深度解析PostgreSQL配置文件

配置文件 pg_hba.conf 详解[postgres@localhost data]$ vi pg_hba.conf# TYPE  DATABASE        USER            ADDRESS                 METHOD# "local" is for Unix domain socket connections onlylocal   all             all                                     trust# IPv4 local connections:host    all             all             127.0.0.1/32            trusthost    all             all             0.0.0.0/0               md5# IPv6 local connections:host    all             all             ::1/128                 trust# Allow replication connections from localhost, by a user with the# replication privilege.local   replication     all                                     trusthost    replication     all             127.0.0.1/32            trusthost    replication     all             ::1/128                 trusthost    replication     all             0.0.0.0/0               md5# "local" is for Unix domain socket connections only 这一行表示通过本机 socket 通信的时候我们认为他是受信赖的，这里直接配置 TRUST，所以当我们直接在命令行上输入 psql 的时候直接会进入数据库中。例如[postgres@localhost data]$ psqlpsql (12.8)Type "help" for help.postgres=## IPv4 local connections:host    all             all             127.0.0.1/32            trust这一行是当我们通过 TCP/IP 的方式进行连接的时候，如果是本机自己则我们也认为他是受信赖的，所以也是不需要输入密码的。[postgres@localhost data]$ psql -h 127.0.0.1psql (12.8)Type "help" for help.postgres=## IPv4 local connections:host    all             all             0.0.0.0/0               md5这一行是通过 TCP/IP 进行连接的时候，但是是从别的服务器进行连接的时候我们需要其进行输入密码的验证，否则不允许其进行连接。例如我们在 141 服务器连接本机[postgres@localhost ~]$ /usr/local/pgsql-12.8/bin/psql -h 192.168.30.140 -U postgres

配置文件 postgresql.conf 详解[postgres@localhost data]$ vi postgresql.conflisten_addresses = '*'port = 5432max_connections = 4000authentication_timeout = 1minpassword_encryption = md5shared_buffers = 4GBhuge_pages = trytemp_buffers = 8MBwork_mem = 4MBmaintenance_work_mem = 2048MBautovacuum_work_mem = -1effective_io_concurrency = 100max_worker_processes = 8max_parallel_maintenance_workers = 2max_parallel_workers_per_gather = 2parallel_leader_participation = onmax_parallel_workers = 8wal_level = logicalfsync = onsynchronous_commit = offwal_sync_method = fsyncfull_page_writes = onwal_log_hints = oncheckpoint_timeout = 5minmax_wal_size = 1GBmin_wal_size = 80MBcheckpoint_completion_target = 0.5archive_mode = onarchive_command = 'cp %p /usr/local/pgsql-12.8/data/wal_archive/%f'archive_cleanup_command = '/usr/local/pgsql-12.8/bin/pg_archivecleanup /usr/local/pgsql-12.8/data/wal_archive/ %r'max_wal_senders = 10wal_keep_segments = 512effective_cache_size = 4GBlog_destination = 'stderr'logging_collector = onlog_directory = 'log'log_filename = 'postgresql-%Y-%m-%d_%H%M%S.log'log_checkpoints = onlog_line_prefix = '%m [%p] %x %d %r %a %u 'log_lock_waits = onlog_statement = 'mod'log_timezone = 'Asia/Shanghai'autovacuum = onstatement_timeout = 60000idle_in_transaction_session_timeout = 30000timezone = 'Asia/Shanghai'lc_messages = 'en_US.UTF-8'lc_monetary = 'en_US.UTF-8'lc_numeric = 'en_US.UTF-8'lc_time = 'en_US.UTF-8'max_locks_per_transaction = 64上面的这些参数是需要重点关注的。

下面这部分是整个配置文件的内容# -----------------------------# PostgreSQL configuration file# -----------------------------## This file consists of lines of the form:##   name = value## (The "=" is optional.)  Whitespace may be used.  Comments are introduced with# "#" anywhere on a line.  The complete list of parameter names and allowed# values can be found in the PostgreSQL documentation.## The commented-out settings shown in this file represent the default values.# Re-commenting a setting is NOT sufficient to revert it to the default value;# you need to reload the server.## This file is read on server startup and when the server receives a SIGHUP# signal.  If you edit the file on a running system, you have to SIGHUP the# server for the changes to take effect, run "pg_ctl reload", or execute# "SELECT pg_reload_conf()".  Some parameters, which are marked below,# require a server shutdown and restart to take effect.## Any parameter can also be given as a command-line option to the server, e.g.,# "postgres -c log_connections=on".  Some parameters can be changed at run time# with the "SET" SQL command.## Memory units:  B  = bytes            Time units:  us  = microseconds#                kB = kilobytes                     ms  = milliseconds#                MB = megabytes                     s   = seconds#                GB = gigabytes                     min = minutes#                TB = terabytes                     h   = hours#                                                   d   = days#------------------------------------------------------------------------------# FILE LOCATIONS#------------------------------------------------------------------------------# The default values of these variables are driven from the -D command-line# option or PGDATA environment variable, represented here as ConfigDir.# data_directory = 'ConfigDir'      # use data in another directory                    # (change requires restart)# hba_file = 'ConfigDir/pg_hba.conf'    # host-based authentication file                    # (change requires restart)# ident_file = 'ConfigDir/pg_ident.conf'    # ident configuration file                    # (change requires restart)# If external_pid_file is not explicitly set, no extra PID file is written.# external_pid_file = ''        # write an extra PID file                    # (change requires restart)#------------------------------------------------------------------------------# CONNECTIONS AND AUTHENTICATION#------------------------------------------------------------------------------# - Connection Settings -listen_addresses = '*'          # what IP address(es) to listen on;                    # comma-separated list of addresses;                    # defaults to 'localhost'; use '*' for all                    # (change requires restart)port = 5432             # (change requires restart)max_connections = 4000          # (change requires restart)# superuser_reserved_connections = 3    # (change requires restart)# unix_socket_directories = '/tmp'  # comma-separated list of directories                    # (change requires restart)# unix_socket_group = ''        # (change requires restart)# unix_socket_permissions = 0777    # begin with 0 to use octal notation                    # (change requires restart)# bonjour = off             # advertise server via Bonjour                    # (change requires restart)# bonjour_name = ''         # defaults to the computer name                    # (change requires restart)# - TCP settings -# see "man 7 tcp" for details# tcp_keepalives_idle = 0       # TCP_KEEPIDLE, in seconds;                    # 0 selects the system default# tcp_keepalives_interval = 0       # TCP_KEEPINTVL, in seconds;                    # 0 selects the system default# tcp_keepalives_count = 0      # TCP_KEEPCNT;                    # 0 selects the system default# tcp_user_timeout = 0          # TCP_USER_TIMEOUT, in milliseconds;                    # 0 selects the system default# - Authentication -authentication_timeout = 1min       # 1s-600spassword_encryption = md5       # md5 or scram-sha-256# db_user_namespace = off# GSSAPI using Kerberos# krb_server_keyfile = 'FILE:${sysconfdir}/krb5.keytab'# krb_caseins_users = off# - SSL -# ssl = off# ssl_ca_file = ''# ssl_cert_file = 'server.crt'# ssl_crl_file = ''# ssl_key_file = 'server.key'# ssl_ciphers = 'HIGH:MEDIUM:+3DES:!aNULL' # allowed SSL ciphers# ssl_prefer_server_ciphers = on# ssl_ecdh_curve = 'prime256v1'# ssl_min_protocol_version = 'TLSv1'# ssl_max_protocol_version = ''# ssl_dh_params_file = ''# ssl_passphrase_command = ''# ssl_passphrase_command_supports_reload = off#------------------------------------------------------------------------------# RESOURCE USAGE (except WAL)#------------------------------------------------------------------------------# - Memory -shared_buffers = 4GB            # min 128kB                    # (change requires restart)huge_pages = try            # on, off, or try                    # (change requires restart)temp_buffers = 8MB          # min 800kB# max_prepared_transactions = 0     # zero disables the feature                    # (change requires restart)# Caution: it is not advisable to set max_prepared_transactions nonzero unless# you actively intend to use prepared transactions.work_mem = 4MB              # min 64kBmaintenance_work_mem = 2048MB       # min 1MBautovacuum_work_mem = -1        # min 1MB, or -1 to use maintenance_work_mem# max_stack_depth = 2MB         # min 100kB# shared_memory_type = mmap     # the default is the first option                    # supported by the operating system:                    #   mmap                    #   sysv                    #   windows                    # (change requires restart)dynamic_shared_memory_type = posix  # the default is the first option                    # supported by the operating system:                    #   posix                    #   sysv                    #   windows                    #   mmap                    # (change requires restart)# - Disk -temp_file_limit = -1            # limits per-process temp file space                    # in kB, or -1 for no limit# - Kernel Resources -# max_files_per_process = 1000      # min 25                    # (change requires restart)# - Cost-Based Vacuum Delay -# vacuum_cost_delay = 0         # 0-100 milliseconds (0 disables)# vacuum_cost_page_hit = 1      # 0-10000 credits# vacuum_cost_page_miss = 10        # 0-10000 credits# vacuum_cost_page_dirty = 20       # 0-10000 credits# vacuum_cost_limit = 200       # 1-10000 credits# - Background Writer -# bgwriter_delay = 200ms        # 10-10000ms between rounds# bgwriter_lru_maxpages = 100       # max buffers written/round, 0 disables# bgwriter_lru_multiplier = 2.0     # 0-10.0 multiplier on buffers scanned/round# bgwriter_flush_after = 512kB      # measured in pages, 0 disables# - Asynchronous Behavior -effective_io_concurrency = 100      # 1-1000; 0 disables prefetchingmax_worker_processes = 8        # (change requires restart)max_parallel_maintenance_workers = 2    # taken from max_parallel_workersmax_parallel_workers_per_gather = 2 # taken from max_parallel_workersparallel_leader_participation = onmax_parallel_workers = 8        # maximum number of max_worker_processes that                    # can be used in parallel operations# old_snapshot_threshold = -1       # 1min-60d; -1 disables; 0 is immediate                    # (change requires restart)# backend_flush_after = 0       # measured in pages, 0 disables#------------------------------------------------------------------------------# WRITE-AHEAD LOG#------------------------------------------------------------------------------# - Settings -wal_level = logical         # minimal, replica, or logical                    # (change requires restart)fsync = on              # flush data to disk for crash safety                    # (turning this off can cause                    # unrecoverable data corruption)synchronous_commit = off        # synchronization level;                    # off, local, remote_write, remote_apply, or onwal_sync_method = fsync         # the default is the first option                    # supported by the operating system:                    #   open_datasync                    #   fdatasync (default on Linux and FreeBSD)                    #   fsync                    #   fsync_writethrough                    #   open_syncfull_page_writes = on           # recover from partial page writes# wal_compression = off         # enable compression of full-page writeswal_log_hints = on          # also do full page writes of non-critical updates                    # (change requires restart)# wal_init_zero = on            # zero-fill new WAL files# wal_recycle = on          # recycle WAL files# wal_buffers = -1          # min 32kB, -1 sets based on shared_buffers                    # (change requires restart)# wal_writer_delay = 200ms      # 1-10000 milliseconds# wal_writer_flush_after = 1MB      # measured in pages, 0 disables# commit_delay = 0          # range 0-100000, in microseconds# commit_siblings = 5           # range 1-1000# - Checkpoints -checkpoint_timeout = 5min       # range 30s-1dmax_wal_size = 1GBmin_wal_size = 80MBcheckpoint_completion_target = 0.5  # checkpoint target duration, 0.0 - 1.0# checkpoint_flush_after = 256kB    # measured in pages, 0 disables# checkpoint_warning = 30s      # 0 disables# - Archiving -archive_mode = on       # enables archiving; off, on, or always                # (change requires restart)archive_command = 'cp %p /usr/local/pgsql-12.8/data/wal_archive/%f'     # command to use to archive a logfile segment                # placeholders: %p = path of file to archive                #               %f = file name only                # e.g. 'test ! -f /mnt/server/archivedir/%f && cp %p /mnt/server/archivedir/%f'# archive_timeout = 0       # force a logfile segment switch after this                # number of seconds; 0 disables# - Archive Recovery -# These are only used in recovery mode.# restore_command = ''      # command to use to restore an archived logfile segment                # placeholders: %p = path of file to restore                #               %f = file name only                # e.g. 'cp /mnt/server/archivedir/%f %p'                # (change requires restart)archive_cleanup_command = '/usr/local/pgsql-12.8/bin/pg_archivecleanup /usr/local/pgsql-12.8/data/wal_archive/ %r'  # command to execute at every restartpoint# recovery_end_command = '' # command to execute at completion of recovery# - Recovery Target -# Set these only when performing a targeted recovery.# recovery_target = ''      # 'immediate' to end recovery as soon as a                                # consistent state is reached                # (change requires restart)# recovery_target_name = '' # the named restore point to which recovery will proceed                # (change requires restart)# recovery_target_time = '' # the time stamp up to which recovery will proceed                # (change requires restart)# recovery_target_xid = ''  # the transaction ID up to which recovery will proceed                # (change requires restart)# recovery_target_lsn = ''  # the WAL LSN up to which recovery will proceed                # (change requires restart)# recovery_target_inclusive = on # Specifies whether to stop:                # just after the specified recovery target (on)                # just before the recovery target (off)                # (change requires restart)# recovery_target_timeline = 'latest'   # 'current', 'latest', or timeline ID                # (change requires restart)# recovery_target_action = 'pause'  # 'pause', 'promote', 'shutdown'                # (change requires restart)#------------------------------------------------------------------------------# REPLICATION#------------------------------------------------------------------------------# - Sending Servers -# Set these on the master and on any standby that will send replication data.max_wal_senders = 10        # max number of walsender processes                # (change requires restart)wal_keep_segments = 512     # in logfile segments; 0 disables# wal_sender_timeout = 60s  # in milliseconds; 0 disables# max_replication_slots = 10    # max number of replication slots                # (change requires restart)# track_commit_timestamp = off  # collect timestamp of transaction commit                # (change requires restart)# - Master Server -# These settings are ignored on a standby server.# synchronous_standby_names = ''    # standby servers that provide sync rep                # method to choose sync standbys, number of sync standbys,                # and comma-separated list of application_name                # from standby(s); '*' = all# vacuum_defer_cleanup_age = 0  # number of xacts by which cleanup is delayed# - Standby Servers -# These settings are ignored on a master server.# primary_conninfo = ''         # connection string to sending server                    # (change requires restart)# primary_slot_name = ''            # replication slot on sending server                    # (change requires restart)# promote_trigger_file = ''     # file name whose presence ends recovery# hot_standby = on          # "off" disallows queries during recovery                    # (change requires restart)# max_standby_archive_delay = 30s   # max delay before canceling queries                    # when reading WAL from archive;                    # -1 allows indefinite delay# max_standby_streaming_delay = 30s # max delay before canceling queries                    # when reading streaming WAL;                    # -1 allows indefinite delay# wal_receiver_status_interval = 10s    # send replies at least this often                    # 0 disables# hot_standby_feedback = off        # send info from standby to prevent                    # query conflicts# wal_receiver_timeout = 60s        # time that receiver waits for                    # communication from master                    # in milliseconds; 0 disables# wal_retrieve_retry_interval = 5s  # time to wait before retrying to                    # retrieve WAL after a failed attempt# recovery_min_apply_delay = 0      # minimum delay for applying changes during recovery# - Subscribers -# These settings are ignored on a publisher.# max_logical_replication_workers = 4   # taken from max_worker_processes                    # (change requires restart)# max_sync_workers_per_subscription = 2 # taken from max_logical_replication_workers#------------------------------------------------------------------------------# QUERY TUNING#------------------------------------------------------------------------------# - Planner Method Configuration -# enable_bitmapscan = on# enable_hashagg = on# enable_hashjoin = on# enable_indexscan = on# enable_indexonlyscan = on# enable_material = on# enable_mergejoin = on# enable_nestloop = on# enable_parallel_append = on# enable_seqscan = on# enable_sort = on# enable_tidscan = on# enable_partitionwise_join = off# enable_partitionwise_aggregate = off# enable_parallel_hash = on# enable_partition_pruning = on# - Planner Cost Constants -# seq_page_cost = 1.0           # measured on an arbitrary scale# random_page_cost = 4.0        # same scale as above# cpu_tuple_cost = 0.01         # same scale as above# cpu_index_tuple_cost = 0.005      # same scale as above# cpu_operator_cost = 0.0025        # same scale as above# parallel_tuple_cost = 0.1     # same scale as above# parallel_setup_cost = 1000.0  # same scale as above# jit_above_cost = 100000       # perform JIT compilation if available                    # and query more expensive than this;                    # -1 disables# jit_inline_above_cost = 500000    # inline small functions if query is                    # more expensive than this; -1 disables# jit_optimize_above_cost = 500000  # use expensive JIT optimizations if                    # query is more expensive than this;                    # -1 disables# min_parallel_table_scan_size = 8MB# min_parallel_index_scan_size = 512kBeffective_cache_size = 4GB# - Genetic Query Optimizer -# geqo = on# geqo_threshold = 12# geqo_effort = 5           # range 1-10# geqo_pool_size = 0            # selects default based on effort# geqo_generations = 0          # selects default based on effort# geqo_selection_bias = 2.0     # range 1.5-2.0# geqo_seed = 0.0           # range 0.0-1.0# - Other Planner Options -# default_statistics_target = 100   # range 1-10000# constraint_exclusion = partition  # on, off, or partition# cursor_tuple_fraction = 0.1       # range 0.0-1.0# from_collapse_limit = 8# join_collapse_limit = 8       # 1 disables collapsing of explicit                    # JOIN clauses# force_parallel_mode = off# jit = on              # allow JIT compilation# plan_cache_mode = auto        # auto, force_generic_plan or                    # force_custom_plan#------------------------------------------------------------------------------# REPORTING AND LOGGING#------------------------------------------------------------------------------# - Where to Log -log_destination = 'stderr'      # Valid values are combinations of                    # stderr, csvlog, syslog, and eventlog,                    # depending on platform.  csvlog                    # requires logging_collector to be on.# This is used when logging to stderr:logging_collector = on          # Enable capturing of stderr and csvlog                    # into log files. Required to be on for                    # csvlogs.                    # (change requires restart)# These are only used if logging_collector is on:log_directory = 'log'           # directory where log files are written,                    # can be absolute or relative to PGDATAlog_filename = 'postgresql-%Y-%m-%d_%H%M%S.log' # log file name pattern,                    # can include strftime() escapes# log_file_mode = 0600          # creation mode for log files,                    # begin with 0 to use octal notation# log_truncate_on_rotation = off    # If on, an existing log file with the                    # same name as the new log file will be                    # truncated rather than appended to.                    # But such truncation only occurs on                    # time-driven rotation, not on restarts                    # or size-driven rotation.  Default is                    # off, meaning append to existing files                    # in all cases.# log_rotation_age = 1d         # Automatic rotation of logfiles will                    # happen after that time.  0 disables.# log_rotation_size = 10MB      # Automatic rotation of logfiles will                    # happen after that much log output.                    # 0 disables.# These are relevant when logging to syslog:# syslog_facility = 'LOCAL0'# syslog_ident = 'postgres'# syslog_sequence_numbers = on# syslog_split_messages = on# This is only relevant when logging to eventlog (win32):# (change requires restart)# event_source = 'PostgreSQL'# - When to Log -# log_min_messages = warning        # values in order of decreasing detail:                    #   debug5                    #   debug4                    #   debug3                    #   debug2                    #   debug1                    #   info                    #   notice                    #   warning                    #   error                    #   log                    #   fatal                    #   panic# log_min_error_statement = error   # values in order of decreasing detail:                    #   debug5                    #   debug4                    #   debug3                    #   debug2                    #   debug1                    #   info                    #   notice                    #   warning                    #   error                    #   log                    #   fatal                    #   panic (effectively off)# log_min_duration_statement = -1   # -1 is disabled, 0 logs all statements                    # and their durations, > 0 logs only                    # statements running at least this number                    # of milliseconds# log_transaction_sample_rate = 0.0 # Fraction of transactions whose statements                    # are logged regardless of their duration. 1.0 logs all                    # statements from all transactions, 0.0 never logs.# - What to Log -# debug_print_parse = off# debug_print_rewritten = off# debug_print_plan = off# debug_pretty_print = onlog_checkpoints = on# log_connections = off# log_disconnections = off# log_duration = off# log_error_verbosity = default     # terse, default, or verbose messages# log_hostname = offlog_line_prefix = '%m [%p] %x %d %r %a %u '     # special values:                    #   %a = application name                    #   %u = user name                    #   %d = database name                    #   %r = remote host and port                    #   %h = remote host                    #   %p = process ID                    #   %t = timestamp without milliseconds                    #   %m = timestamp with milliseconds                    #   %n = timestamp with milliseconds (as a Unix epoch)                    #   %i = command tag                    #   %e = SQL state                    #   %c = session ID                    #   %l = session line number                    #   %s = session start timestamp                    #   %v = virtual transaction ID                    #   %x = transaction ID (0 if none)                    #   %q = stop here in non-session                    #        processes                    #   %% = '%'                    # e.g. '<%u%%%d> 'log_lock_waits = on         # log lock waits >= deadlock_timeoutlog_statement = 'mod'           # none, ddl, mod, all# log_replication_commands = off# log_temp_files = -1           # log temporary files equal or larger                    # than the specified size in kilobytes;                    # -1 disables, 0 logs all temp fileslog_timezone = 'Asia/Shanghai'#------------------------------------------------------------------------------# PROCESS TITLE#------------------------------------------------------------------------------# cluster_name = ''         # added to process titles if nonempty                    # (change requires restart)# update_process_title = on#------------------------------------------------------------------------------# STATISTICS#------------------------------------------------------------------------------# - Query and Index Statistics Collector -# track_activities = on# track_counts = on# track_io_timing = off# track_functions = none        # none, pl, all# track_activity_query_size = 1024  # (change requires restart)# stats_temp_directory = 'pg_stat_tmp'# - Monitoring -# log_parser_stats = off# log_planner_stats = off# log_executor_stats = off# log_statement_stats = off#------------------------------------------------------------------------------# AUTOVACUUM#------------------------------------------------------------------------------autovacuum = on             # Enable autovacuum subprocess?  'on'                    # requires track_counts to also be on.# log_autovacuum_min_duration = -1  # -1 disables, 0 logs all actions and                    # their durations, > 0 logs only                    # actions running at least this number                    # of milliseconds.# autovacuum_max_workers = 3        # max number of autovacuum subprocesses                    # (change requires restart)# autovacuum_naptime = 1min     # time between autovacuum runs# autovacuum_vacuum_threshold = 50  # min number of row updates before                    # vacuum# autovacuum_analyze_threshold = 50 # min number of row updates before                    # analyze# autovacuum_vacuum_scale_factor = 0.2  # fraction of table size before vacuum# autovacuum_analyze_scale_factor = 0.1 # fraction of table size before analyze# autovacuum_freeze_max_age = 200000000 # maximum XID age before forced vacuum                    # (change requires restart)# autovacuum_multixact_freeze_max_age = 400000000   # maximum multixact age                    # before forced vacuum                    # (change requires restart)# autovacuum_vacuum_cost_delay = 2ms    # default vacuum cost delay for                    # autovacuum, in milliseconds;                    # -1 means use vacuum_cost_delay# autovacuum_vacuum_cost_limit = -1 # default vacuum cost limit for                    # autovacuum, -1 means use                    # vacuum_cost_limit#------------------------------------------------------------------------------# CLIENT CONNECTION DEFAULTS#------------------------------------------------------------------------------# - Statement Behavior -# client_min_messages = notice      # values in order of decreasing detail:                    #   debug5                    #   debug4                    #   debug3                    #   debug2                    #   debug1                    #   log                    #   notice                    #   warning                    #   error# search_path = '"$user", public'   # schema names# row_security = on# default_tablespace = ''       # a tablespace name, '' uses the default# temp_tablespaces = ''         # a list of tablespace names, '' uses                    # only default tablespace# default_table_access_method = 'heap'# check_function_bodies = on# default_transaction_isolation = 'read committed'# default_transaction_read_only = off# default_transaction_deferrable = off# session_replication_role = 'origin'statement_timeout = 60000       # in milliseconds, 0 is disabled# lock_timeout = 0          # in milliseconds, 0 is disabledidle_in_transaction_session_timeout = 30000 # in milliseconds, 0 is disabled# vacuum_freeze_min_age = 50000000# vacuum_freeze_table_age = 150000000# vacuum_multixact_freeze_min_age = 5000000# vacuum_multixact_freeze_table_age = 150000000# vacuum_cleanup_index_scale_factor = 0.1   # fraction of total number of tuples                        # before index cleanup, 0 always performs                        # index cleanup# bytea_output = 'hex'          # hex, escape# xmlbinary = 'base64'# xmloption = 'content'# gin_fuzzy_search_limit = 0# gin_pending_list_limit = 4MB# - Locale and Formatting -datestyle = 'iso, mdy'# intervalstyle = 'postgres'timezone = 'Asia/Shanghai'# timezone_abbreviations = 'Default'    # Select the set of available time zone                    # abbreviations.  Currently, there are                    #   Default                    #   Australia (historical usage)                    #   India                    # You can create your own file in                    # share/timezonesets/.# extra_float_digits = 1        # min -15, max 3; any value >0 actually                    # selects precise output mode# client_encoding = sql_ascii       # actually, defaults to database                    # encoding# These settings are initialized by initdb, but they can be changed.lc_messages = 'en_US.UTF-8'         # locale for system error message                    # stringslc_monetary = 'en_US.UTF-8'         # locale for monetary formattinglc_numeric = 'en_US.UTF-8'          # locale for number formattinglc_time = 'en_US.UTF-8'             # locale for time formatting# default configuration for text searchdefault_text_search_config = 'pg_catalog.english'# - Shared Library Preloading -# shared_preload_libraries = ''     # (change requires restart)# local_preload_libraries = ''# session_preload_libraries = ''# jit_provider = 'llvmjit'      # JIT library to use# - Other Defaults -# dynamic_library_path = '$libdir'#------------------------------------------------------------------------------# LOCK MANAGEMENT#------------------------------------------------------------------------------# deadlock_timeout = 1s# max_locks_per_transaction = 64    # min 10                    # (change requires restart)# max_pred_locks_per_transaction = 64   # min 10                    # (change requires restart)# max_pred_locks_per_relation = -2  # negative values mean                    # (max_pred_locks_per_transaction                    #  / -max_pred_locks_per_relation) - 1# max_pred_locks_per_page = 2           # min 0#------------------------------------------------------------------------------# VERSION AND PLATFORM COMPATIBILITY#------------------------------------------------------------------------------# - Previous PostgreSQL Versions -# array_nulls = on# backslash_quote = safe_encoding   # on, off, or safe_encoding# escape_string_warning = on# lo_compat_privileges = off# operator_precedence_warning = off# quote_all_identifiers = off# standard_conforming_strings = on# synchronize_seqscans = on# - Other Platforms and Clients -# transform_null_equals = off#------------------------------------------------------------------------------# ERROR HANDLING#------------------------------------------------------------------------------# exit_on_error = off           # terminate session on any error?restart_after_crash = off       # reinitialize after backend crash?# data_sync_retry = off         # retry or panic on failure to fsync                    # data?                    # (change requires restart)#------------------------------------------------------------------------------# CONFIG FILE INCLUDES#------------------------------------------------------------------------------# These options allow settings to be loaded from files other than the# default postgresql.conf.  Note that these are directives, not variable# assignments, so they can usefully be given more than once.# include_dir = '...'           # include files ending in '.conf' from                    # a directory, e.g., 'conf.d'# include_if_exists = '...'     # include file only if it exists# include = '...'           # include file#------------------------------------------------------------------------------# CUSTOMIZED OPTIONS#------------------------------------------------------------------------------# Add settings for extensions here