guc.c

PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统

/*--------------------------------------------------------------------
 * 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) 2000-2005, PostgreSQL Global Development Group
 * Written by Peter Eisentraut <[e-mail]>.
 *
 * IDENTIFICATION
 *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.299.2.3 2006/05/21 20:11:02 tgl Exp $
 *
 *--------------------------------------------------------------------
 */
#include "postgres.h"

#include <ctype.h>
#include <float.h>
#include <limits.h>
#include <unistd.h>
#include <sys/stat.h>
#ifdef HAVE_SYSLOG
#include <syslog.h>
#endif

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

#include "access/twophase.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/gramparse.h"
#include "parser/parse_expr.h"
#include "parser/parse_relation.h"
#include "parser/scansup.h"
#include "postmaster/autovacuum.h"
#include "postmaster/bgwriter.h"
#include "postmaster/syslogger.h"
#include "postmaster/postmaster.h"
#include "storage/bufmgr.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/memutils.h"
#include "utils/pg_locale.h"
#include "pgstat.h"


#ifndef PG_KRB_SRVTAB
#define PG_KRB_SRVTAB ""
#endif
#ifndef PG_KRB_SRVNAM
#define PG_KRB_SRVNAM ""
#endif

#define CONFIG_FILENAME "postgresql.conf"
#define HBA_FILENAME	"pg_hba.conf"
#define IDENT_FILENAME	"pg_ident.conf"

#ifdef EXEC_BACKEND
#define CONFIG_EXEC_PARAMS "global/config_exec_params"
#define CONFIG_EXEC_PARAMS_NEW "global/config_exec_params.new"
#endif

/* upper limit for GUC variables measured in kilobytes of memory */
#if SIZEOF_SIZE_T > 4
#define MAX_KILOBYTES	INT_MAX
#else
#define MAX_KILOBYTES	(INT_MAX / 1024)
#endif

/* XXX these should appear in other modules' header files */
extern bool Log_disconnections;
extern DLLIMPORT bool check_function_bodies;
extern int	CommitDelay;
extern int	CommitSiblings;
extern char *default_tablespace;
extern bool fullPageWrites;

#ifdef TRACE_SORT
extern bool trace_sort;
#endif

static const char *assign_log_destination(const char *value,
					   bool doit, GucSource source);

#ifdef HAVE_SYSLOG
static int	syslog_facility = LOG_LOCAL0;

static const char *assign_syslog_facility(const char *facility,
					   bool doit, GucSource source);
static const char *assign_syslog_ident(const char *ident,
					bool doit, GucSource source);
#endif

static const char *assign_defaultxactisolevel(const char *newval, bool doit,
						   GucSource source);
static const char *assign_log_min_messages(const char *newval, bool doit,
						GucSource source);
static const char *assign_client_min_messages(const char *newval,
						   bool doit, GucSource source);
static const char *assign_min_error_statement(const char *newval, bool doit,
						   GucSource source);
static const char *assign_msglvl(int *var, const char *newval, bool doit,
			  GucSource source);
static const char *assign_log_error_verbosity(const char *newval, bool doit,
						   GucSource source);
static const char *assign_log_statement(const char *newval, bool doit,
					 GucSource source);
static const char *show_num_temp_buffers(void);
static bool assign_phony_autocommit(bool newval, bool doit, GucSource source);
static const char *assign_custom_variable_classes(const char *newval, bool doit,
							   GucSource source);
static bool assign_stage_log_stats(bool newval, bool doit, GucSource source);
static bool assign_log_stats(bool newval, bool doit, GucSource source);
static bool assign_transaction_read_only(bool newval, bool doit, GucSource source);
static const char *assign_canonical_path(const char *newval, bool doit, GucSource source);
static const char *assign_backslash_quote(const char *newval, bool doit, GucSource source);

static bool assign_tcp_keepalives_idle(int newval, bool doit, GucSource source);
static bool assign_tcp_keepalives_interval(int newval, bool doit, GucSource source);
static bool assign_tcp_keepalives_count(int newval, bool doit, GucSource source);
static const char *show_tcp_keepalives_idle(void);
static const char *show_tcp_keepalives_interval(void);
static const char *show_tcp_keepalives_count(void);

/*
 * GUC option variables that are exported from this module
 */
#ifdef USE_ASSERT_CHECKING
bool		assert_enabled = true;
#endif
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;

bool		default_with_oids = false;

int			log_min_error_statement = PANIC;
int			log_min_messages = NOTICE;
int			client_min_messages = NOTICE;
int			log_min_duration_statement = -1;

int			num_temp_buffers = 1000;

char	   *ConfigFileName;
char	   *HbaFileName;
char	   *IdentFileName;
char	   *external_pid_file;

int			tcp_keepalives_idle;
int			tcp_keepalives_interval;
int			tcp_keepalives_count;

/*
 * 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_statement_str;
static char *log_min_error_statement_str;
static char *log_destination_string;
static char *syslog_facility_str;
static char *syslog_ident_str;
static bool phony_autocommit;
static bool session_auth_is_superuser;
static double phony_random_seed;
static char *backslash_quote_string;
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;
static char *data_directory;
static char *custom_variable_classes;
static int	max_function_args;
static int	max_index_keys;
static int	max_identifier_length;
static int	block_size;
static bool integer_datetimes;
static bool standard_conforming_strings;

/* should be static, but commands/variable.c needs to get at these */
char	   *role_string;
char	   *session_authorization_string;


/*
 * 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_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_DATABASE */ "database",
	 /* PGC_S_USER */ "user",
	 /* PGC_S_CLIENT */ "client",
	 /* PGC_S_OVERRIDE */ "override",
	 /* PGC_S_INTERACTIVE */ "interactive",
	 /* PGC_S_TEST */ "test",
	 /* PGC_S_SESSION */ "session"
};

/*
 * Displayable names for the groupings defined in enum config_group
 */
const char *const config_group_names[] =
{
	/* UNGROUPED */
	gettext_noop("Ungrouped"),
	/* FILE_LOCATIONS */
	gettext_noop("File Locations"),
	/* 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 Configuration"),
	/* 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_WHERE */
	gettext_noop("Reporting and Logging / Where to Log"),
	/* 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"),
	/* AUTOVACUUM */
	gettext_noop("Auto Vacuum"),
	/* 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"),
	/* PRESET_OPTIONS */
	gettext_noop("Preset Options"),
	/* CUSTOM_OPTIONS */
	gettext_noop("Customized Options"),
	/* 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, if
 *	  appropriate
 *
 * 6. Add it to src/bin/psql/tab-complete.c, if it's a USERSET option.
 *
 * 7. Don't forget to document the option.
 *
 * 8. If it's a new GUC_LIST option you must edit pg_dumpall.c to ensure
 *	  it is not single quoted at dump time.
 */


/******** 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_bitmapscan", PGC_USERSET, QUERY_TUNING_METHOD,
			gettext_noop("Enables the planner's use of bitmap-scan plans."),
			NULL
		},
		&enable_bitmapscan,
		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
	},
	{
		{"constraint_exclusion", PGC_USERSET, QUERY_TUNING_OTHER,
			gettext_noop("Enables the planner to use constraints to optimize queries."),
			gettext_noop("Child table scans will be skipped if their "
					   "constraints guarantee that no rows match the query.")
		},
		&constraint_exclusion,
		false, 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 */