PostgreSQL
PostgreSQL is a relational database. It was designed as the successor to Ingress.
Contents
Installation
Most Linux and BSD distributions offer a postgresql package that contains the core server components.
Docker container images are also available for all supported versions. The image is available from DockerHub as docker.io/library/postgres (or simply postgres when using docker(1) specifically).
Setup
Before using postgres(1), the database cluster needs to be instantiated.
initdb
For most usecases, this is sufficient. See here for details and more advanced usage.
Configuration
# -----------------------------
# 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
data_directory = '/var/lib/postgresql/data' # use data in another directory
hba_file = '/var/lib/postgresql/data/pg_hba.conf' # host-based authentication file
ident_file = '/var/lib/postgresql/data/pg_ident.conf' # ident configuration file
# If external_pid_file is not explicitly set, no extra PID file is written.
#external_pid_file = '' # write an extra PID file
#------------------------------------------------------------------------------
# CONNECTIONS AND AUTHENTICATION
#------------------------------------------------------------------------------
# - Connection Settings -
listen_addresses = 'localhost' # comma-separated list of addresses; defaults to 'localhost'; use '*' for all
port = 5432
#max_connections = 100
#superuser_reserved_connections = 3
unix_socket_directories = '/run/postgresql' # comma-separated list of directories
#unix_socket_group = ''
#unix_socket_permissions = 0777 # begin with 0 to use octal notation
bonjour = off
#bonjour_name = '' # defaults to the computer name
# - TCP settings -
# see "man 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
client_connection_check_interval = 0 # time between checks for client disconnection while running queries; 0 for never
# - Authentication -
#authentication_timeout = 1min # 1s-600s
#password_encryption = scram-sha-256 # scram-sha-256 or md5
#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_crl_dir = ''
#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 = 'TLSv1.2'
#ssl_max_protocol_version = ''
#ssl_dh_params_file = ''
#ssl_passphrase_command = ''
#ssl_passphrase_command_supports_reload = off
#------------------------------------------------------------------------------
# RESOURCE USAGE (except WAL)
#------------------------------------------------------------------------------
# - Memory -
#shared_buffers = 32MB # min 128kB
#huge_pages = try # on, off, or try
#huge_page_size = 0 # zero for system default
#temp_buffers = 8MB # min 800kB
#max_prepared_transactions = 0 # zero disables the feature; it is not advisable to set nonzero unless you actively intend to use prepared transactions
#work_mem = 4MB # min 64kB
#hash_mem_multiplier = 1.0 # 1-1000.0 multiplier on hash table work_mem
#maintenance_work_mem = 64MB # min 1MB
#autovacuum_work_mem = -1 # min 1MB, or -1 to use maintenance_work_mem
#logical_decoding_work_mem = 64MB # min 64kB
#max_stack_depth = 2MB # min 100kB
#shared_memory_type = mmap # the default is the first option supported by the operating system: mmap, sysv, windows
#dynamic_shared_memory_type = posix # the default is the first option supported by the operating system: posix, sysv, windows, mmap
#min_dynamic_shared_memory = 0MB
# - Disk -
#temp_file_limit = -1 # limits per-process temp file space in kilobytes, or -1 for no limit
# - Kernel Resources -
#max_files_per_process = 1000 # min 64
# - 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 = 2 # 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 = 0 # measured in pages, 0 disables
# - Asynchronous Behavior -
#backend_flush_after = 0 # measured in pages, 0 disables
#effective_io_concurrency = 1 # 1-1000; 0 disables prefetching
#maintenance_io_concurrency = 10 # 1-1000; 0 disables prefetching
#max_worker_processes = 8 # (change requires restart)
#max_parallel_workers_per_gather = 2 # taken from max_parallel_workers
#max_parallel_maintenance_workers = 2 # taken from max_parallel_workers
#max_parallel_workers = 8 # maximum number of max_worker_processes that can be used in parallel operations
#parallel_leader_participation = on
#old_snapshot_threshold = -1 # 1min-60d; -1 disables; 0 is immediate
#------------------------------------------------------------------------------
# WRITE-AHEAD LOG
#------------------------------------------------------------------------------
# - Settings -
#wal_level = replica # minimal, replica, or logical
#fsync = on # flush data to disk for crash safety (turning this off can cause unrecoverable data corruption)
#synchronous_commit = on # synchronization level; off, local, remote_write, remote_apply, on
#wal_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_sync
#full_page_writes = on # recover from partial page writes
#wal_log_hints = off # also do full page writes of non-critical updates
#wal_compression = off # enable compression of full-page writes
#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
#wal_writer_delay = 200ms # 1-10000 milliseconds
#wal_writer_flush_after = 1MB # measured in pages, 0 disables
#wal_skip_threshold = 2MB
#commit_delay = 0 # range 0-100000, in microseconds
#commit_siblings = 5 # range 1-1000
# - Checkpoints -
#checkpoint_timeout = 5min # range 30s-1d
#checkpoint_completion_target = 0.9 # checkpoint target duration, 0.0 - 1.0
#checkpoint_flush_after = 0 # measured in pages, 0 disables
#checkpoint_warning = 30s # 0 disables
#max_wal_size = 1GB
#min_wal_size = 80MB
# - Archiving -
#archive_mode = off # enables archiving; off, on, or always
#Placeholders for archive_command and restore_command:
# %p = path of file to archive
# %f = file name only
#archive_command = '' # command to use to archive a logfile segment; placeholders: %p = path of file to archive, %f = file name only
#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
#archive_cleanup_command = '' # command to execute at every restartpoint; see placeholders on line 198
#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
#recovery_target_name = '' # the named restore point to which recovery will proceed
#recovery_target_time = '' # the time stamp up to which recovery will proceed
#recovery_target_xid = '' # the transaction ID up to which recovery will proceed
#recovery_target_lsn = '' # the WAL LSN up to which recovery will proceed
#recovery_target_inclusive = on # Specifies whether to stop: just after the specified recovery target (on), or just before the recovery target (off)
#recovery_target_timeline = 'latest' # 'current', 'latest', or timeline ID
#recovery_target_action = 'pause' # 'pause', 'promote', 'shutdown'
#------------------------------------------------------------------------------
# REPLICATION
#------------------------------------------------------------------------------
# - Sending Servers -
# Set these on the primary and on any standby that will send replication data.
#max_wal_senders = 10 # max number of walsender processes
#max_replication_slots = 10 # max number of replication slots
#wal_keep_size = 0 # in megabytes; 0 disables
#max_slot_wal_keep_size = -1 # in megabytes; -1 disables
#wal_sender_timeout = 60s # in milliseconds; 0 disables
#track_commit_timestamp = off # collect timestamp of transaction commit
# - Primary 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 primary server.
#primary_conninfo = '' # connection string to sending server
#primary_slot_name = '' # replication slot on sending server
#promote_trigger_file = '' # file name whose presence ends recovery
#hot_standby = on # "off" disallows queries during recovery
#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_create_temp_slot = off # create temp slot if primary_slot_name is not set
#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 primary 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
#max_sync_workers_per_subscription = 2 # taken from max_logical_replication_workers
#------------------------------------------------------------------------------
# QUERY TUNING
#------------------------------------------------------------------------------
# - Planner Method Configuration -
#enable_async_append = on
#enable_bitmapscan = on
#enable_gathermerge = on
#enable_hashagg = on
#enable_hashjoin = on
#enable_incremental_sort = on
#enable_indexscan = on
#enable_indexonlyscan = on
#enable_material = on
#enable_memoize = on
#enable_mergejoin = on
#enable_nestloop = on
#enable_parallel_append = on
#enable_parallel_hash = on
#enable_partition_pruning = on
#enable_partitionwise_join = off
#enable_partitionwise_aggregate = off
#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
#parallel_setup_cost = 1000.0 # same scale as above
#parallel_tuple_cost = 0.1 # same scale as above
#min_parallel_table_scan_size = 8MB
#min_parallel_index_scan_size = 512kB
#effective_cache_size = 4GB
#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
# - 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
#jit = on # allow JIT compilation
#join_collapse_limit = 8 # 1 disables collapsing of explicit JOIN clauses
#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 = off # Enable capturing of stderr and csvlog into log files. Required to be on for csvlogs.
# These are only used if logging_collector is on:
#log_directory = '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_file_mode = 0600 # creation mode for log files, begin with 0 to use octal notation
#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.
#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.
# 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 (Windows):
#event_source = 'PostgreSQL'
# - When to Log -
# Values for log_min_messages and log_min_error_statement:
# debug5
# debug4
# debug3
# debug2
# debug1
# info
# notice
# warning
# error
# log
# fatal
# panic
log_min_messages = info
log_min_error_statement = info # see values on line 368; 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_min_duration_sample = -1 # -1 is disabled, 0 logs a sample of statements and their durations, > 0 logs only a sample of statements running at least this number of milliseconds; sample fraction is determined by log_statement_sample_rate
#log_statement_sample_rate = 1.0 # fraction of logged statements exceeding log_min_duration_sample to be logged; 1.0 logs all such statements, 0.0 never logs
#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 = on
#log_autovacuum_min_duration = -1 # log autovacuum activity; -1 disables, 0 logs all actions and their durations, > 0 logs only actions running at least this number of milliseconds.
#log_checkpoints = off
#log_connections = off
#log_disconnections = off
#log_duration = off
#log_error_verbosity = default # terse, default, or verbose messages
#log_hostname = off
# Placeholders for log_line_prefix:
# %a = application name
# %u = user name
# %d = database name
# %r = remote host and port
# %h = remote host
# %b = backend type
# %p = process ID
# %P = process ID of parallel group leader
# %t = timestamp without milliseconds
# %m = timestamp with milliseconds
# %n = timestamp with milliseconds (as a Unix epoch)
# %Q = query ID (0 if none or not computed)
# %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
# %% = '%'
#log_line_prefix = '%m [%p] '
#log_lock_waits = off # log lock waits >= deadlock_timeout
#log_recovery_conflict_waits = off # log standby recovery conflict waits >= deadlock_timeout
#log_parameter_max_length = -1 # when logging statements, limit logged bind-parameter values to N bytes; -1 means print in full, 0 disables
#log_parameter_max_length_on_error = 0 # when logging an error, limit logged bind-parameter values to N bytes; -1 means print in full, 0 disables
#log_statement = 'none' # 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 files
#log_timezone = 'GMT'
#------------------------------------------------------------------------------
# PROCESS TITLE
#------------------------------------------------------------------------------
#cluster_name = '' # added to process titles if nonempty
#update_process_title = on
#------------------------------------------------------------------------------
# STATISTICS
#------------------------------------------------------------------------------
# - Query and Index Statistics Collector -
#track_activities = on
#track_activity_query_size = 1024
#track_counts = on
#track_io_timing = off
#track_wal_io_timing = off
#track_functions = none # none, pl, all
#stats_temp_directory = 'pg_stat_tmp'
# - Monitoring -
#compute_query_id = auto
#log_statement_stats = off
#log_parser_stats = off
#log_planner_stats = off
#log_executor_stats = off
#------------------------------------------------------------------------------
# AUTOVACUUM
#------------------------------------------------------------------------------
#autovacuum = on # Enable autovacuum subprocess? 'on' requires track_counts to also be on.
#autovacuum_max_workers = 3 # max number of autovacuum subprocesses
#autovacuum_naptime = 1min # time between autovacuum runs
#autovacuum_vacuum_threshold = 50 # min number of row updates before vacuum
#autovacuum_vacuum_insert_threshold = 1000 # min number of row inserts before vacuum; -1 disables insert vacuums
#autovacuum_analyze_threshold = 50 # min number of row updates before analyze
#autovacuum_vacuum_scale_factor = 0.2 # fraction of table size before vacuum
#autovacuum_vacuum_insert_scale_factor = 0.2 # fraction of inserts over table size before insert vacuum
#autovacuum_analyze_scale_factor = 0.1 # fraction of table size before analyze
#autovacuum_freeze_max_age = 200000000 # maximum XID age before forced vacuum
#autovacuum_multixact_freeze_max_age = 400000000 # maximum multixact age before forced vacuum
#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 -
# Values for client_min_messages:
# debug5
# debug4
# debug3
# debug2
# debug1
# log
# notice
# warning
# error
#client_min_messages = notice
#search_path = '"$user", public' # schema names
#row_security = on
#default_table_access_method = 'heap'
#default_tablespace = '' # a tablespace name, '' uses the default
#default_toast_compression = 'pglz' # 'pglz' or 'lz4'
#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
#default_transaction_deferrable = off
#session_replication_role = 'origin'
#statement_timeout = 0 # in milliseconds, 0 is disabled
#lock_timeout = 0 # in milliseconds, 0 is disabled
#idle_in_transaction_session_timeout = 0 # in milliseconds, 0 is disabled
#idle_session_timeout = 0 # in milliseconds, 0 is disabled
#vacuum_freeze_table_age = 150000000
#vacuum_freeze_min_age = 50000000
#vacuum_failsafe_age = 1600000000
#vacuum_multixact_freeze_table_age = 150000000
#vacuum_multixact_freeze_min_age = 5000000
#vacuum_multixact_failsafe_age = 1600000000
#bytea_output = 'hex' # hex, escape
#xmlbinary = 'base64'
#xmloption = 'content'
#gin_pending_list_limit = 4MB
# - Locale and Formatting -
#datestyle = 'iso, mdy'
#intervalstyle = 'postgres'
#timezone = 'GMT'
#timezone_abbreviations = 'Default' # Select the set of available time zone abbreviations; 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 = '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
# default configuration for text search
#default_text_search_config = 'pg_catalog.simple'
# - Shared Library Preloading -
#local_preload_libraries = ''
#session_preload_libraries = ''
#shared_preload_libraries = '' # (change requires restart)
#jit_provider = 'llvmjit' # JIT library to use
# - Other Defaults -
#dynamic_library_path = '$libdir'
#gin_fuzzy_search_limit = 0
#------------------------------------------------------------------------------
# LOCK MANAGEMENT
#------------------------------------------------------------------------------
#deadlock_timeout = 1s
#max_locks_per_transaction = 64 # min 10
#max_pred_locks_per_transaction = 64 # min 10
#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
#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 = on # reinitialize after backend crash?
#data_sync_retry = off # retry or panic on failure to fsync data?
#recovery_init_sync_method = fsync # fsync, syncfs (Linux 5.8+)
#------------------------------------------------------------------------------
# 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
#------------------------------------------------------------------------------
Usage
The psql(1) utility is a convenient terminal client. See here for details on how to use it.
The connection string is structured as postgresql://postgres@localhost:5432/dbname?sslmode=disable. Naturally, if the connection should be encrypted, do not include the sslmode=disable component.