Support an optional asynchronous commit mode, in which we don't flush WAL

[postgresql] / src / backend / utils / misc / postgresql.conf.sample

# -----------------------------
# PostgreSQL configuration file
# -----------------------------
#
# This file consists of lines of the form:
#
#   name = value
#
# (The '=' is optional.)  White space may be used.  Comments are introduced
# with '#' anywhere on a line.  The complete list of option names and
# allowed values can be found in the PostgreSQL documentation.  The
# commented-out settings shown in this file represent the default values.
#
# Please note that re-commenting a setting is NOT sufficient to revert it
# to the default value, unless you restart the server.
#
# Any option can also be given as a command line switch to the server,
# e.g., 'postgres -c log_connections=on'.  Some options can be changed at
# run-time with the 'SET' SQL command.
#
# This file is read on server startup and when the server receives a
# SIGHUP.  If you edit the file on a running system, you have to SIGHUP the
# server for the changes to take effect, or use "pg_ctl reload". Some
# settings, which are marked below, require a server shutdown and restart
# to take effect.
#
# Memory units:  kB = kilobytes MB = megabytes GB = gigabytes
# Time units:    ms = milliseconds s = seconds min = minutes h = hours d = days


#---------------------------------------------------------------------------
# FILE LOCATIONS
#---------------------------------------------------------------------------

# The default values of these variables are driven from the -D command line
# switch 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 = '(none)'           # write an extra PID file
                                        # (change requires restart)


#---------------------------------------------------------------------------
# CONNECTIONS AND AUTHENTICATION
#---------------------------------------------------------------------------

# - Connection Settings -

#listen_addresses = 'localhost'         # what IP address(es) to listen on; 
                                        # comma-separated list of addresses;
                                        # defaults to 'localhost', '*' = all
                                        # (change requires restart)
#port = 5432                            # (change requires restart)
#max_connections = 100                  # (change requires restart)
# Note: increasing max_connections costs ~400 bytes of shared memory per 
# connection slot, plus lock space (see max_locks_per_transaction).  You
# might also need to raise shared_buffers to support more connections.
#superuser_reserved_connections = 3     # (change requires restart)
#unix_socket_directory = ''             # (change requires restart)
#unix_socket_group = ''                 # (change requires restart)
#unix_socket_permissions = 0777         # octal
                                        # (change requires restart)
#bonjour_name = ''                      # defaults to the computer name
                                        # (change requires restart)

# - Security & Authentication -

#authentication_timeout = 1min          # 1s-600s
#ssl = off                              # (change requires restart)
#ssl_ciphers = 'ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH'      # Allowed SSL ciphers
                                        # (change requires restart)
#password_encryption = on
#db_user_namespace = off

# Kerberos and GSSAPI
#krb_server_keyfile = ''                # (change requires restart)
#krb_srvname = 'postgres'               # (change requires restart, kerberos only)
#krb_server_hostname = ''               # empty string matches any keytab entry
                                        # (change requires restart, kerberos only)
#krb_caseins_users = off                # (change requires restart)

# - TCP Keepalives -
# 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


#---------------------------------------------------------------------------
# RESOURCE USAGE (except WAL)
#---------------------------------------------------------------------------

# - Memory -

#shared_buffers = 32MB                  # min 128kB or max_connections*16kB
                                        # (change requires restart)
#temp_buffers = 8MB                     # min 800kB
#max_prepared_transactions = 5          # can be 0 or more
                                        # (change requires restart)
# Note: increasing max_prepared_transactions costs ~600 bytes of shared memory
# per transaction slot, plus lock space (see max_locks_per_transaction).
#work_mem = 1MB                         # min 64kB
#maintenance_work_mem = 16MB            # min 1MB
#max_stack_depth = 2MB                  # min 100kB

# - Free Space Map -

#max_fsm_pages = 204800                 # min max_fsm_relations*16, 6 bytes each
                                        # (change requires restart)
#max_fsm_relations = 1000               # min 100, ~70 bytes each
                                        # (change requires restart)

# - Kernel Resource Usage -

#max_files_per_process = 1000           # min 25
                                        # (change requires restart)
#shared_preload_libraries = ''          # (change requires restart)

# - Cost-Based Vacuum Delay -

#vacuum_cost_delay = 0                  # 0-1000 milliseconds
#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                # 0-10000 credits

# - Background writer -

#bgwriter_delay = 200ms                 # 10-10000ms between rounds
#bgwriter_lru_percent = 1.0             # 0-100% of LRU buffers scanned/round
#bgwriter_lru_maxpages = 5              # 0-1000 buffers max written/round


#---------------------------------------------------------------------------
# WRITE AHEAD LOG
#---------------------------------------------------------------------------

# - Settings -

#fsync = on                             # turns forced synchronization on or off
#synchronous_commit = on                # immediate fsync at commit
#wal_sync_method = fsync                # the default is the first option 
                                        # supported by the operating system:
                                        #   open_datasync
                                        #   fdatasync
                                        #   fsync
                                        #   fsync_writethrough
                                        #   open_sync
#full_page_writes = on                  # recover from partial page writes
#wal_buffers = 64kB                     # min 32kB
                                        # (change requires restart)
#wal_writer_delay = 200ms               # range 1-10000, in milliseconds

#commit_delay = 0                       # range 0-100000, in microseconds
#commit_siblings = 5                    # range 1-1000

# - Checkpoints -

#checkpoint_segments = 3                # in logfile segments, min 1, 16MB each
#checkpoint_timeout = 5min              # range 30s-1h
#checkpoint_completion_target = 0.5     # checkpoint target duration, 0.0 - 1.0
#checkpoint_warning = 30s               # 0 is off

# - Archiving -

#archive_command = ''           # command to use to archive a logfile segment
#archive_timeout = 0            # force a logfile segment switch after this
                                # many seconds; 0 is off


#---------------------------------------------------------------------------
# QUERY TUNING
#---------------------------------------------------------------------------

# - Planner Method Configuration -

#enable_bitmapscan = on
#enable_hashagg = on
#enable_hashjoin = on
#enable_indexscan = on
#enable_mergejoin = on
#enable_nestloop = on
#enable_seqscan = on
#enable_sort = on
#enable_tidscan = 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
#effective_cache_size = 128MB

# - 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

# - Other Planner Options -

#default_statistics_target = 10         # range 1-1000
#constraint_exclusion = off
#from_collapse_limit = 8
#join_collapse_limit = 8                # 1 disables collapsing of explicit 
                                        # JOINs


#---------------------------------------------------------------------------
# ERROR REPORTING AND LOGGING
#---------------------------------------------------------------------------

# - Where to Log -

#log_destination = 'stderr'             # Valid values are combinations of 
                                        # stderr, syslog and eventlog, 
                                        # depending on platform.

# This is used when logging to stderr:
#redirect_stderr = off                  # Enable capturing of stderr into log 
                                        # files
                                        # (change requires restart)

# These are only used if redirect_stderr is on:
#log_directory = 'pg_log'               # Directory where log files are written
                                        # Can be absolute or relative to PGDATA
#log_filename = 'postgresql-%Y-%m-%d_%H%M%S.log' # Log file name pattern.
                                        # Can include strftime() escapes
#log_truncate_on_rotation = off # If on, any existing log file of 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 to 
                                        # disable.
#log_rotation_size = 10MB               # Automatic rotation of logfiles will 
                                        # happen after that much log
                                        # output.  0 to disable.

# These are relevant when logging to syslog:
#syslog_facility = 'LOCAL0'
#syslog_ident = 'postgres'


# - When to Log -

#client_min_messages = notice           # Values in order of decreasing detail:
                                        #   debug5
                                        #   debug4
                                        #   debug3
                                        #   debug2
                                        #   debug1
                                        #   log
                                        #   notice
                                        #   warning
                                        #   error

#log_min_messages = notice              # Values in order of decreasing detail:
                                        #   debug5
                                        #   debug4
                                        #   debug3
                                        #   debug2
                                        #   debug1
                                        #   info
                                        #   notice
                                        #   warning
                                        #   error
                                        #   log
                                        #   fatal
                                        #   panic

#log_error_verbosity = default          # terse, default, or verbose messages

#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 N msec.


#silent_mode = off                      # DO NOT USE without syslog or 
                                        # redirect_stderr
                                        # (change requires restart)

# - What to Log -

#debug_print_parse = off
#debug_print_rewritten = off
#debug_print_plan = off
#debug_pretty_print = off
#log_checkpoints = off
#log_connections = off
#log_disconnections = off
#log_duration = off
#log_hostname = off
#log_line_prefix = ''                   # Special values:
                                        #   %u = user name
                                        #   %d = database name
                                        #   %r = remote host and port
                                        #   %h = remote host
                                        #   %p = PID
                                        #   %t = timestamp (no milliseconds)
                                        #   %m = timestamp with milliseconds
                                        #   %i = command tag
                                        #   %c = session id
                                        #   %l = session line number
                                        #   %s = session start timestamp
                                        #   %x = transaction id
                                        #   %q = stop here in non-session 
                                        #        processes
                                        #   %% = '%'
                                        # e.g. '<%u%%%d> '
#log_lock_waits = off                   # Log lock waits >= deadlock_timeout
#log_statement = 'none'                 # none, ddl, mod, all
#log_temp_files = -1                    # Log temporary files equal or larger
                                        # than specified number of kilobytes.
                                        # -1 disables;  0 logs all temp files

#---------------------------------------------------------------------------
# RUNTIME STATISTICS
#---------------------------------------------------------------------------

# - Query/Index Statistics Collector -

#stats_command_string = on
#update_process_title = on

#stats_start_collector = on             # needed for block or row stats
                                        # (change requires restart)
#stats_block_level = off
#stats_row_level = on
#stats_reset_on_server_start = off      # (change requires restart)


# - Statistics Monitoring -

#log_parser_stats = off
#log_planner_stats = off
#log_executor_stats = off
#log_statement_stats = off


#---------------------------------------------------------------------------
# AUTOVACUUM PARAMETERS
#---------------------------------------------------------------------------

#autovacuum = on                        # enable autovacuum subprocess?
                                        # 'on' requires stats_start_collector
                                        # and stats_row_level to also be on
#autovacuum_max_workers = 3             # max # of autovacuum subprocesses
#autovacuum_naptime = 1min              # time between autovacuum runs
#log_autovacuum = -1                    # -1 is disabled, 0 logs all actions
                                        # and their durations, > 0 logs only
                                        # actions running at least N msec.
#autovacuum_vacuum_threshold = 50       # min # of tuple updates before
                                        # vacuum
#autovacuum_analyze_threshold = 50      # min # of tuple updates before 
                                        # analyze
#autovacuum_vacuum_scale_factor = 0.2   # fraction of rel size before 
                                        # vacuum
#autovacuum_analyze_scale_factor = 0.1  # fraction of rel size before 
                                        # analyze
#autovacuum_freeze_max_age = 200000000  # maximum XID age before forced vacuum
                                        # (change requires restart)
#autovacuum_vacuum_cost_delay = 20      # default vacuum cost delay for 
                                        # autovacuum, -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 -

#search_path = '"$user",public'         # schema names
#default_tablespace = ''                # a tablespace name, '' uses
                                        # the default
#temp_tablespaces = ''                  # a list of tablespace names,
                                        # '' uses only default tablespace
#check_function_bodies = on
#default_transaction_isolation = 'read committed'
#default_transaction_read_only = off
#statement_timeout = 0                  # 0 is disabled
#session_replication_role = "origin"
#vacuum_freeze_min_age = 100000000
#xmlbinary = 'base64'
#xmloption = 'content'

# - Locale and Formatting -

#datestyle = 'iso, mdy'
#timezone = unknown                     # actually, defaults to TZ 
                                        # environment setting
#timezone_abbreviations = 'Default'     # select the set of available timezone
                                        # abbreviations. Currently, there are
                                        #   Default
                                        #   Australia
                                        #   India
                                        # However you can also create your own
                                        # file in share/timezonesets/.
#extra_float_digits = 0                 # min -15, max 2
#client_encoding = sql_ascii            # actually, defaults to database
                                        # encoding

# These settings are initialized by initdb -- they might be changed
#lc_messages = 'C'                      # locale for system error message 
                                        # strings
#lc_monetary = 'C'                      # locale for monetary formatting
#lc_numeric = 'C'                       # locale for number formatting
#lc_time = 'C'                          # locale for time formatting

# - Other Defaults -

#explain_pretty_print = on
#dynamic_library_path = '$libdir'
#local_preload_libraries = ''


#---------------------------------------------------------------------------
# LOCK MANAGEMENT
#---------------------------------------------------------------------------

#deadlock_timeout = 1s
#max_locks_per_transaction = 64         # min 10
                                        # (change requires restart)
# Note: each lock table slot uses ~270 bytes of shared memory, and there are
# max_locks_per_transaction * (max_connections + max_prepared_transactions)
# lock table slots.


#---------------------------------------------------------------------------
# VERSION/PLATFORM COMPATIBILITY
#---------------------------------------------------------------------------

# - Previous Postgres Versions -

#add_missing_from = off
#array_nulls = on
#backslash_quote = safe_encoding        # on, off, or safe_encoding
#default_with_oids = off
#escape_string_warning = on
#standard_conforming_strings = off
#regex_flavor = advanced                # advanced, extended, or basic
#sql_inheritance = on

# - Other Platforms & Clients -

#transform_null_equals = off


#---------------------------------------------------------------------------
# CUSTOMIZED OPTIONS
#---------------------------------------------------------------------------

#custom_variable_classes = ''           # list of custom variable class names