guc.c

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/*--------------------------------------------------------------------
 * guc.c
 *
 * Support for grand unified configuration scheme, including SET
 * command, configuration file, and command line options.
 * See src/backend/utils/misc/README for more information.
 *
 *
 * Copyright (c) 2000-2003, PostgreSQL Global Development Group
 * Written by Peter Eisentraut <[e-mail]>.
 *
 * IDENTIFICATION
 *	  $Header: /cvsroot/pgsql/src/backend/utils/misc/guc.c,v 1.164.2.3 2004/08/11 21:10:52 tgl Exp $
 *
 *--------------------------------------------------------------------
 */
#include "postgres.h"

#include <errno.h>
#include <float.h>
#include <limits.h>
#include <unistd.h>

#include "utils/guc.h"
#include "utils/guc_tables.h"

#include "access/xlog.h"
#include "catalog/namespace.h"
#include "catalog/pg_type.h"
#include "commands/async.h"
#include "commands/variable.h"
#include "commands/vacuum.h"
#include "executor/executor.h"
#include "fmgr.h"
#include "funcapi.h"
#include "libpq/auth.h"
#include "libpq/pqcomm.h"
#include "libpq/pqformat.h"
#include "mb/pg_wchar.h"
#include "miscadmin.h"
#include "optimizer/cost.h"
#include "optimizer/geqo.h"
#include "optimizer/paths.h"
#include "optimizer/prep.h"
#include "parser/parse_expr.h"
#include "parser/parse_relation.h"
#include "storage/fd.h"
#include "storage/freespace.h"
#include "storage/lock.h"
#include "storage/proc.h"
#include "tcop/tcopprot.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "utils/datetime.h"
#include "utils/pg_locale.h"
#include "pgstat.h"


#ifndef PG_KRB_SRVTAB
#define PG_KRB_SRVTAB ""
#endif

#ifdef EXEC_BACKEND
#define CONFIG_EXEC_PARAMS "global/config_exec_params"
#endif

/* XXX these should appear in other modules' header files */
extern bool Log_connections;
extern bool check_function_bodies;
extern int	PreAuthDelay;
extern int	AuthenticationTimeout;
extern int	CheckPointTimeout;
extern int	CommitDelay;
extern int	CommitSiblings;
extern char *preload_libraries_string;

#ifdef HAVE_SYSLOG
extern char *Syslog_facility;
extern char *Syslog_ident;

static const char *assign_facility(const char *facility,
				bool doit, bool interactive);
#endif

static const char *assign_defaultxactisolevel(const char *newval,
						   bool doit, bool interactive);
static const char *assign_log_min_messages(const char *newval,
						bool doit, bool interactive);
static const char *assign_client_min_messages(const char *newval,
						   bool doit, bool interactive);
static const char *assign_min_error_statement(const char *newval, bool doit,
						   bool interactive);
static const char *assign_msglvl(int *var, const char *newval,
			  bool doit, bool interactive);
static const char *assign_log_error_verbosity(const char *newval, bool doit,
						   bool interactive);
static bool assign_phony_autocommit(bool newval, bool doit, bool interactive);


/*
 * Debugging options
 */
#ifdef USE_ASSERT_CHECKING
bool		assert_enabled = true;
#endif
bool		log_statement = false;
bool		log_duration = false;
bool		Debug_print_plan = false;
bool		Debug_print_parse = false;
bool		Debug_print_rewritten = false;
bool		Debug_pretty_print = false;
bool		Explain_pretty_print = true;

bool		log_parser_stats = false;
bool		log_planner_stats = false;
bool		log_executor_stats = false;
bool		log_statement_stats = false;		/* this is sort of all
												 * three above together */
bool		log_btree_build_stats = false;

bool		SQL_inheritance = true;

bool		Australian_timezones = false;

bool		Password_encryption = true;

int			log_min_error_statement = PANIC;
int			log_min_messages = NOTICE;
int			client_min_messages = NOTICE;

int			log_min_duration_statement = -1;


/*
 * These variables are all dummies that don't do anything, except in some
 * cases provide the value for SHOW to display.  The real state is elsewhere
 * and is kept in sync by assign_hooks.
 */
static char *client_min_messages_str;
static char *log_min_messages_str;
static char *log_error_verbosity_str;
static char *log_min_error_statement_str;
static bool phony_autocommit;
static bool session_auth_is_superuser;
static double phony_random_seed;
static char *client_encoding_string;
static char *datestyle_string;
static char *default_iso_level_string;
static char *locale_collate;
static char *locale_ctype;
static char *regex_flavor_string;
static char *server_encoding_string;
static char *server_version_string;
static char *timezone_string;
static char *XactIsoLevel_string;
/* should be static, but commands/variable.c needs to get at it */
char *session_authorization_string;


/* Macros for freeing malloc'd pointers only if appropriate to do so */
/* Some of these tests are probably redundant, but be safe ... */
#define SET_STRING_VARIABLE(rec, newval) \
	do { \
		if (*(rec)->variable && \
			*(rec)->variable != (rec)->reset_val && \
			*(rec)->variable != (rec)->session_val && \
			*(rec)->variable != (rec)->tentative_val) \
			free(*(rec)->variable); \
		*(rec)->variable = (newval); \
	} while (0)
#define SET_STRING_RESET_VAL(rec, newval) \
	do { \
		if ((rec)->reset_val && \
			(rec)->reset_val != *(rec)->variable && \
			(rec)->reset_val != (rec)->session_val && \
			(rec)->reset_val != (rec)->tentative_val) \
			free((rec)->reset_val); \
		(rec)->reset_val = (newval); \
	} while (0)
#define SET_STRING_SESSION_VAL(rec, newval) \
	do { \
		if ((rec)->session_val && \
			(rec)->session_val != *(rec)->variable && \
			(rec)->session_val != (rec)->reset_val && \
			(rec)->session_val != (rec)->tentative_val) \
			free((rec)->session_val); \
		(rec)->session_val = (newval); \
	} while (0)
#define SET_STRING_TENTATIVE_VAL(rec, newval) \
	do { \
		if ((rec)->tentative_val && \
			(rec)->tentative_val != *(rec)->variable && \
			(rec)->tentative_val != (rec)->reset_val && \
			(rec)->tentative_val != (rec)->session_val) \
			free((rec)->tentative_val); \
		(rec)->tentative_val = (newval); \
	} while (0)


/*
 * Displayable names for context types (enum GucContext)
 *
 * Note: these strings are deliberately not localized.
 */
const char *const GucContext_Names[] =
{
	 /* PGC_INTERNAL */ "internal",
	 /* PGC_POSTMASTER */ "postmaster",
	 /* PGC_SIGHUP */ "sighup",
	 /* PGC_BACKEND */ "backend",
	 /* PGC_SUSET */ "superuser",
	 /* PGC_USERLIMIT */ "userlimit",
	 /* PGC_USERSET */ "user"
};

/*
 * Displayable names for source types (enum GucSource)
 *
 * Note: these strings are deliberately not localized.
 */
const char *const GucSource_Names[] =
{
	 /* PGC_S_DEFAULT */ "default",
	 /* PGC_S_ENV_VAR */ "environment variable",
	 /* PGC_S_FILE */ "configuration file",
	 /* PGC_S_ARGV */ "command line",
	 /* PGC_S_UNPRIVILEGED */ "unprivileged",
	 /* PGC_S_DATABASE */ "database",
	 /* PGC_S_USER */ "user",
	 /* PGC_S_CLIENT */ "client",
	 /* PGC_S_OVERRIDE */ "override",
	 /* PGC_S_SESSION */ "session"
};

/*
 * Displayable names for the groupings defined in enum config_group
 */
const char *const config_group_names[] =
{
	/* UNGROUPED */
	gettext_noop("Ungrouped"),
	/* CONN_AUTH */
	gettext_noop("Connections and Authentication"),
	/* CONN_AUTH_SETTINGS */
	gettext_noop("Connections and Authentication / Connection Settings"),
	/* CONN_AUTH_SECURITY */
	gettext_noop("Connections and Authentication / Security and Authentication"),
	/* RESOURCES */
	gettext_noop("Resource Usage"),
	/* RESOURCES_MEM */
	gettext_noop("Resource Usage / Memory"),
	/* RESOURCES_FSM */
	gettext_noop("Resource Usage / Free Space Map"),
	/* RESOURCES_KERNEL */
	gettext_noop("Resource Usage / Kernel Resources"),
	/* WAL */
	gettext_noop("Write-Ahead Log"),
	/* WAL_SETTINGS */
	gettext_noop("Write-Ahead Log / Settings"),
	/* WAL_CHECKPOINTS */
	gettext_noop("Write-Ahead Log / Checkpoints"),
	/* QUERY_TUNING */
	gettext_noop("Query Tuning"),
	/* QUERY_TUNING_METHOD */
	gettext_noop("Query Tuning / Planner Method Enabling"),
	/* QUERY_TUNING_COST */
	gettext_noop("Query Tuning / Planner Cost Constants"),
	/* QUERY_TUNING_GEQO */
	gettext_noop("Query Tuning / Genetic Query Optimizer"),
	/* QUERY_TUNING_OTHER */
	gettext_noop("Query Tuning / Other Planner Options"),
	/* LOGGING */
	gettext_noop("Reporting and Logging"),
	/* LOGGING_SYSLOG */
	gettext_noop("Reporting and Logging / Syslog"),
	/* LOGGING_WHEN */
	gettext_noop("Reporting and Logging / When to Log"),
	/* LOGGING_WHAT */
	gettext_noop("Reporting and Logging / What to Log"),
	/* STATS */
	gettext_noop("Statistics"),
	/* STATS_MONITORING */
	gettext_noop("Statistics / Monitoring"),
	/* STATS_COLLECTOR */
	gettext_noop("Statistics / Query and Index Statistics Collector"),
	/* CLIENT_CONN */
	gettext_noop("Client Connection Defaults"),
	/* CLIENT_CONN_STATEMENT */
	gettext_noop("Client Connection Defaults / Statement Behavior"),
	/* CLIENT_CONN_LOCALE */
	gettext_noop("Client Connection Defaults / Locale and Formatting"),
	/* CLIENT_CONN_OTHER */
	gettext_noop("Client Connection Defaults / Other Defaults"),
	/* LOCK_MANAGEMENT */
	gettext_noop("Lock Management"),
	/* COMPAT_OPTIONS */
	gettext_noop("Version and Platform Compatibility"),
	/* COMPAT_OPTIONS_PREVIOUS */
	gettext_noop("Version and Platform Compatibility / Previous PostgreSQL Versions"),
	/* COMPAT_OPTIONS_CLIENT */
	gettext_noop("Version and Platform Compatibility / Other Platforms and Clients"),
	/* DEVELOPER_OPTIONS */
	gettext_noop("Developer Options"),
	/* help_config wants this array to be null-terminated */
	NULL
};

/*
 * Displayable names for GUC variable types (enum config_type)
 *
 * Note: these strings are deliberately not localized.
 */
const char *const config_type_names[] =
{
	 /* PGC_BOOL */ "bool",
	 /* PGC_INT */ "integer",
	 /* PGC_REAL */ "real",
	 /* PGC_STRING */ "string"
};


/*
 * Contents of GUC tables
 *
 * See src/backend/utils/misc/README for design notes.
 *
 * TO ADD AN OPTION:
 *
 * 1. Declare a global variable of type bool, int, double, or char*
 * and make use of it.
 *
 * 2. Decide at what times it's safe to set the option. See guc.h for
 * details.
 *
 * 3. Decide on a name, a default value, upper and lower bounds (if
 * applicable), etc.
 *
 * 4. Add a record below.
 *
 * 5. Add it to src/backend/utils/misc/postgresql.conf.sample.
 *
 * 6. Add it to src/bin/psql/tab-complete.c, if it's a USERSET option.
 *
 * 7. Don't forget to document the option.
 */


/******** option records follow ********/

static struct config_bool ConfigureNamesBool[] =
{
	{
		{"enable_seqscan", PGC_USERSET, QUERY_TUNING_METHOD,
			gettext_noop("Enables the planner's use of sequential-scan plans."),
			NULL
		},
		&enable_seqscan,
		true, NULL, NULL
	},
	{
		{"enable_indexscan", PGC_USERSET, QUERY_TUNING_METHOD,
			gettext_noop("Enables the planner's use of index-scan plans."),
			NULL
		},
		&enable_indexscan,
		true, NULL, NULL
	},
	{
		{"enable_tidscan", PGC_USERSET, QUERY_TUNING_METHOD,
			gettext_noop("Enables the planner's use of TID scan plans."),
			NULL
		},
		&enable_tidscan,
		true, NULL, NULL
	},
	{
		{"enable_sort", PGC_USERSET, QUERY_TUNING_METHOD,
			gettext_noop("Enables the planner's use of explicit sort steps."),
			NULL
		},
		&enable_sort,
		true, NULL, NULL
	},
	{
		{"enable_hashagg", PGC_USERSET, QUERY_TUNING_METHOD,
			gettext_noop("Enables the planner's use of hashed aggregation plans."),
			NULL
		},
		&enable_hashagg,
		true, NULL, NULL
	},
	{
		{"enable_nestloop", PGC_USERSET, QUERY_TUNING_METHOD,
			gettext_noop("Enables the planner's use of nested-loop join plans."),
			NULL
		},
		&enable_nestloop,
		true, NULL, NULL
	},
	{
		{"enable_mergejoin", PGC_USERSET, QUERY_TUNING_METHOD,
			gettext_noop("Enables the planner's use of merge join plans."),
			NULL
		},
		&enable_mergejoin,
		true, NULL, NULL
	},
	{
		{"enable_hashjoin", PGC_USERSET, QUERY_TUNING_METHOD,
			gettext_noop("Enables the planner's use of hash join plans."),
			NULL
		},
		&enable_hashjoin,
		true, NULL, NULL
	},
	{
		{"geqo", PGC_USERSET, QUERY_TUNING_GEQO,
			gettext_noop("Enables genetic query optimization."),
			gettext_noop("This algorithm attempts to do planning without "
						 "exhaustive searching.")
		},
		&enable_geqo,
		true, NULL, NULL
	},
	{
		/* Not for general use --- used by SET SESSION AUTHORIZATION */
		{"is_superuser", PGC_INTERNAL, UNGROUPED,
			gettext_noop("Shows whether the current user is a superuser."),
			NULL,
			GUC_REPORT | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
		},
		&session_auth_is_superuser,
		false, NULL, NULL
	},
	{
		{"tcpip_socket", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
			gettext_noop("Makes the server accept TCP/IP connections."),
			NULL
		},
		&NetServer,
		false, NULL, NULL
	},
	{
		{"ssl", PGC_POSTMASTER, CONN_AUTH_SECURITY,
			gettext_noop("Enables SSL connections."),
			NULL
		},
		&EnableSSL,
		false, NULL, NULL
	},
	{
		{"fsync", PGC_SIGHUP, WAL_SETTINGS,
			gettext_noop("Forces synchronization of updates to disk."),
			gettext_noop("The server will use the fsync() system call in several places to make "
						 "sure that updates are physically written to disk. This insures "
						 "that a database cluster will recover to a consistent state after "
						 "an operating system or hardware crash.")
		},
		&enableFsync,
		true, NULL, NULL
	},
	{
		{"zero_damaged_pages", PGC_SUSET, DEVELOPER_OPTIONS,
			gettext_noop("Continues processing past damaged page headers."),
			gettext_noop("Detection of a damaged page header normally causes PostgreSQL to "
			"report an error, aborting the current transaction. Setting "
						 "zero_damaged_pages to true causes the system to instead report a "
						 "warning, zero out the damaged page, and continue processing. This "
						 "behavior will destroy data, namely all the rows on the damaged page."),
			GUC_NOT_IN_SAMPLE
		},
		&zero_damaged_pages,
		false, NULL, NULL
	},
	{
		{"silent_mode", PGC_POSTMASTER, LOGGING_WHEN,
			gettext_noop("Runs the server silently."),
			gettext_noop("If this parameter is set, the server will automatically run in the "
			"background and any controlling terminals are dissociated.")
		},
		&SilentMode,
		false, NULL, NULL
	},
	{
		{"log_connections", PGC_BACKEND, LOGGING_WHAT,
			gettext_noop("Logs each successful connection."),
			NULL
		},
		&Log_connections,
		false, NULL, NULL
	},
	{
		{"log_timestamp", PGC_SIGHUP, LOGGING_WHAT,
			gettext_noop("Prefixes server log messages with a time stamp."),