values?  (If so, the behavior is not
4674          * transactional.)      This is done either when we get a default value from
4675          * the database's/user's/client's default settings or when we reset a
4676          * value to its default.
4677          */
4678         makeDefault = changeVal && (source <= PGC_S_OVERRIDE) &&
4679                 ((value != NULL) || source == PGC_S_DEFAULT);
4680
4681         /*
4682          * Ignore attempted set if overridden by previously processed setting.
4683          * However, if changeVal is false then plow ahead anyway since we are
4684          * trying to find out if the value is potentially good, not actually use
4685          * it. Also keep going if makeDefault is true, since we may want to set
4686          * the reset/stacked values even if we can't set the variable itself.
4687          */
4688         if (record->source > source)
4689         {
4690                 if (changeVal && !makeDefault)
4691                 {
4692                         elog(DEBUG3, "\"%s\": setting ignored because previous source is higher priority",
4693                                  name);
4694                         return true;
4695                 }
4696                 changeVal = false;
4697         }
4698
4699         /*
4700          * Evaluate value and set variable.
4701          */
4702         switch (record->vartype)
4703         {
4704                 case PGC_BOOL:
4705                         {
4706                                 struct config_bool *conf = (struct config_bool *) record;
4707                                 bool            newval;
4708
4709                                 if (value)
4710                                 {
4711                                         if (!parse_bool(value, &newval))
4712                                         {
4713                                                 ereport(elevel,
4714                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4715                                                   errmsg("parameter \"%s\" requires a Boolean value",
4716                                                                  name)));
4717                                                 return false;
4718                                         }
4719                                 }
4720                                 else if (source == PGC_S_DEFAULT)
4721                                         newval = conf->boot_val;
4722                                 else
4723                                 {
4724                                         newval = conf->reset_val;
4725                                         source = conf->gen.reset_source;
4726                                 }
4727
4728                                 /* Save old value to support transaction abort */
4729                                 if (changeVal && !makeDefault)
4730                                         push_old_value(&conf->gen, action);
4731
4732                                 if (conf->assign_hook)
4733                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4734                                         {
4735                                                 ereport(elevel,
4736                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4737                                                          errmsg("invalid value for parameter \"%s\": %d",
4738                                                                         name, (int) newval)));
4739                                                 return false;
4740                                         }
4741
4742                                 if (changeVal)
4743                                 {
4744                                         *conf->variable = newval;
4745                                         conf->gen.source = source;
4746                                 }
4747                                 if (makeDefault)
4748                                 {
4749                                         GucStack   *stack;
4750
4751                                         if (conf->gen.reset_source <= source)
4752                                         {
4753                                                 conf->reset_val = newval;
4754                                                 conf->gen.reset_source = source;
4755                                         }
4756                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4757                                         {
4758                                                 if (stack->source <= source)
4759                                                 {
4760                                                         stack->prior.boolval = newval;
4761                                                         stack->source = source;
4762                                                 }
4763                                         }
4764                                 }
4765                                 break;
4766                         }
4767
4768                 case PGC_INT:
4769                         {
4770                                 struct config_int *conf = (struct config_int *) record;
4771                                 int                     newval;
4772
4773                                 if (value)
4774                                 {
4775                                         const char *hintmsg;
4776
4777                                         if (!parse_int(value, &newval, conf->gen.flags, &hintmsg))
4778                                         {
4779                                                 ereport(elevel,
4780                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4781                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
4782                                                                 name, value),
4783                                                                  hintmsg ? errhint(hintmsg) : 0));
4784                                                 return false;
4785                                         }
4786                                         if (newval < conf->min || newval > conf->max)
4787                                         {
4788                                                 ereport(elevel,
4789                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4790                                                                  errmsg("%d is outside the valid range for parameter \"%s\" (%d .. %d)",
4791                                                                                 newval, name, conf->min, conf->max)));
4792                                                 return false;
4793                                         }
4794                                 }
4795                                 else if (source == PGC_S_DEFAULT)
4796                                         newval = conf->boot_val;
4797                                 else
4798                                 {
4799                                         newval = conf->reset_val;
4800                                         source = conf->gen.reset_source;
4801                                 }
4802
4803                                 /* Save old value to support transaction abort */
4804                                 if (changeVal && !makeDefault)
4805                                         push_old_value(&conf->gen, action);
4806
4807                                 if (conf->assign_hook)
4808                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4809                                         {
4810                                                 ereport(elevel,
4811                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4812                                                          errmsg("invalid value for parameter \"%s\": %d",
4813                                                                         name, newval)));
4814                                                 return false;
4815                                         }
4816
4817                                 if (changeVal)
4818                                 {
4819                                         *conf->variable = newval;
4820                                         conf->gen.source = source;
4821                                 }
4822                                 if (makeDefault)
4823                                 {
4824                                         GucStack   *stack;
4825
4826                                         if (conf->gen.reset_source <= source)
4827                                         {
4828                                                 conf->reset_val = newval;
4829                                                 conf->gen.reset_source = source;
4830                                         }
4831                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4832                                         {
4833                                                 if (stack->source <= source)
4834                                                 {
4835                                                         stack->prior.intval = newval;
4836                                                         stack->source = source;
4837                                                 }
4838                                         }
4839                                 }
4840                                 break;
4841                         }
4842
4843                 case PGC_REAL:
4844                         {
4845                                 struct config_real *conf = (struct config_real *) record;
4846                                 double          newval;
4847
4848                                 if (value)
4849                                 {
4850                                         if (!parse_real(value, &newval))
4851                                         {
4852                                                 ereport(elevel,
4853                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4854                                                   errmsg("parameter \"%s\" requires a numeric value",
4855                                                                  name)));
4856                                                 return false;
4857                                         }
4858                                         if (newval < conf->min || newval > conf->max)
4859                                         {
4860                                                 ereport(elevel,
4861                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4862                                                                  errmsg("%g is outside the valid range for parameter \"%s\" (%g .. %g)",
4863                                                                                 newval, name, conf->min, conf->max)));
4864                                                 return false;
4865                                         }
4866                                 }
4867                                 else if (source == PGC_S_DEFAULT)
4868                                         newval = conf->boot_val;
4869                                 else
4870                                 {
4871                                         newval = conf->reset_val;
4872                                         source = conf->gen.reset_source;
4873                                 }
4874
4875                                 /* Save old value to support transaction abort */
4876                                 if (changeVal && !makeDefault)
4877                                         push_old_value(&conf->gen, action);
4878
4879                                 if (conf->assign_hook)
4880                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4881                                         {
4882                                                 ereport(elevel,
4883                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4884                                                          errmsg("invalid value for parameter \"%s\": %g",
4885                                                                         name, newval)));
4886                                                 return false;
4887                                         }
4888
4889                                 if (changeVal)
4890                                 {
4891                                         *conf->variable = newval;
4892                                         conf->gen.source = source;
4893                                 }
4894                                 if (makeDefault)
4895                                 {
4896                                         GucStack   *stack;
4897
4898                                         if (conf->gen.reset_source <= source)
4899                                         {
4900                                                 conf->reset_val = newval;
4901                                                 conf->gen.reset_source = source;
4902                                         }
4903                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4904                                         {
4905                                                 if (stack->source <= source)
4906                                                 {
4907                                                         stack->prior.realval = newval;
4908                                                         stack->source = source;
4909                                                 }
4910                                         }
4911                                 }
4912                                 break;
4913                         }
4914
4915                 case PGC_STRING:
4916                         {
4917                                 struct config_string *conf = (struct config_string *) record;
4918                                 char       *newval;
4919
4920                                 if (value)
4921                                 {
4922                                         newval = guc_strdup(elevel, value);
4923                                         if (newval == NULL)
4924                                                 return false;
4925
4926                                         /*
4927                                          * The only sort of "parsing" check we need to do is apply
4928                                          * truncation if GUC_IS_NAME.
4929                                          */
4930                                         if (conf->gen.flags & GUC_IS_NAME)
4931                                                 truncate_identifier(newval, strlen(newval), true);
4932                                 }
4933                                 else if (source == PGC_S_DEFAULT)
4934                                 {
4935                                         if (conf->boot_val == NULL)
4936                                                 newval = NULL;
4937                                         else
4938                                         {
4939                                                 newval = guc_strdup(elevel, conf->boot_val);
4940                                                 if (newval == NULL)
4941                                                         return false;
4942                                         }
4943                                 }
4944                                 else
4945                                 {
4946                                         /*
4947                                          * We could possibly avoid strdup here, but easier to make
4948                                          * this case work the same as the normal assignment case;
4949                                          * note the possible free of newval below.
4950                                          */
4951                                         if (conf->reset_val == NULL)
4952                                                 newval = NULL;
4953                                         else
4954                                         {
4955                                                 newval = guc_strdup(elevel, conf->reset_val);
4956                                                 if (newval == NULL)
4957                                                         return false;
4958                                         }
4959                                         source = conf->gen.reset_source;
4960                                 }
4961
4962                                 /* Save old value to support transaction abort */
4963                                 if (changeVal && !makeDefault)
4964                                         push_old_value(&conf->gen, action);
4965
4966                                 if (conf->assign_hook && newval)
4967                                 {
4968                                         const char *hookresult;
4969
4970                                         /*
4971                                          * If the hook ereports, we have to make sure we free
4972                                          * newval, else it will be a permanent memory leak.
4973                                          */
4974                                         hookresult = call_string_assign_hook(conf->assign_hook,
4975                                                                                                                  newval,
4976                                                                                                                  changeVal,
4977                                                                                                                  source);
4978                                         if (hookresult == NULL)
4979                                         {
4980                                                 free(newval);
4981                                                 ereport(elevel,
4982                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4983                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
4984                                                                 name, value ? value : "")));
4985                                                 return false;
4986                                         }
4987                                         else if (hookresult != newval)
4988                                         {
4989                                                 free(newval);
4990
4991                                                 /*
4992                                                  * Having to cast away const here is annoying, but the
4993                                                  * alternative is to declare assign_hooks as returning
4994                                                  * char*, which would mean they'd have to cast away
4995                                                  * const, or as both taking and returning char*, which
4996                                                  * doesn't seem attractive either --- we don't want
4997                                                  * them to scribble on the passed str.
4998                                                  */
4999                                                 newval = (char *) hookresult;
5000                                         }
5001                                 }
5002
5003                                 if (changeVal)
5004                                 {
5005                                         set_string_field(conf, conf->variable, newval);
5006                                         conf->gen.source = source;
5007                                 }
5008                                 if (makeDefault)
5009                                 {
5010                                         GucStack   *stack;
5011
5012                                         if (conf->gen.reset_source <= source)
5013                                         {
5014                                                 set_string_field(conf, &conf->reset_val, newval);
5015                                                 conf->gen.reset_source = source;
5016                                         }
5017                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
5018                                         {
5019                                                 if (stack->source <= source)
5020                                                 {
5021                                                         set_string_field(conf, &stack->prior.stringval,
5022                                                                                          newval);
5023                                                         stack->source = source;
5024                                                 }
5025                                         }
5026                                 }
5027                                 /* Perhaps we didn't install newval anywhere */
5028                                 if (newval && !string_field_used(conf, newval))
5029                                         free(newval);
5030                                 break;
5031                         }
5032                 case PGC_ENUM:
5033                         {
5034                                 struct config_enum *conf = (struct config_enum *) record;
5035                                 int                     newval;
5036
5037                                 if (value)
5038                                 {
5039                                         if (!config_enum_lookup_by_name(conf, value, &newval))
5040                                         {
5041                                                 char *hintmsg = config_enum_get_options(conf, "Available values: ", ".");
5042
5043                                                 ereport(elevel,
5044                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5045                                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
5046                                                                                 name, value),
5047                                                                  hintmsg ? errhint(hintmsg) : 0));
5048
5049                                                 if (hintmsg)
5050                                                         pfree(hintmsg);
5051                                                 return false;
5052                                         }
5053                                 }
5054                                 else if (source == PGC_S_DEFAULT)
5055                                         newval = conf->boot_val;
5056                                 else
5057                                 {
5058                                         newval = conf->reset_val;
5059                                         source = conf->gen.reset_source;
5060                                 }
5061
5062                                 /* Save old value to support transaction abort */
5063                                 if (changeVal && !makeDefault)
5064                                         push_old_value(&conf->gen, action);
5065
5066                                 if (conf->assign_hook)
5067                                         if (!(*conf->assign_hook) (newval, changeVal, source))
5068                                         {
5069                                                 ereport(elevel,
5070                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5071                                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
5072                                                                                 name,
5073                                                                                 config_enum_lookup_by_value(conf, newval))));
5074                                                 return false;
5075                                         }
5076
5077                                 if (changeVal)
5078                                 {
5079                                         *conf->variable = newval;
5080                                         conf->gen.source = source;
5081                                 }
5082                                 if (makeDefault)
5083                                 {
5084                                         GucStack   *stack;
5085
5086                                         if (conf->gen.reset_source <= source)
5087                                         {
5088                                                 conf->reset_val = newval;
5089                                                 conf->gen.reset_source = source;
5090                                         }
5091                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
5092                                         {
5093                                                 if (stack->source <= source)
5094                                                 {
5095                                                         stack->prior.enumval = newval;
5096                                                         stack->source = source;
5097                                                 }
5098                                         }
5099                                 }
5100                                 break;
5101                         }
5102         }
5103
5104         if (changeVal && (record->flags & GUC_REPORT))
5105                 ReportGUCOption(record);
5106
5107         return true;
5108 }
5109
5110
5111 /*
5112  * Set the fields for source file and line number the setting came from.
5113  */
5114 static void
5115 set_config_sourcefile(const char *name, char *sourcefile, int sourceline)
5116 {
5117         struct config_generic *record;
5118         int                     elevel;
5119
5120         /*
5121          * To avoid cluttering the log, only the postmaster bleats loudly
5122          * about problems with the config file.
5123          */
5124         elevel = IsUnderPostmaster ? DEBUG3 : LOG;
5125
5126         record = find_option(name, true, elevel);
5127         /* should not happen */
5128         if (record == NULL)
5129                 elog(ERROR, "unrecognized configuration parameter \"%s\"", name);
5130
5131         if (record->sourcefile)
5132                 free(record->sourcefile);
5133         record->sourcefile = guc_strdup(elevel, sourcefile);
5134         record->sourceline = sourceline;
5135 }
5136
5137 /*
5138  * Set a config option to the given value. See also set_config_option,
5139  * this is just the wrapper to be called from outside GUC.      NB: this
5140  * is used only for non-transactional operations.
5141  *
5142  * Note: there is no support here for setting source file/line, as it
5143  * is currently not needed.
5144  */
5145 void
5146 SetConfigOption(const char *name, const char *value,
5147                                 GucContext context, GucSource source)
5148 {
5149         (void) set_config_option(name, value, context, source,
5150                                                          GUC_ACTION_SET, true);
5151 }
5152
5153
5154
5155 /*
5156  * Fetch the current value of the option `name'. If the option doesn't exist,
5157  * throw an ereport and don't return.
5158  *
5159  * The string is *not* allocated for modification and is really only
5160  * valid until the next call to configuration related functions.
5161  */
5162 const char *
5163 GetConfigOption(const char *name)
5164 {
5165         struct config_generic *record;
5166         static char buffer[256];
5167
5168         record = find_option(name, false, ERROR);
5169         if (record == NULL)
5170                 ereport(ERROR,
5171                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5172                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5173         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
5174                 ereport(ERROR,
5175                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5176                                  errmsg("must be superuser to examine \"%s\"", name)));
5177
5178         switch (record->vartype)
5179         {
5180                 case PGC_BOOL:
5181                         return *((struct config_bool *) record)->variable ? "on" : "off";
5182
5183                 case PGC_INT:
5184                         snprintf(buffer, sizeof(buffer), "%d",
5185                                          *((struct config_int *) record)->variable);
5186                         return buffer;
5187
5188                 case PGC_REAL:
5189                         snprintf(buffer, sizeof(buffer), "%g",
5190                                          *((struct config_real *) record)->variable);
5191                         return buffer;
5192
5193                 case PGC_STRING:
5194                         return *((struct config_string *) record)->variable;
5195
5196                 case PGC_ENUM:
5197                         return config_enum_lookup_by_value((struct config_enum *) record,
5198                                                                                         *((struct config_enum *) record)->variable);
5199         }
5200         return NULL;
5201 }
5202
5203 /*
5204  * Get the RESET value associated with the given option.
5205  *
5206  * Note: this is not re-entrant, due to use of static result buffer;
5207  * not to mention that a string variable could have its reset_val changed.
5208  * Beware of assuming the result value is good for very long.
5209  */
5210 const char *
5211 GetConfigOptionResetString(const char *name)
5212 {
5213         struct config_generic *record;
5214         static char buffer[256];
5215
5216         record = find_option(name, false, ERROR);
5217         if (record == NULL)
5218                 ereport(ERROR,
5219                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5220                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5221         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
5222                 ereport(ERROR,
5223                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5224                                  errmsg("must be superuser to examine \"%s\"", name)));
5225
5226         switch (record->vartype)
5227         {
5228                 case PGC_BOOL:
5229                         return ((struct config_bool *) record)->reset_val ? "on" : "off";
5230
5231                 case PGC_INT:
5232                         snprintf(buffer, sizeof(buffer), "%d",
5233                                          ((struct config_int *) record)->reset_val);
5234                         return buffer;
5235
5236                 case PGC_REAL:
5237                         snprintf(buffer, sizeof(buffer), "%g",
5238                                          ((struct config_real *) record)->reset_val);
5239                         return buffer;
5240
5241                 case PGC_STRING:
5242                         return ((struct config_string *) record)->reset_val;
5243
5244                 case PGC_ENUM:
5245                         return config_enum_lookup_by_value((struct config_enum *) record,
5246                                                                                     ((struct config_enum *) record)->reset_val);
5247         }
5248         return NULL;
5249 }
5250
5251 /*
5252  * Detect whether the given configuration option can only be set by
5253  * a superuser.
5254  */
5255 bool
5256 IsSuperuserConfigOption(const char *name)
5257 {
5258         struct config_generic *record;
5259
5260         record = find_option(name, false, ERROR);
5261         /* On an unrecognized name, don't error, just return false. */
5262         if (record == NULL)
5263                 return false;
5264         return (record->context == PGC_SUSET);
5265 }
5266
5267
5268 /*
5269  * GUC_complaint_elevel
5270  *              Get the ereport error level to use in an assign_hook's error report.
5271  *
5272  * This should be used by assign hooks that want to emit a custom error
5273  * report (in addition to the generic "invalid value for option FOO" that
5274  * guc.c will provide).  Note that the result might be ERROR or a lower
5275  * level, so the caller must be prepared for control to return from ereport,
5276  * or not.  If control does return, return false/NULL from the hook function.
5277  *
5278  * At some point it'd be nice to replace this with a mechanism that allows
5279  * the custom message to become the DETAIL line of guc.c's generic message.
5280  */
5281 int
5282 GUC_complaint_elevel(GucSource source)
5283 {
5284         int                     elevel;
5285
5286         if (source == PGC_S_FILE)
5287         {
5288                 /*
5289                  * To avoid cluttering the log, only the postmaster bleats loudly
5290                  * about problems with the config file.
5291                  */
5292                 elevel = IsUnderPostmaster ? DEBUG3 : LOG;
5293         }
5294         else if (source == PGC_S_OVERRIDE)
5295         {
5296                 /*
5297                  * If we're a postmaster child, this is probably "undo" during
5298                  * transaction abort, so we don't want to clutter the log.  There's
5299                  * a small chance of a real problem with an OVERRIDE setting,
5300                  * though, so suppressing the message entirely wouldn't be desirable.
5301                  */
5302                 elevel = IsUnderPostmaster ? DEBUG5 : LOG;
5303         }
5304         else if (source < PGC_S_INTERACTIVE)
5305                 elevel = LOG;
5306         else
5307                 elevel = ERROR;
5308
5309         return elevel;
5310 }
5311
5312
5313 /*
5314  * flatten_set_variable_args
5315  *              Given a parsenode List as emitted by the grammar for SET,
5316  *              convert to the flat string representation used by GUC.
5317  *
5318  * We need to be told the name of the variable the args are for, because
5319  * the flattening rules vary (ugh).
5320  *
5321  * The result is NULL if args is NIL (ie, SET ... TO DEFAULT), otherwise
5322  * a palloc'd string.
5323  */
5324 static char *
5325 flatten_set_variable_args(const char *name, List *args)
5326 {
5327         struct config_generic *record;
5328         int                     flags;
5329         StringInfoData buf;
5330         ListCell   *l;
5331
5332         /* Fast path if just DEFAULT */
5333         if (args == NIL)
5334                 return NULL;
5335
5336         /* Else get flags for the variable */
5337         record = find_option(name, true, ERROR);
5338         if (record == NULL)
5339                 ereport(ERROR,
5340                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5341                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5342
5343         flags = record->flags;
5344
5345         /* Complain if list input and non-list variable */
5346         if ((flags & GUC_LIST_INPUT) == 0 &&
5347                 list_length(args) != 1)
5348                 ereport(ERROR,
5349                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5350                                  errmsg("SET %s takes only one argument", name)));
5351
5352         initStringInfo(&buf);
5353
5354         /*
5355          * Each list member may be a plain A_Const node, or an A_Const within a
5356          * TypeCast; the latter case is supported only for ConstInterval
5357          * arguments (for SET TIME ZONE).
5358          */
5359         foreach(l, args)
5360         {
5361                 Node       *arg = (Node *) lfirst(l);
5362                 char       *val;
5363                 TypeName   *typename = NULL;
5364                 A_Const    *con;
5365
5366                 if (l != list_head(args))
5367                         appendStringInfo(&buf, ", ");
5368
5369                 if (IsA(arg, TypeCast))
5370                 {
5371                         TypeCast *tc = (TypeCast *) arg;
5372
5373                         arg = tc->arg;
5374                         typename = tc->typename;
5375                 }
5376
5377                 if (!IsA(arg, A_Const))
5378                         elog(ERROR, "unrecognized node type: %d", (int) nodeTag(arg));
5379                 con = (A_Const *) arg;
5380
5381                 switch (nodeTag(&con->val))
5382                 {
5383                         case T_Integer:
5384                                 appendStringInfo(&buf, "%ld", intVal(&con->val));
5385                                 break;
5386                         case T_Float:
5387                                 /* represented as a string, so just copy it */
5388                                 appendStringInfoString(&buf, strVal(&con->val));
5389                                 break;
5390                         case T_String:
5391                                 val = strVal(&con->val);
5392                                 if (typename != NULL)
5393                                 {
5394                                         /*
5395                                          * Must be a ConstInterval argument for TIME ZONE. Coerce
5396                                          * to interval and back to normalize the value and account
5397                                          * for any typmod.
5398                                          */
5399                                         Oid                     typoid;
5400                                         int32           typmod;
5401                                         Datum           interval;
5402                                         char       *intervalout;
5403
5404                                         typoid = typenameTypeId(NULL, typename, &typmod);
5405                                         Assert(typoid == INTERVALOID);
5406
5407                                         interval =
5408                                                 DirectFunctionCall3(interval_in,
5409                                                                                         CStringGetDatum(val),
5410                                                                                         ObjectIdGetDatum(InvalidOid),
5411                                                                                         Int32GetDatum(typmod));
5412
5413                                         intervalout =
5414                                                 DatumGetCString(DirectFunctionCall1(interval_out,
5415                                                                                                                         interval));
5416                                         appendStringInfo(&buf, "INTERVAL '%s'", intervalout);
5417                                 }
5418                                 else
5419                                 {
5420                                         /*
5421                                          * Plain string literal or identifier.  For quote mode,
5422                                          * quote it if it's not a vanilla identifier.
5423                                          */
5424                                         if (flags & GUC_LIST_QUOTE)
5425                                                 appendStringInfoString(&buf, quote_identifier(val));
5426                                         else
5427                                                 appendStringInfoString(&buf, val);
5428                                 }
5429                                 break;
5430                         default:
5431                                 elog(ERROR, "unrecognized node type: %d",
5432                                          (int) nodeTag(&con->val));
5433                                 break;
5434                 }
5435         }
5436
5437         return buf.data;
5438 }
5439
5440
5441 /*
5442  * SET command
5443  */
5444 void
5445 ExecSetVariableStmt(VariableSetStmt *stmt)
5446 {
5447         GucAction       action = stmt->is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET;
5448
5449         switch (stmt->kind)
5450         {
5451                 case VAR_SET_VALUE:
5452                 case VAR_SET_CURRENT:
5453                         set_config_option(stmt->name,
5454                                                           ExtractSetVariableArgs(stmt),
5455                                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5456                                                           PGC_S_SESSION,
5457                                                           action,
5458                                                           true);
5459                         break;
5460                 case VAR_SET_MULTI:
5461
5462                         /*
5463                          * Special case for special SQL syntax that effectively sets more
5464                          * than one variable per statement.
5465                          */
5466                         if (strcmp(stmt->name, "TRANSACTION") == 0)
5467                         {
5468                                 ListCell   *head;
5469
5470                                 foreach(head, stmt->args)
5471                                 {
5472                                         DefElem    *item = (DefElem *) lfirst(head);
5473
5474                                         if (strcmp(item->defname, "transaction_isolation") == 0)
5475                                                 SetPGVariable("transaction_isolation",
5476                                                                           list_make1(item->arg), stmt->is_local);
5477                                         else if (strcmp(item->defname, "transaction_read_only") == 0)
5478                                                 SetPGVariable("transaction_read_only",
5479                                                                           list_make1(item->arg), stmt->is_local);
5480                                         else
5481                                                 elog(ERROR, "unexpected SET TRANSACTION element: %s",
5482                                                          item->defname);
5483                                 }
5484                         }
5485                         else if (strcmp(stmt->name, "SESSION CHARACTERISTICS") == 0)
5486                         {
5487                                 ListCell   *head;
5488
5489                                 foreach(head, stmt->args)
5490                                 {
5491                                         DefElem    *item = (DefElem *) lfirst(head);
5492
5493                                         if (strcmp(item->defname, "transaction_isolation") == 0)
5494                                                 SetPGVariable("default_transaction_isolation",
5495                                                                           list_make1(item->arg), stmt->is_local);
5496                                         else if (strcmp(item->defname, "transaction_read_only") == 0)
5497                                                 SetPGVariable("default_transaction_read_only",
5498                                                                           list_make1(item->arg), stmt->is_local);
5499                                         else
5500                                                 elog(ERROR, "unexpected SET SESSION element: %s",
5501                                                          item->defname);
5502                                 }
5503                         }
5504                         else
5505                                 elog(ERROR, "unexpected SET MULTI element: %s",
5506                                          stmt->name);
5507                         break;
5508                 case VAR_SET_DEFAULT:
5509                 case VAR_RESET:
5510                         set_config_option(stmt->name,
5511                                                           NULL,
5512                                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5513                                                           PGC_S_SESSION,
5514                                                           action,
5515                                                           true);
5516                         break;
5517                 case VAR_RESET_ALL:
5518                         ResetAllOptions();
5519                         break;
5520         }
5521 }
5522
5523 /*
5524  * Get the value to assign for a VariableSetStmt, or NULL if it's RESET.
5525  * The result is palloc'd.
5526  *
5527  * This is exported for use by actions such as ALTER ROLE SET.
5528  */
5529 char *
5530 ExtractSetVariableArgs(VariableSetStmt *stmt)
5531 {
5532         switch (stmt->kind)
5533         {
5534                 case VAR_SET_VALUE:
5535                         return flatten_set_variable_args(stmt->name, stmt->args);
5536                 case VAR_SET_CURRENT:
5537                         return GetConfigOptionByName(stmt->name, NULL);
5538                 default:
5539                         return NULL;
5540         }
5541 }
5542
5543 /*
5544  * SetPGVariable - SET command exported as an easily-C-callable function.
5545  *
5546  * This provides access to SET TO value, as well as SET TO DEFAULT (expressed
5547  * by passing args == NIL), but not SET FROM CURRENT functionality.
5548  */
5549 void
5550 SetPGVariable(const char *name, List *args, bool is_local)
5551 {
5552         char       *argstring = flatten_set_variable_args(name, args);
5553
5554         /* Note SET DEFAULT (argstring == NULL) is equivalent to RESET */
5555         set_config_option(name,
5556                                           argstring,
5557                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5558                                           PGC_S_SESSION,
5559                                           is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET,
5560                                           true);
5561 }
5562
5563 /*
5564  * SET command wrapped as a SQL callable function.
5565  */
5566 Datum
5567 set_config_by_name(PG_FUNCTION_ARGS)
5568 {
5569         char       *name;
5570         char       *value;
5571         char       *new_value;
5572         bool            is_local;
5573
5574         if (PG_ARGISNULL(0))
5575                 ereport(ERROR,
5576                                 (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
5577                                  errmsg("SET requires parameter name")));
5578
5579         /* Get the GUC variable name */
5580         name = TextDatumGetCString(PG_GETARG_DATUM(0));
5581
5582         /* Get the desired value or set to NULL for a reset request */
5583         if (PG_ARGISNULL(1))
5584                 value = NULL;
5585         else
5586                 value = TextDatumGetCString(PG_GETARG_DATUM(1));
5587
5588         /*
5589          * Get the desired state of is_local. Default to false if provided value
5590          * is NULL
5591          */
5592         if (PG_ARGISNULL(2))
5593                 is_local = false;
5594         else
5595                 is_local = PG_GETARG_BOOL(2);
5596
5597         /* Note SET DEFAULT (argstring == NULL) is equivalent to RESET */
5598         set_config_option(name,
5599                                           value,
5600                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5601                                           PGC_S_SESSION,
5602                                           is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET,
5603                                           true);
5604
5605         /* get the new current value */
5606         new_value = GetConfigOptionByName(name, NULL);
5607
5608         /* Convert return string to text */
5609         PG_RETURN_TEXT_P(cstring_to_text(new_value));
5610 }
5611
5612
5613 /*
5614  * Common code for DefineCustomXXXVariable subroutines: allocate the
5615  * new variable's config struct and fill in generic fields.
5616  */
5617 static struct config_generic *
5618 init_custom_variable(const char *name,
5619                                          const char *short_desc,
5620                                          const char *long_desc,
5621                                          GucContext context,
5622                                          enum config_type type,
5623                                          size_t sz)
5624 {
5625         struct config_generic *gen;
5626
5627         gen = (struct config_generic *) guc_malloc(ERROR, sz);
5628         memset(gen, 0, sz);
5629
5630         gen->name = guc_strdup(ERROR, name);
5631         gen->context = context;
5632         gen->group = CUSTOM_OPTIONS;
5633         gen->short_desc = short_desc;
5634         gen->long_desc = long_desc;
5635         gen->vartype = type;
5636
5637         return gen;
5638 }
5639
5640 /*
5641  * Common code for DefineCustomXXXVariable subroutines: insert the new
5642  * variable into the GUC variable array, replacing any placeholder.
5643  */
5644 static void
5645 define_custom_variable(struct config_generic * variable)
5646 {
5647         const char *name = variable->name;
5648         const char **nameAddr = &name;
5649         const char *value;
5650         struct config_string *pHolder;
5651         struct config_generic **res;
5652
5653         res = (struct config_generic **) bsearch((void *) &nameAddr,
5654                                                                                          (void *) guc_variables,
5655                                                                                          num_guc_variables,
5656                                                                                          sizeof(struct config_generic *),
5657                                                                                          guc_var_compare);
5658         if (res == NULL)
5659         {
5660                 /* No placeholder to replace, so just add it */
5661                 add_guc_variable(variable, ERROR);
5662                 return;
5663         }
5664
5665         /*
5666          * This better be a placeholder
5667          */
5668         if (((*res)->flags & GUC_CUSTOM_PLACEHOLDER) == 0)
5669                 ereport(ERROR,
5670                                 (errcode(ERRCODE_INTERNAL_ERROR),
5671                                  errmsg("attempt to redefine parameter \"%s\"", name)));
5672
5673         Assert((*res)->vartype == PGC_STRING);
5674         pHolder = (struct config_string *) (*res);
5675
5676         /*
5677          * Replace the placeholder. We aren't changing the name, so no re-sorting
5678          * is necessary
5679          */
5680         *res = variable;
5681
5682         /*
5683          * Assign the string value stored in the placeholder to the real variable.
5684          *
5685          * XXX this is not really good enough --- it should be a nontransactional
5686          * assignment, since we don't want it to roll back if the current xact
5687          * fails later.
5688          */
5689         value = *pHolder->variable;
5690
5691         if (value)
5692                 set_config_option(name, value,
5693                                                   pHolder->gen.context, pHolder->gen.source,
5694                                                   GUC_ACTION_SET, true);
5695
5696         /*
5697          * Free up as much as we conveniently can of the placeholder structure
5698          * (this neglects any stack items...)
5699          */
5700         set_string_field(pHolder, pHolder->variable, NULL);
5701         set_string_field(pHolder, &pHolder->reset_val, NULL);
5702
5703         free(pHolder);
5704 }
5705
5706 void
5707 DefineCustomBoolVariable(const char *name,
5708                                                  const char *short_desc,
5709                                                  const char *long_desc,
5710                                                  bool *valueAddr,
5711                                                  GucContext context,
5712                                                  GucBoolAssignHook assign_hook,
5713                                                  GucShowHook show_hook)
5714 {
5715         struct config_bool *var;
5716
5717         var = (struct config_bool *)
5718                 init_custom_variable(name, short_desc, long_desc, context,
5719                                                          PGC_BOOL, sizeof(struct config_bool));
5720         var->variable = valueAddr;
5721         var->boot_val = *valueAddr;
5722         var->reset_val = *valueAddr;
5723         var->assign_hook = assign_hook;
5724         var->show_hook = show_hook;
5725         define_custom_variable(&var->gen);
5726 }
5727
5728 void
5729 DefineCustomIntVariable(const char *name,
5730                                                 const char *short_desc,
5731                                                 const char *long_desc,
5732                                                 int *valueAddr,
5733                                                 int minValue,
5734                                                 int maxValue,
5735                                                 GucContext context,
5736                                                 GucIntAssignHook assign_hook,
5737                                                 GucShowHook show_hook)
5738 {
5739         struct config_int *var;
5740
5741         var = (struct config_int *)
5742                 init_custom_variable(name, short_desc, long_desc, context,
5743                                                          PGC_INT, sizeof(struct config_int));
5744         var->variable = valueAddr;
5745         var->boot_val = *valueAddr;
5746         var->reset_val = *valueAddr;
5747         var->min = minValue;
5748         var->max = maxValue;
5749         var->assign_hook = assign_hook;
5750         var->show_hook = show_hook;
5751         define_custom_variable(&var->gen);
5752 }
5753
5754 void
5755 DefineCustomRealVariable(const char *name,
5756                                                  const char *short_desc,
5757                                                  const char *long_desc,
5758                                                  double *valueAddr,
5759                                                  double minValue,
5760                                                  double maxValue,
5761                                                  GucContext context,
5762                                                  GucRealAssignHook assign_hook,
5763                                                  GucShowHook show_hook)
5764 {
5765         struct config_real *var;
5766
5767         var = (struct config_real *)
5768                 init_custom_variable(name, short_desc, long_desc, context,
5769                                                          PGC_REAL, sizeof(struct config_real));
5770         var->variable = valueAddr;
5771         var->boot_val = *valueAddr;
5772         var->reset_val = *valueAddr;
5773         var->min = minValue;
5774         var->max = maxValue;
5775         var->assign_hook = assign_hook;
5776         var->show_hook = show_hook;
5777         define_custom_variable(&var->gen);
5778 }
5779
5780 void
5781 DefineCustomStringVariable(const char *name,
5782                                                    const char *short_desc,
5783                                                    const char *long_desc,
5784                                                    char **valueAddr,
5785                                                    GucContext context,
5786                                                    GucStringAssignHook assign_hook,
5787                                                    GucShowHook show_hook)
5788 {
5789         struct config_string *var;
5790
5791         var = (struct config_string *)
5792                 init_custom_variable(name, short_desc, long_desc, context,
5793                                                          PGC_STRING, sizeof(struct config_string));
5794         var->variable = valueAddr;
5795         var->boot_val = *valueAddr;
5796         /* we could probably do without strdup, but keep it like normal case */
5797         if (var->boot_val)
5798                 var->reset_val = guc_strdup(ERROR, var->boot_val);
5799         var->assign_hook = assign_hook;
5800         var->show_hook = show_hook;
5801         define_custom_variable(&var->gen);
5802 }
5803
5804 void
5805 DefineCustomEnumVariable(const char *name,
5806                                                  const char *short_desc,
5807                                                  const char *long_desc,
5808                                                  int *valueAddr,
5809                                                  const struct config_enum_entry *options,
5810                                                  GucContext context,
5811                                                  GucEnumAssignHook assign_hook,
5812                                                  GucShowHook show_hook)
5813 {
5814         struct config_enum *var;
5815
5816         var = (struct config_enum *)
5817                 init_custom_variable(name, short_desc, long_desc, context,
5818                                                          PGC_ENUM, sizeof(struct config_enum));
5819         var->variable = valueAddr;
5820         var->boot_val = *valueAddr;
5821         var->reset_val = *valueAddr;
5822         var->options = options;
5823         var->assign_hook = assign_hook;
5824         var->show_hook = show_hook;
5825         define_custom_variable(&var->gen);
5826 }
5827
5828 void
5829 EmitWarningsOnPlaceholders(const char *className)
5830 {
5831         struct config_generic **vars = guc_variables;
5832         struct config_generic **last = vars + num_guc_variables;
5833
5834         int                     nameLen = strlen(className);
5835
5836         while (vars < last)
5837         {
5838                 struct config_generic *var = *vars++;
5839
5840                 if ((var->flags & GUC_CUSTOM_PLACEHOLDER) != 0 &&
5841                         strncmp(className, var->name, nameLen) == 0 &&
5842                         var->name[nameLen] == GUC_QUALIFIER_SEPARATOR)
5843                 {
5844                         ereport(INFO,
5845                                         (errcode(ERRCODE_UNDEFINED_OBJECT),
5846                                          errmsg("unrecognized configuration parameter \"%s\"", var->name)));
5847                 }
5848         }
5849 }
5850
5851
5852 /*
5853  * SHOW command
5854  */
5855 void
5856 GetPGVariable(const char *name, DestReceiver *dest)
5857 {
5858         if (guc_name_compare(name, "all") == 0)
5859                 ShowAllGUCConfig(dest);
5860         else
5861                 ShowGUCConfigOption(name, dest);
5862 }
5863
5864 TupleDesc
5865 GetPGVariableResultDesc(const char *name)
5866 {
5867         TupleDesc       tupdesc;
5868
5869         if (guc_name_compare(name, "all") == 0)
5870         {
5871                 /* need a tuple descriptor representing three TEXT columns */
5872                 tupdesc = CreateTemplateTupleDesc(3, false);
5873                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
5874                                                    TEXTOID, -1, 0);
5875                 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
5876                                                    TEXTOID, -1, 0);
5877                 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "description",
5878                                                    TEXTOID, -1, 0);
5879
5880         }
5881         else
5882         {
5883                 const char *varname;
5884
5885                 /* Get the canonical spelling of name */
5886                 (void) GetConfigOptionByName(name, &varname);
5887
5888                 /* need a tuple descriptor representing a single TEXT column */
5889                 tupdesc = CreateTemplateTupleDesc(1, false);
5890                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, varname,
5891                                                    TEXTOID, -1, 0);
5892         }
5893         return tupdesc;
5894 }
5895
5896
5897 /*
5898  * SHOW command
5899  */
5900 static void
5901 ShowGUCConfigOption(const char *name, DestReceiver *dest)
5902 {
5903         TupOutputState *tstate;
5904         TupleDesc       tupdesc;
5905         const char *varname;
5906         char       *value;
5907
5908         /* Get the value and canonical spelling of name */
5909         value = GetConfigOptionByName(name, &varname);
5910
5911         /* need a tuple descriptor representing a single TEXT column */
5912         tupdesc = CreateTemplateTupleDesc(1, false);
5913         TupleDescInitEntry(tupdesc, (AttrNumber) 1, varname,
5914                                            TEXTOID, -1, 0);
5915
5916         /* prepare for projection of tuples */
5917         tstate = begin_tup_output_tupdesc(dest, tupdesc);
5918
5919         /* Send it */
5920         do_text_output_oneline(tstate, value);
5921
5922         end_tup_output(tstate);
5923 }
5924
5925 /*
5926  * SHOW ALL command
5927  */
5928 static void
5929 ShowAllGUCConfig(DestReceiver *dest)
5930 {
5931         bool            am_superuser = superuser();
5932         int                     i;
5933         TupOutputState *tstate;
5934         TupleDesc       tupdesc;
5935         char       *values[3];
5936
5937         /* need a tuple descriptor representing three TEXT columns */
5938         tupdesc = CreateTemplateTupleDesc(3, false);
5939         TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
5940                                            TEXTOID, -1, 0);
5941         TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
5942                                            TEXTOID, -1, 0);
5943         TupleDescInitEntry(tupdesc, (AttrNumber) 3, "description",
5944                                            TEXTOID, -1, 0);
5945
5946
5947         /* prepare for projection of tuples */
5948         tstate = begin_tup_output_tupdesc(dest, tupdesc);
5949
5950         for (i = 0; i < num_guc_variables; i++)
5951         {
5952                 struct config_generic *conf = guc_variables[i];
5953
5954                 if ((conf->flags & GUC_NO_SHOW_ALL) ||
5955                         ((conf->flags & GUC_SUPERUSER_ONLY) && !am_superuser))
5956                         continue;
5957
5958                 /* assign to the values array */
5959                 values[0] = (char *) conf->name;
5960                 values[1] = _ShowOption(conf, true);
5961                 values[2] = (char *) conf->short_desc;
5962
5963                 /* send it to dest */
5964                 do_tup_output(tstate, values);
5965
5966                 /* clean up */
5967                 if (values[1] != NULL)
5968                         pfree(values[1]);
5969         }
5970
5971         end_tup_output(tstate);
5972 }
5973
5974 /*
5975  * Return GUC variable value by name; optionally return canonical
5976  * form of name.  Return value is palloc'd.
5977  */
5978 char *
5979 GetConfigOptionByName(const char *name, const char **varname)
5980 {
5981         struct config_generic *record;
5982
5983         record = find_option(name, false, ERROR);
5984         if (record == NULL)
5985                 ereport(ERROR,
5986                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5987                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5988         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
5989                 ereport(ERROR,
5990                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5991                                  errmsg("must be superuser to examine \"%s\"", name)));
5992
5993         if (varname)
5994                 *varname = record->name;
5995
5996         return _ShowOption(record, true);
5997 }
5998
5999 /*
6000  * Return GUC variable value by variable number; optionally return canonical
6001  * form of name.  Return value is palloc'd.
6002  */
6003 void
6004 GetConfigOptionByNum(int varnum, const char **values, bool *noshow)
6005 {
6006         char            buffer[256];
6007         struct config_generic *conf;
6008
6009         /* check requested variable number valid */
6010         Assert((varnum >= 0) && (varnum < num_guc_variables));
6011
6012         conf = guc_variables[varnum];
6013
6014         if (noshow)
6015         {
6016                 if ((conf->flags & GUC_NO_SHOW_ALL) ||
6017                         ((conf->flags & GUC_SUPERUSER_ONLY) && !superuser()))
6018                         *noshow = true;
6019                 else
6020                         *noshow = false;
6021         }
6022
6023         /* first get the generic attributes */
6024
6025         /* name */
6026         values[0] = conf->name;
6027
6028         /* setting : use _ShowOption in order to avoid duplicating the logic */
6029         values[1] = _ShowOption(conf, false);
6030
6031         /* unit */
6032         if (conf->vartype == PGC_INT)
6033         {
6034                 static char buf[8];
6035
6036                 switch (conf->flags & (GUC_UNIT_MEMORY | GUC_UNIT_TIME))
6037                 {
6038                         case GUC_UNIT_KB:
6039                                 values[2] = "kB";
6040                                 break;
6041                         case GUC_UNIT_BLOCKS:
6042                                 snprintf(buf, sizeof(buf), "%dkB", BLCKSZ / 1024);
6043                                 values[2] = buf;
6044                                 break;
6045                         case GUC_UNIT_XBLOCKS:
6046                                 snprintf(buf, sizeof(buf), "%dkB", XLOG_BLCKSZ / 1024);
6047                                 values[2] = buf;
6048                                 break;
6049                         case GUC_UNIT_MS:
6050                                 values[2] = "ms";
6051                                 break;
6052                         case GUC_UNIT_S:
6053                                 values[2] = "s";
6054                                 break;
6055                         case GUC_UNIT_MIN:
6056                                 values[2] = "min";
6057                                 break;
6058                         default:
6059                                 values[2] = "";
6060                                 break;
6061                 }
6062         }
6063         else
6064                 values[2] = NULL;
6065
6066         /* group */
6067         values[3] = config_group_names[conf->group];
6068
6069         /* short_desc */
6070         values[4] = conf->short_desc;
6071
6072         /* extra_desc */
6073         values[5] = conf->long_desc;
6074
6075         /* context */
6076         values[6] = GucContext_Names[conf->context];
6077
6078         /* vartype */
6079         values[7] = config_type_names[conf->vartype];
6080
6081         /* source */
6082         values[8] = GucSource_Names[conf->source];
6083
6084         /* now get the type specifc attributes */
6085         switch (conf->vartype)
6086         {
6087                 case PGC_BOOL:
6088                         {
6089                                 /* min_val */
6090                                 values[9] = NULL;
6091
6092                                 /* max_val */
6093                                 values[10] = NULL;
6094
6095                                 /* enumvals */
6096                                 values[11] = NULL;
6097                         }
6098                         break;
6099
6100                 case PGC_INT:
6101                         {
6102                                 struct config_int *lconf = (struct config_int *) conf;
6103
6104                                 /* min_val */
6105                                 snprintf(buffer, sizeof(buffer), "%d", lconf->min);
6106                                 values[9] = pstrdup(buffer);
6107
6108                                 /* max_val */
6109                                 snprintf(buffer, sizeof(buffer), "%d", lconf->max);
6110                                 values[10] = pstrdup(buffer);
6111
6112                                 /* enumvals */
6113                                 values[11] = NULL;
6114                         }
6115                         break;
6116
6117                 case PGC_REAL:
6118                         {
6119                                 struct config_real *lconf = (struct config_real *) conf;
6120
6121                                 /* min_val */
6122                                 snprintf(buffer, sizeof(buffer), "%g", lconf->min);
6123                                 values[9] = pstrdup(buffer);
6124
6125                                 /* max_val */
6126                                 snprintf(buffer, sizeof(buffer), "%g", lconf->max);
6127                                 values[10] = pstrdup(buffer);
6128
6129                                 /* enumvals */
6130                                 values[11] = NULL;
6131                         }
6132                         break;
6133
6134                 case PGC_STRING:
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                         break;
6146
6147                 case PGC_ENUM:
6148                         {
6149                                 /* min_val */
6150                                 values[9] = NULL;
6151
6152                                 /* max_val */
6153                                 values[10] = NULL;
6154
6155                                 /* enumvals */
6156                                 values[11] = config_enum_get_options((struct config_enum *) conf, "", "");
6157                         }
6158                         break;
6159
6160                 default:
6161                         {
6162                                 /*
6163                                  * should never get here, but in case we do, set 'em to NULL
6164                                  */
6165
6166                                 /* min_val */
6167                                 values[9] = NULL;
6168
6169                                 /* max_val */
6170                                 values[10] = NULL;
6171
6172                                 /* enumvals */
6173                                 values[11] = NULL;
6174                         }
6175                         break;
6176         }
6177
6178         /* If the setting came from a config file, set the source location */
6179         if (conf->source == PGC_S_FILE)
6180         {
6181                 values[12] = conf->sourcefile;
6182                 snprintf(buffer, sizeof(buffer), "%d", conf->sourceline);
6183                 values[13] = pstrdup(buffer);
6184         }
6185         else
6186         {
6187                 values[12] = NULL;
6188                 values[13] = NULL;
6189         }
6190 }
6191
6192 /*
6193  * Return the total number of GUC variables
6194  */
6195 int
6196 GetNumConfigOptions(void)
6197 {
6198         return num_guc_variables;
6199 }
6200
6201 /*
6202  * show_config_by_name - equiv to SHOW X command but implemented as
6203  * a function.
6204  */
6205 Datum
6206 show_config_by_name(PG_FUNCTION_ARGS)
6207 {
6208         char       *varname;
6209         char       *varval;
6210
6211         /* Get the GUC variable name */
6212         varname = TextDatumGetCString(PG_GETARG_DATUM(0));
6213
6214         /* Get the value */
6215         varval = GetConfigOptionByName(varname, NULL);
6216
6217         /* Convert to text */
6218         PG_RETURN_TEXT_P(cstring_to_text(varval));
6219 }
6220
6221 /*
6222  * show_all_settings - equiv to SHOW ALL command but implemented as
6223  * a Table Function.
6224  */
6225 #define NUM_PG_SETTINGS_ATTS    14
6226
6227 Datum
6228 show_all_settings(PG_FUNCTION_ARGS)
6229 {
6230         FuncCallContext *funcctx;
6231         TupleDesc       tupdesc;
6232         int                     call_cntr;
6233         int                     max_calls;
6234         AttInMetadata *attinmeta;
6235         MemoryContext oldcontext;
6236
6237         /* stuff done only on the first call of the function */
6238         if (SRF_IS_FIRSTCALL())
6239         {
6240                 /* create a function context for cross-call persistence */
6241                 funcctx = SRF_FIRSTCALL_INIT();
6242
6243                 /*
6244                  * switch to memory context appropriate for multiple function calls
6245                  */
6246                 oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
6247
6248                 /*
6249                  * need a tuple descriptor representing NUM_PG_SETTINGS_ATTS columns
6250                  * of the appropriate types
6251                  */
6252                 tupdesc = CreateTemplateTupleDesc(NUM_PG_SETTINGS_ATTS, false);
6253                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
6254                                                    TEXTOID, -1, 0);
6255                 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
6256                                                    TEXTOID, -1, 0);
6257                 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "unit",
6258                                                    TEXTOID, -1, 0);
6259                 TupleDescInitEntry(tupdesc, (AttrNumber) 4, "category",
6260                                                    TEXTOID, -1, 0);
6261                 TupleDescInitEntry(tupdesc, (AttrNumber) 5, "short_desc",
6262                                                    TEXTOID, -1, 0);
6263                 TupleDescInitEntry(tupdesc, (AttrNumber) 6, "extra_desc",
6264                                                    TEXTOID, -1, 0);
6265                 TupleDescInitEntry(tupdesc, (AttrNumber) 7, "context",
6266                                                    TEXTOID, -1, 0);
6267                 TupleDescInitEntry(tupdesc, (AttrNumber) 8, "vartype",
6268                                                    TEXTOID, -1, 0);
6269                 TupleDescInitEntry(tupdesc, (AttrNumber) 9, "source",
6270                                                    TEXTOID, -1, 0);
6271                 TupleDescInitEntry(tupdesc, (AttrNumber) 10, "min_val",
6272                                                    TEXTOID, -1, 0);
6273                 TupleDescInitEntry(tupdesc, (AttrNumber) 11, "max_val",
6274                                                    TEXTOID, -1, 0);
6275                 TupleDescInitEntry(tupdesc, (AttrNumber) 12, "enumvals",
6276                                                    TEXTOID, -1, 0);
6277                 TupleDescInitEntry(tupdesc, (AttrNumber) 13, "sourcefile",
6278                                                    TEXTOID, -1, 0);
6279                 TupleDescInitEntry(tupdesc, (AttrNumber) 14, "sourceline",
6280                                                    INT4OID, -1, 0);
6281
6282                 /*
6283                  * Generate attribute metadata needed later to produce tuples from raw
6284                  * C strings
6285                  */
6286                 attinmeta = TupleDescGetAttInMetadata(tupdesc);
6287                 funcctx->attinmeta = attinmeta;
6288
6289                 /* total number of tuples to be returned */
6290                 funcctx->max_calls = GetNumConfigOptions();
6291
6292                 MemoryContextSwitchTo(oldcontext);
6293         }
6294
6295         /* stuff done on every call of the function */
6296         funcctx = SRF_PERCALL_SETUP();
6297
6298         call_cntr = funcctx->call_cntr;
6299         max_calls = funcctx->max_calls;
6300         attinmeta = funcctx->attinmeta;
6301
6302         if (call_cntr < max_calls)      /* do when there is more left to send */
6303         {
6304                 char       *values[NUM_PG_SETTINGS_ATTS];
6305                 bool            noshow;
6306                 HeapTuple       tuple;
6307                 Datum           result;
6308
6309                 /*
6310                  * Get the next visible GUC variable name and value
6311                  */
6312                 do
6313                 {
6314                         GetConfigOptionByNum(call_cntr, (const char **) values, &noshow);
6315                         if (noshow)
6316                         {
6317                                 /* bump the counter and get the next config setting */
6318                                 call_cntr = ++funcctx->call_cntr;
6319
6320                                 /* make sure we haven't gone too far now */
6321                                 if (call_cntr >= max_calls)
6322                                         SRF_RETURN_DONE(funcctx);
6323                         }
6324                 } while (noshow);
6325
6326                 /* build a tuple */
6327                 tuple = BuildTupleFromCStrings(attinmeta, values);
6328
6329                 /* make the tuple into a datum */
6330                 result = HeapTupleGetDatum(tuple);
6331
6332                 SRF_RETURN_NEXT(funcctx, result);
6333         }
6334         else
6335         {
6336                 /* do when there is no more left */
6337                 SRF_RETURN_DONE(funcctx);
6338         }
6339 }
6340
6341 static char *
6342 _ShowOption(struct config_generic * record, bool use_units)
6343 {
6344         char            buffer[256];
6345         const char *val;
6346
6347         switch (record->vartype)
6348         {
6349                 case PGC_BOOL:
6350                         {
6351                                 struct config_bool *conf = (struct config_bool *) record;
6352
6353                                 if (conf->show_hook)
6354                                         val = (*conf->show_hook) ();
6355                                 else
6356                                         val = *conf->variable ? "on" : "off";
6357                         }
6358                         break;
6359
6360                 case PGC_INT:
6361                         {
6362                                 struct config_int *conf = (struct config_int *) record;
6363
6364                                 if (conf->show_hook)
6365                                         val = (*conf->show_hook) ();
6366                                 else
6367                                 {
6368                                         /*
6369                                          * Use int64 arithmetic to avoid overflows in units
6370                                          * conversion.  If INT64_IS_BUSTED we might overflow
6371                                          * anyway and print bogus answers, but there are few
6372                                          * enough such machines that it doesn't seem worth
6373                                          * trying harder.
6374                                          */
6375                                         int64           result = *conf->variable;
6376                                         const char *unit;
6377
6378                                         if (use_units && result > 0 &&
6379                                                 (record->flags & GUC_UNIT_MEMORY))
6380                                         {
6381                                                 switch (record->flags & GUC_UNIT_MEMORY)
6382                                                 {
6383                                                         case GUC_UNIT_BLOCKS:
6384                                                                 result *= BLCKSZ / 1024;
6385                                                                 break;
6386                                                         case GUC_UNIT_XBLOCKS:
6387                                                                 result *= XLOG_BLCKSZ / 1024;
6388                                                                 break;
6389                                                 }
6390
6391                                                 if (result % KB_PER_GB == 0)
6392                                                 {
6393                                                         result /= KB_PER_GB;
6394                                                         unit = "GB";
6395                                                 }
6396                                                 else if (result % KB_PER_MB == 0)
6397                                                 {
6398                                                         result /= KB_PER_MB;
6399                                                         unit = "MB";
6400                                                 }
6401                                                 else
6402                                                 {
6403                                                         unit = "kB";
6404                                                 }
6405                                         }
6406                                         else if (use_units && result > 0 &&
6407                                                          (record->flags & GUC_UNIT_TIME))
6408                                         {
6409                                                 switch (record->flags & GUC_UNIT_TIME)
6410                                                 {
6411                                                         case GUC_UNIT_S:
6412                                                                 result *= MS_PER_S;
6413                                                                 break;
6414                                                         case GUC_UNIT_MIN:
6415                                                                 result *= MS_PER_MIN;
6416                                                                 break;
6417                                                 }
6418
6419                                                 if (result % MS_PER_D == 0)
6420                                                 {
6421                                                         result /= MS_PER_D;
6422                                                         unit = "d";
6423                                                 }
6424                                                 else if (result % MS_PER_H == 0)
6425                                                 {
6426                                                         result /= MS_PER_H;
6427                                                         unit = "h";
6428                                                 }
6429                                                 else if (result % MS_PER_MIN == 0)
6430                                                 {
6431                                                         result /= MS_PER_MIN;
6432                                                         unit = "min";
6433                                                 }
6434                                                 else if (result % MS_PER_S == 0)
6435                                                 {
6436                                                         result /= MS_PER_S;
6437                                                         unit = "s";
6438                                                 }
6439                                                 else
6440                                                 {
6441                                                         unit = "ms";
6442                                                 }
6443                                         }
6444                                         else
6445                                                 unit = "";
6446
6447                                         snprintf(buffer, sizeof(buffer), INT64_FORMAT "%s",
6448                                                          result, unit);
6449                                         val = buffer;
6450                                 }
6451                         }
6452                         break;
6453
6454                 case PGC_REAL:
6455                         {
6456                                 struct config_real *conf = (struct config_real *) record;
6457
6458                                 if (conf->show_hook)
6459                                         val = (*conf->show_hook) ();
6460                                 else
6461                                 {
6462                                         snprintf(buffer, sizeof(buffer), "%g",
6463                                                          *conf->variable);
6464                                         val = buffer;
6465                                 }
6466                         }
6467                         break;
6468
6469                 case PGC_STRING:
6470                         {
6471                                 struct config_string *conf = (struct config_string *) record;
6472
6473                                 if (conf->show_hook)
6474                                         val = (*conf->show_hook) ();
6475                                 else if (*conf->variable && **conf->variable)
6476                                         val = *conf->variable;
6477                                 else
6478                                         val = "";
6479                         }
6480                         break;
6481
6482                 case PGC_ENUM:
6483                         {
6484                                 struct config_enum *conf = (struct config_enum *) record;
6485
6486                                 if(conf->show_hook)
6487                                         val = (*conf->show_hook) ();
6488                                 else
6489                                         val = config_enum_lookup_by_value(conf, *conf->variable);
6490                         }
6491                         break;
6492
6493                 default:
6494                         /* just to keep compiler quiet */
6495                         val = "???";
6496                         break;
6497         }
6498
6499         return pstrdup(val);
6500 }
6501
6502
6503 /*
6504  * Attempt (badly) to detect if a proposed new GUC setting is the same
6505  * as the current value.
6506  *
6507  * XXX this does not really work because it doesn't account for the
6508  * effects of canonicalization of string values by assign_hooks.
6509  */
6510 static bool
6511 is_newvalue_equal(struct config_generic * record, const char *newvalue)
6512 {
6513         /* newvalue == NULL isn't supported */
6514         Assert(newvalue != NULL);
6515
6516         switch (record->vartype)
6517         {
6518                 case PGC_BOOL:
6519                         {
6520                                 struct config_bool *conf = (struct config_bool *) record;
6521                                 bool            newval;
6522
6523                                 return parse_bool(newvalue, &newval)
6524                                         && *conf->variable == newval;
6525                         }
6526                 case PGC_INT:
6527                         {
6528                                 struct config_int *conf = (struct config_int *) record;
6529                                 int                     newval;
6530
6531                                 return parse_int(newvalue, &newval, record->flags, NULL)
6532                                         && *conf->variable == newval;
6533                         }
6534                 case PGC_REAL:
6535                         {
6536                                 struct config_real *conf = (struct config_real *) record;
6537                                 double          newval;
6538
6539                                 return parse_real(newvalue, &newval)
6540                                         && *conf->variable == newval;
6541                         }
6542                 case PGC_STRING:
6543                         {
6544                                 struct config_string *conf = (struct config_string *) record;
6545
6546                                 return *conf->variable != NULL &&
6547                                         strcmp(*conf->variable, newvalue) == 0;
6548                         }
6549
6550                 case PGC_ENUM:
6551                         {
6552                                 struct config_enum *conf = (struct config_enum *) record;
6553                                 int                     newval;
6554
6555                                 return config_enum_lookup_by_name(conf, newvalue, &newval)
6556                                         && *conf->variable == newval;
6557                         }
6558         }
6559
6560         return false;
6561 }
6562
6563
6564 #ifdef EXEC_BACKEND
6565
6566 /*
6567  *      This routine dumps out all non-default GUC options into a binary
6568  *      file that is read by all exec'ed backends.  The format is:
6569  *
6570  *              variable name, string, null terminated
6571  *              variable value, string, null terminated
6572  *              variable source, integer
6573  */
6574 void
6575 write_nondefault_variables(GucContext context)
6576 {
6577         int                     i;
6578         int                     elevel;
6579         FILE       *fp;
6580
6581         Assert(context == PGC_POSTMASTER || context == PGC_SIGHUP);
6582
6583         elevel = (context == PGC_SIGHUP) ? LOG : ERROR;
6584
6585         /*
6586          * Open file
6587          */
6588         fp = AllocateFile(CONFIG_EXEC_PARAMS_NEW, "w");
6589         if (!fp)
6590         {
6591                 ereport(elevel,
6592                                 (errcode_for_file_access(),
6593                                  errmsg("could not write to file \"%s\": %m",
6594                                                 CONFIG_EXEC_PARAMS_NEW)));
6595                 return;
6596         }
6597
6598         for (i = 0; i < num_guc_variables; i++)
6599         {
6600                 struct config_generic *gconf = guc_variables[i];
6601
6602                 if (gconf->source != PGC_S_DEFAULT)
6603                 {
6604                         fprintf(fp, "%s", gconf->name);
6605                         fputc(0, fp);
6606
6607                         switch (gconf->vartype)
6608                         {
6609                                 case PGC_BOOL:
6610                                         {
6611                                                 struct config_bool *conf = (struct config_bool *) gconf;
6612
6613                                                 if (*conf->variable == 0)
6614                                                         fprintf(fp, "false");
6615                                                 else
6616                                                         fprintf(fp, "true");
6617                                         }
6618                                         break;
6619
6620                                 case PGC_INT:
6621                                         {
6622                                                 struct config_int *conf = (struct config_int *) gconf;
6623
6624                                                 fprintf(fp, "%d", *conf->variable);
6625                                         }
6626                                         break;
6627
6628                                 case PGC_REAL:
6629                                         {
6630                                                 struct config_real *conf = (struct config_real *) gconf;
6631
6632                                                 /* Could lose precision here? */
6633                                                 fprintf(fp, "%f", *conf->variable);
6634                                         }
6635                                         break;
6636
6637                                 case PGC_STRING:
6638                                         {
6639                                                 struct config_string *conf = (struct config_string *) gconf;
6640
6641                                                 fprintf(fp, "%s", *conf->variable);
6642                                         }
6643                                         break;
6644
6645                                 case PGC_ENUM:
6646                                         {
6647                                                 struct config_enum *conf = (struct config_enum *) gconf;
6648
6649                                                 fprintf(fp, "%s", config_enum_lookup_by_value(conf, *conf->variable));
6650                                         }
6651                                         break;
6652                         }
6653
6654                         fputc(0, fp);
6655
6656                         fwrite(&gconf->source, sizeof(gconf->source), 1, fp);
6657                 }
6658         }
6659
6660         if (FreeFile(fp))
6661         {
6662                 ereport(elevel,
6663                                 (errcode_for_file_access(),
6664                                  errmsg("could not write to file \"%s\": %m",
6665                                                 CONFIG_EXEC_PARAMS_NEW)));
6666                 return;
6667         }
6668
6669         /*
6670          * Put new file in place.  This could delay on Win32, but we don't hold
6671          * any exclusive locks.
6672          */
6673         rename(CONFIG_EXEC_PARAMS_NEW, CONFIG_EXEC_PARAMS);
6674 }
6675
6676
6677 /*
6678  *      Read string, including null byte from file
6679  *
6680  *      Return NULL on EOF and nothing read
6681  */
6682 static char *
6683 read_string_with_null(FILE *fp)
6684 {
6685         int                     i = 0,
6686                                 ch,
6687                                 maxlen = 256;
6688         char       *str = NULL;
6689
6690         do
6691         {
6692                 if ((ch = fgetc(fp)) == EOF)
6693                 {
6694                         if (i == 0)
6695                                 return NULL;
6696                         else
6697                                 elog(FATAL, "invalid format of exec config params file");
6698                 }
6699                 if (i == 0)
6700                         str = guc_malloc(FATAL, maxlen);
6701                 else if (i == maxlen)
6702                         str = guc_realloc(FATAL, str, maxlen *= 2);
6703                 str[i++] = ch;
6704         } while (ch != 0);
6705
6706         return str;
6707 }
6708
6709
6710 /*
6711  *      This routine loads a previous postmaster dump of its non-default
6712  *      settings.
6713  */
6714 void
6715 read_nondefault_variables(void)
6716 {
6717         FILE       *fp;
6718         char       *varname,
6719                            *varvalue;
6720         int                     varsource;
6721
6722         /*
6723          * Open file
6724          */
6725         fp = AllocateFile(CONFIG_EXEC_PARAMS, "r");
6726         if (!fp)
6727         {
6728                 /* File not found is fine */
6729                 if (errno != ENOENT)
6730                         ereport(FATAL,
6731                                         (errcode_for_file_access(),
6732                                          errmsg("could not read from file \"%s\": %m",
6733                                                         CONFIG_EXEC_PARAMS)));
6734                 return;
6735         }
6736
6737         for (;;)
6738         {
6739                 struct config_generic *record;
6740
6741                 if ((varname = read_string_with_null(fp)) == NULL)
6742                         break;
6743
6744                 if ((record = find_option(varname, true, FATAL)) == NULL)
6745                         elog(FATAL, "failed to locate variable %s in exec config params file", varname);
6746                 if ((varvalue = read_string_with_null(fp)) == NULL)
6747                         elog(FATAL, "invalid format of exec config params file");
6748                 if (fread(&varsource, sizeof(varsource), 1, fp) == 0)
6749                         elog(FATAL, "invalid format of exec config params file");
6750
6751                 (void) set_config_option(varname, varvalue, record->context,
6752                                                                  varsource, GUC_ACTION_SET, true);
6753                 free(varname);
6754                 free(varvalue);
6755         }
6756
6757         FreeFile(fp);
6758 }
6759 #endif   /* EXEC_BACKEND */
6760
6761
6762 /*
6763  * A little "long argument" simulation, although not quite GNU
6764  * compliant. Takes a string of the form "some-option=some value" and
6765  * returns name = "some_option" and value = "some value" in malloc'ed
6766  * storage. Note that '-' is converted to '_' in the option name. If
6767  * there is no '=' in the input string then value will be NULL.
6768  */
6769 void
6770 ParseLongOption(const char *string, char **name, char **value)
6771 {
6772         size_t          equal_pos;
6773         char       *cp;
6774
6775         AssertArg(string);
6776         AssertArg(name);
6777         AssertArg(value);
6778
6779         equal_pos = strcspn(string, "=");
6780
6781         if (string[equal_pos] == '=')
6782         {
6783                 *name = guc_malloc(FATAL, equal_pos + 1);
6784                 strlcpy(*name, string, equal_pos + 1);
6785
6786                 *value = guc_strdup(FATAL, &string[equal_pos + 1]);
6787         }
6788         else
6789         {
6790                 /* no equal sign in string */
6791                 *name = guc_strdup(FATAL, string);
6792                 *value = NULL;
6793         }
6794
6795         for (cp = *name; *cp; cp++)
6796                 if (*cp == '-')
6797                         *cp = '_';
6798 }
6799
6800
6801 /*
6802  * Handle options fetched from pg_database.datconfig, pg_authid.rolconfig,
6803  * pg_proc.proconfig, etc.      Caller must specify proper context/source/action.
6804  *
6805  * The array parameter must be an array of TEXT (it must not be NULL).
6806  */
6807 void
6808 ProcessGUCArray(ArrayType *array,
6809                                 GucContext context, GucSource source, GucAction action)
6810 {
6811         int                     i;
6812
6813         Assert(array != NULL);
6814         Assert(ARR_ELEMTYPE(array) == TEXTOID);
6815         Assert(ARR_NDIM(array) == 1);
6816         Assert(ARR_LBOUND(array)[0] == 1);
6817
6818         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
6819         {
6820                 Datum           d;
6821                 bool            isnull;
6822                 char       *s;
6823                 char       *name;
6824                 char       *value;
6825
6826                 d = array_ref(array, 1, &i,
6827                                           -1 /* varlenarray */ ,
6828                                           -1 /* TEXT's typlen */ ,
6829                                           false /* TEXT's typbyval */ ,
6830                                           'i' /* TEXT's typalign */ ,
6831                                           &isnull);
6832
6833                 if (isnull)
6834                         continue;
6835
6836                 s = TextDatumGetCString(d);
6837
6838                 ParseLongOption(s, &name, &value);
6839                 if (!value)
6840                 {
6841                         ereport(WARNING,
6842                                         (errcode(ERRCODE_SYNTAX_ERROR),
6843                                          errmsg("could not parse setting for parameter \"%s\"",
6844                                                         name)));
6845                         free(name);
6846                         continue;
6847                 }
6848
6849                 (void) set_config_option(name, value, context, source, action, true);
6850
6851                 free(name);
6852                 if (value)
6853                         free(value);
6854         }
6855 }
6856
6857
6858 /*
6859  * Add an entry to an option array.  The array parameter may be NULL
6860  * to indicate the current table entry is NULL.
6861  */
6862 ArrayType *
6863 GUCArrayAdd(ArrayType *array, const char *name, const char *value)
6864 {
6865         const char *varname;
6866         Datum           datum;
6867         char       *newval;
6868         ArrayType  *a;
6869
6870         Assert(name);
6871         Assert(value);
6872
6873         /* test if the option is valid */
6874         set_config_option(name, value,
6875                                           superuser() ? PGC_SUSET : PGC_USERSET,
6876                                           PGC_S_TEST, GUC_ACTION_SET, false);
6877
6878         /* convert name to canonical spelling, so we can use plain strcmp */
6879         (void) GetConfigOptionByName(name, &varname);
6880         name = varname;
6881
6882         newval = palloc(strlen(name) + 1 + strlen(value) + 1);
6883         sprintf(newval, "%s=%s", name, value);
6884         datum = CStringGetTextDatum(newval);
6885
6886         if (array)
6887         {
6888                 int                     index;
6889                 bool            isnull;
6890                 int                     i;
6891
6892                 Assert(ARR_ELEMTYPE(array) == TEXTOID);
6893                 Assert(ARR_NDIM(array) == 1);
6894                 Assert(ARR_LBOUND(array)[0] == 1);
6895
6896                 index = ARR_DIMS(array)[0] + 1; /* add after end */
6897
6898                 for (i = 1; i <= ARR_DIMS(array)[0]; i++)
6899                 {
6900                         Datum           d;
6901                         char       *current;
6902
6903                         d = array_ref(array, 1, &i,
6904                                                   -1 /* varlenarray */ ,
6905                                                   -1 /* TEXT's typlen */ ,
6906                                                   false /* TEXT's typbyval */ ,
6907                                                   'i' /* TEXT's typalign */ ,
6908                                                   &isnull);
6909                         if (isnull)
6910                                 continue;
6911                         current = TextDatumGetCString(d);
6912                         if (strncmp(current, newval, strlen(name) + 1) == 0)
6913                         {
6914                                 index = i;
6915                                 break;
6916                         }
6917                 }
6918
6919                 a = array_set(array, 1, &index,
6920                                           datum,
6921                                           false,
6922                                           -1 /* varlena array */ ,
6923                                           -1 /* TEXT's typlen */ ,
6924                                           false /* TEXT's typbyval */ ,
6925                                           'i' /* TEXT's typalign */ );
6926         }
6927         else
6928                 a = construct_array(&datum, 1,
6929                                                         TEXTOID,
6930                                                         -1, false, 'i');
6931
6932         return a;
6933 }
6934
6935
6936 /*
6937  * Delete an entry from an option array.  The array parameter may be NULL
6938  * to indicate the current table entry is NULL.  Also, if the return value
6939  * is NULL then a null should be stored.
6940  */
6941 ArrayType *
6942 GUCArrayDelete(ArrayType *array, const char *name)
6943 {
6944         const char *varname;
6945         ArrayType  *newarray;
6946         int                     i;
6947         int                     index;
6948
6949         Assert(name);
6950
6951         /* test if the option is valid */
6952         set_config_option(name, NULL,
6953                                           superuser() ? PGC_SUSET : PGC_USERSET,
6954                                           PGC_S_TEST, GUC_ACTION_SET, false);
6955
6956         /* convert name to canonical spelling, so we can use plain strcmp */
6957         (void) GetConfigOptionByName(name, &varname);
6958         name = varname;
6959
6960         /* if array is currently null, then surely nothing to delete */
6961         if (!array)
6962                 return NULL;
6963
6964         newarray = NULL;
6965         index = 1;
6966
6967         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
6968         {
6969                 Datum           d;
6970                 char       *val;
6971                 bool            isnull;
6972
6973                 d = array_ref(array, 1, &i,
6974                                           -1 /* varlenarray */ ,
6975                                           -1 /* TEXT's typlen */ ,
6976                                           false /* TEXT's typbyval */ ,
6977                                           'i' /* TEXT's typalign */ ,
6978                                           &isnull);
6979                 if (isnull)
6980                         continue;
6981                 val = TextDatumGetCString(d);
6982
6983                 /* ignore entry if it's what we want to delete */
6984                 if (strncmp(val, name, strlen(name)) == 0
6985                         && val[strlen(name)] == '=')
6986                         continue;
6987
6988                 /* else add it to the output array */
6989                 if (newarray)
6990                 {
6991                         newarray = array_set(newarray, 1, &index,
6992                                                                  d,
6993                                                                  false,
6994                                                                  -1 /* varlenarray */ ,
6995                                                                  -1 /* TEXT's typlen */ ,
6996                                                                  false /* TEXT's typbyval */ ,
6997                                                                  'i' /* TEXT's typalign */ );
6998                 }
6999                 else
7000                         newarray = construct_array(&d, 1,
7001                                                                            TEXTOID,
7002                                                                            -1, false, 'i');
7003
7004                 index++;
7005         }
7006
7007         return newarray;
7008 }
7009
7010
7011 /*
7012  * assign_hook and show_hook subroutines
7013  */
7014
7015 static const char *
7016 assign_log_destination(const char *value, bool doit, GucSource source)
7017 {
7018         char       *rawstring;
7019         List       *elemlist;
7020         ListCell   *l;
7021         int                     newlogdest = 0;
7022
7023         /* Need a modifiable copy of string */
7024         rawstring = pstrdup(value);
7025
7026         /* Parse string into list of identifiers */
7027         if (!SplitIdentifierString(rawstring, ',', &elemlist))
7028         {
7029                 /* syntax error in list */
7030                 pfree(rawstring);
7031                 list_free(elemlist);
7032                 ereport(GUC_complaint_elevel(source),
7033                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7034                         errmsg("invalid list syntax for parameter \"log_destination\"")));
7035                 return NULL;
7036         }
7037
7038         foreach(l, elemlist)
7039         {
7040                 char       *tok = (char *) lfirst(l);
7041
7042                 if (pg_strcasecmp(tok, "stderr") == 0)
7043                         newlogdest |= LOG_DESTINATION_STDERR;
7044                 else if (pg_strcasecmp(tok, "csvlog") == 0)
7045                         newlogdest |= LOG_DESTINATION_CSVLOG;
7046 #ifdef HAVE_SYSLOG
7047                 else if (pg_strcasecmp(tok, "syslog") == 0)
7048                         newlogdest |= LOG_DESTINATION_SYSLOG;
7049 #endif
7050 #ifdef WIN32
7051                 else if (pg_strcasecmp(tok, "eventlog") == 0)
7052                         newlogdest |= LOG_DESTINATION_EVENTLOG;
7053 #endif
7054                 else
7055                 {
7056                         ereport(GUC_complaint_elevel(source),
7057                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7058                                   errmsg("unrecognized \"log_destination\" key word: \"%s\"",
7059                                                  tok)));
7060                         pfree(rawstring);
7061                         list_free(elemlist);
7062                         return NULL;
7063                 }
7064         }
7065
7066         if (doit)
7067                 Log_destination = newlogdest;
7068
7069         pfree(rawstring);
7070         list_free(elemlist);
7071
7072         return value;
7073 }
7074
7075 #ifdef HAVE_SYSLOG
7076
7077 static bool
7078 assign_syslog_facility(int newval, bool doit, GucSource source)
7079 {
7080         if (doit)
7081                 set_syslog_parameters(syslog_ident_str ? syslog_ident_str : "postgres",
7082                                                           newval);
7083
7084         return true;
7085 }
7086
7087 static const char *
7088 assign_syslog_ident(const char *ident, bool doit, GucSource source)
7089 {
7090         if (doit)
7091                 set_syslog_parameters(ident, syslog_facility);
7092
7093         return ident;
7094 }
7095 #endif   /* HAVE_SYSLOG */
7096
7097
7098 static bool
7099 assign_session_replication_role(int newval, bool doit, GucSource source)
7100 {
7101         /*
7102          * Must flush the plan cache when changing replication role; but don't
7103          * flush unnecessarily.
7104          */
7105         if (doit && SessionReplicationRole != newval)
7106         {
7107                 ResetPlanCache();
7108         }
7109
7110         return true;
7111 }
7112
7113 static const char *
7114 show_num_temp_buffers(void)
7115 {
7116         /*
7117          * We show the GUC var until local buffers have been initialized, and
7118          * NLocBuffer afterwards.
7119          */
7120         static char nbuf[32];
7121
7122         sprintf(nbuf, "%d", NLocBuffer ? NLocBuffer : num_temp_buffers);
7123         return nbuf;
7124 }
7125
7126 static bool
7127 assign_phony_autocommit(bool newval, bool doit, GucSource source)
7128 {
7129         if (!newval)
7130         {
7131                 ereport(GUC_complaint_elevel(source),
7132                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
7133                                  errmsg("SET AUTOCOMMIT TO OFF is no longer supported")));
7134                 return false;
7135         }
7136         return true;
7137 }
7138
7139 static const char *
7140 assign_custom_variable_classes(const char *newval, bool doit, GucSource source)
7141 {
7142         /*
7143          * Check syntax. newval must be a comma separated list of identifiers.
7144          * Whitespace is allowed but removed from the result.
7145          */
7146         bool            hasSpaceAfterToken = false;
7147         const char *cp = newval;
7148         int                     symLen = 0;
7149         char            c;
7150         StringInfoData buf;
7151
7152         initStringInfo(&buf);
7153         while ((c = *cp++) != '\0')
7154         {
7155                 if (isspace((unsigned char) c))
7156                 {
7157                         if (symLen > 0)
7158                                 hasSpaceAfterToken = true;
7159                         continue;
7160                 }
7161
7162                 if (c == ',')
7163                 {
7164                         if (symLen > 0)         /* terminate identifier */
7165                         {
7166                                 appendStringInfoChar(&buf, ',');
7167                                 symLen = 0;
7168                         }
7169                         hasSpaceAfterToken = false;
7170                         continue;
7171                 }
7172
7173                 if (hasSpaceAfterToken || !isalnum((unsigned char) c))
7174                 {
7175                         /*
7176                          * Syntax error due to token following space after token or non
7177                          * alpha numeric character
7178                          */
7179                         pfree(buf.data);
7180                         return NULL;
7181                 }
7182                 appendStringInfoChar(&buf, c);
7183                 symLen++;
7184         }
7185
7186         /* Remove stray ',' at end */
7187         if (symLen == 0 && buf.len > 0)
7188                 buf.data[--buf.len] = '\0';
7189
7190         /* GUC wants the result malloc'd */
7191         newval = guc_strdup(LOG, buf.data);
7192
7193         pfree(buf.data);
7194         return newval;
7195 }
7196
7197 static bool
7198 assign_debug_assertions(bool newval, bool doit, GucSource source)
7199 {
7200 #ifndef USE_ASSERT_CHECKING
7201         if (newval)
7202         {
7203                 ereport(GUC_complaint_elevel(source),
7204                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7205                            errmsg("assertion checking is not supported by this build")));
7206                 return false;
7207         }
7208 #endif
7209         return true;
7210 }
7211
7212 static bool
7213 assign_ssl(bool newval, bool doit, GucSource source)
7214 {
7215 #ifndef USE_SSL
7216         if (newval)
7217         {
7218                 ereport(GUC_complaint_elevel(source),
7219                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7220                                  errmsg("SSL is not supported by this build")));
7221                 return false;
7222         }
7223 #endif
7224         return true;
7225 }
7226
7227 static bool
7228 assign_stage_log_stats(bool newval, bool doit, GucSource source)
7229 {
7230         if (newval && log_statement_stats)
7231         {
7232                 ereport(GUC_complaint_elevel(source),
7233                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7234                                  errmsg("cannot enable parameter when \"log_statement_stats\" is true")));
7235                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7236                 if (source != PGC_S_OVERRIDE)
7237                         return false;
7238         }
7239         return true;
7240 }
7241
7242 static bool
7243 assign_log_stats(bool newval, bool doit, GucSource source)
7244 {
7245         if (newval &&
7246                 (log_parser_stats || log_planner_stats || log_executor_stats))
7247         {
7248                 ereport(GUC_complaint_elevel(source),
7249                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7250                                  errmsg("cannot enable \"log_statement_stats\" when "
7251                                                 "\"log_parser_stats\", \"log_planner_stats\", "
7252                                                 "or \"log_executor_stats\" is true")));
7253                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7254                 if (source != PGC_S_OVERRIDE)
7255                         return false;
7256         }
7257         return true;
7258 }
7259
7260 static bool
7261 assign_transaction_read_only(bool newval, bool doit, GucSource source)
7262 {
7263         /* Can't go to r/w mode inside a r/o transaction */
7264         if (newval == false && XactReadOnly && IsSubTransaction())
7265         {
7266                 ereport(GUC_complaint_elevel(source),
7267                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7268                                  errmsg("cannot set transaction read-write mode inside a read-only transaction")));
7269                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7270                 if (source != PGC_S_OVERRIDE)
7271                         return false;
7272         }
7273         return true;
7274 }
7275
7276 static const char *
7277 assign_canonical_path(const char *newval, bool doit, GucSource source)
7278 {
7279         if (doit)
7280         {
7281                 char       *canon_val = guc_strdup(ERROR, newval);
7282
7283                 canonicalize_path(canon_val);
7284                 return canon_val;
7285         }
7286         else
7287                 return newval;
7288 }
7289
7290 static const char *
7291 assign_timezone_abbreviations(const char *newval, bool doit, GucSource source)
7292 {
7293         /*
7294          * The powerup value shown above for timezone_abbreviations is "UNKNOWN".
7295          * When we see this we just do nothing.  If this value isn't overridden
7296          * from the config file then pg_timezone_abbrev_initialize() will
7297          * eventually replace it with "Default".  This hack has two purposes: to
7298          * avoid wasting cycles loading values that might soon be overridden from
7299          * the config file, and to avoid trying to read the timezone abbrev files
7300          * during InitializeGUCOptions().  The latter doesn't work in an
7301          * EXEC_BACKEND subprocess because my_exec_path hasn't been set yet and so
7302          * we can't locate PGSHAREDIR.  (Essentially the same hack is used to
7303          * delay initializing TimeZone ... if we have any more, we should try to
7304          * clean up and centralize this mechanism ...)
7305          */
7306         if (strcmp(newval, "UNKNOWN") == 0)
7307         {
7308                 return newval;
7309         }
7310
7311         /* Loading abbrev file is expensive, so only do it when value changes */
7312         if (timezone_abbreviations_string == NULL ||
7313                 strcmp(timezone_abbreviations_string, newval) != 0)
7314         {
7315                 int                     elevel;
7316
7317                 /*
7318                  * If reading config file, only the postmaster should bleat loudly
7319                  * about problems.      Otherwise, it's just this one process doing it,
7320                  * and we use WARNING message level.
7321                  */
7322                 if (source == PGC_S_FILE)
7323                         elevel = IsUnderPostmaster ? DEBUG3 : LOG;
7324                 else
7325                         elevel = WARNING;
7326                 if (!load_tzoffsets(newval, doit, elevel))
7327                         return NULL;
7328         }
7329         return newval;
7330 }
7331
7332 /*
7333  * pg_timezone_abbrev_initialize --- set default value if not done already
7334  *
7335  * This is called after initial loading of postgresql.conf.  If no
7336  * timezone_abbreviations setting was found therein, select default.
7337  */
7338 void
7339 pg_timezone_abbrev_initialize(void)
7340 {
7341         if (strcmp(timezone_abbreviations_string, "UNKNOWN") == 0)
7342         {
7343                 SetConfigOption("timezone_abbreviations", "Default",
7344                                                 PGC_POSTMASTER, PGC_S_ARGV);
7345         }
7346 }
7347
7348 static const char *
7349 show_archive_command(void)
7350 {
7351         if (XLogArchiveMode)
7352                 return XLogArchiveCommand;
7353         else
7354                 return "(disabled)";
7355 }
7356
7357 static bool
7358 assign_tcp_keepalives_idle(int newval, bool doit, GucSource source)
7359 {
7360         if (doit)
7361                 return (pq_setkeepalivesidle(newval, MyProcPort) == STATUS_OK);
7362
7363         return true;
7364 }
7365
7366 static const char *
7367 show_tcp_keepalives_idle(void)
7368 {
7369         static char nbuf[16];
7370
7371         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesidle(MyProcPort));
7372         return nbuf;
7373 }
7374
7375 static bool
7376 assign_tcp_keepalives_interval(int newval, bool doit, GucSource source)
7377 {
7378         if (doit)
7379                 return (pq_setkeepalivesinterval(newval, MyProcPort) == STATUS_OK);
7380
7381         return true;
7382 }
7383
7384 static const char *
7385 show_tcp_keepalives_interval(void)
7386 {
7387         static char nbuf[16];
7388
7389         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesinterval(MyProcPort));
7390         return nbuf;
7391 }
7392
7393 static bool
7394 assign_tcp_keepalives_count(int newval, bool doit, GucSource source)
7395 {
7396         if (doit)
7397                 return (pq_setkeepalivescount(newval, MyProcPort) == STATUS_OK);
7398
7399         return true;
7400 }
7401
7402 static const char *
7403 show_tcp_keepalives_count(void)
7404 {
7405         static char nbuf[16];
7406
7407         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivescount(MyProcPort));
7408         return nbuf;
7409 }
7410
7411 static bool
7412 assign_maxconnections(int newval, bool doit, GucSource source)
7413 {
7414         if (newval + autovacuum_max_workers > INT_MAX / 4)
7415                 return false;
7416
7417         if (doit)
7418                 MaxBackends = newval + autovacuum_max_workers;
7419
7420         return true;
7421 }
7422
7423 static bool
7424 assign_autovacuum_max_workers(int newval, bool doit, GucSource source)
7425 {
7426         if (newval + MaxConnections > INT_MAX / 4)
7427                 return false;
7428
7429         if (doit)
7430                 MaxBackends = newval + MaxConnections;
7431
7432         return true;
7433 }
7434
7435 static const char *
7436 assign_pgstat_temp_directory(const char *newval, bool doit, GucSource source)
7437 {
7438         if (doit)
7439         {
7440                 if (pgstat_stat_tmpname)
7441                         free(pgstat_stat_tmpname);
7442                 if (pgstat_stat_filename)
7443                         free(pgstat_stat_filename);
7444
7445                 pgstat_stat_tmpname = guc_malloc(FATAL, strlen(newval) + 12);  /* /pgstat.tmp */
7446                 pgstat_stat_filename = guc_malloc(FATAL, strlen(newval) + 13); /* /pgstat.stat */
7447
7448                 sprintf(pgstat_stat_tmpname, "%s/pgstat.tmp", newval);
7449                 sprintf(pgstat_stat_filename, "%s/pgstat.stat", newval);
7450         }
7451
7452         return newval;
7453 }
7454
7455 #include "guc-file.c"