postgres=# SHOW ALL; name | setting | description ----------------------------------------+--------------------------------+------------------------------------------------------------------------------------------------------------------------------- allow_system_table_mods | off | Allows modifications of the structure of system tables. application_name | psql | Sets the application name to be reported in statistics and logs. archive_command | (disabled) | Sets the shell command that will be called to archive a WAL file. archive_mode | off | Allows archiving of WAL files using archive_command. archive_timeout | 0 | Forces a switch to the next WAL file if a new file has not been started within N seconds. array_nulls | on | Enable input of NULL elements in arrays. authentication_timeout | 1min | Sets the maximum allowed time to complete client authentication. autovacuum | on | Starts the autovacuum subprocess. autovacuum_analyze_scale_factor | 0.1 | Number of tuple inserts, updates, or deletes prior to analyze as a fraction of reltuples. autovacuum_analyze_threshold | 50 | Minimum number of tuple inserts, updates, or deletes prior to analyze. autovacuum_freeze_max_age | 200000000 | Age at which to autovacuum a table to prevent transaction ID wraparound. autovacuum_max_workers | 3 | Sets the maximum number of simultaneously running autovacuum worker processes. autovacuum_multixact_freeze_max_age | 400000000 | Multixact age at which to autovacuum a table to prevent multixact wraparound. autovacuum_naptime | 1min | Time to sleep between autovacuum runs. autovacuum_vacuum_cost_delay | 20ms | Vacuum cost delay in milliseconds, for autovacuum. autovacuum_vacuum_cost_limit | -1 | Vacuum cost amount available before napping, for autovacuum. autovacuum_vacuum_scale_factor | 0.2 | Number of tuple updates or deletes prior to vacuum as a fraction of reltuples. autovacuum_vacuum_threshold | 50 | Minimum number of tuple updates or deletes prior to vacuum. autovacuum_work_mem | -1 | Sets the maximum memory to be used by each autovacuum worker process. backend_flush_after | 0 | Number of pages after which previously performed writes are flushed to disk. backslash_quote | safe_encoding | Sets whether "\'" is allowed in string literals. bgwriter_delay | 200ms | Background writer sleep time between rounds. bgwriter_flush_after | 512kB | Number of pages after which previously performed writes are flushed to disk. bgwriter_lru_maxpages | 100 | Background writer maximum number of LRU pages to flush per round. bgwriter_lru_multiplier | 2 | Multiple of the average buffer usage to free per round. block_size | 8192 | Shows the size of a disk block. bonjour | off | Enables advertising the server via Bonjour. bonjour_name | | Sets the Bonjour service name. bytea_output | hex | Sets the output format for bytea. check_function_bodies | on | Check function bodies during CREATE FUNCTION. checkpoint_completion_target | 0.5 | Time spent flushing dirty buffers during checkpoint, as fraction of checkpoint interval. checkpoint_flush_after | 256kB | Number of pages after which previously performed writes are flushed to disk. checkpoint_timeout | 5min | Sets the maximum time between automatic WAL checkpoints. checkpoint_warning | 30s | Enables warnings if checkpoint segments are filled more frequently than this. client_encoding | UTF8 | Sets the client's character set encoding. client_min_messages | notice | Sets the message levels that are sent to the client. cluster_name | | Sets the name of the cluster, which is included in the process title. commit_delay | 0 | Sets the delay in microseconds between transaction commit and flushing WAL to disk. commit_siblings | 5 | Sets the minimum concurrent open transactions before performing commit_delay. config_file | /db/data/postgresql.conf | Sets the server's main configuration file. constraint_exclusion | partition | Enables the planner to use constraints to optimize queries. cpu_index_tuple_cost | 0.005 | Sets the planner's estimate of the cost of processing each index entry during an index scan. cpu_operator_cost | 0.0025 | Sets the planner's estimate of the cost of processing each operator or function call. cpu_tuple_cost | 0.01 | Sets the planner's estimate of the cost of processing each tuple (row). cursor_tuple_fraction | 0.1 | Sets the planner's estimate of the fraction of a cursor's rows that will be retrieved. data_checksums | off | Shows whether data checksums are turned on for this cluster. data_directory | /db/data | Sets the server's data directory. data_directory_mode | 0700 | Mode of the data directory. data_sync_retry | off | Whether to continue running after a failure to sync data files. DateStyle | ISO, MDY | Sets the display format for date and time values. db_user_namespace | off | Enables per-database user names. deadlock_timeout | 1s | Sets the time to wait on a lock before checking for deadlock. debug_assertions | off | Shows whether the running server has assertion checks enabled. debug_pretty_print | on | Indents parse and plan tree displays. debug_print_parse | off | Logs each query's parse tree. debug_print_plan | off | Logs each query's execution plan. debug_print_rewritten | off | Logs each query's rewritten parse tree. default_statistics_target | 100 | Sets the default statistics target. default_tablespace | | Sets the default tablespace to create tables and indexes in. default_text_search_config | pg_catalog.english | Sets default text search configuration. default_transaction_deferrable | off | Sets the default deferrable status of new transactions. default_transaction_isolation | read committed | Sets the transaction isolation level of each new transaction. default_transaction_read_only | off | Sets the default read-only status of new transactions. default_with_oids | off | Create new tables with OIDs by default. dynamic_library_path | $libdir | Sets the path for dynamically loadable modules. dynamic_shared_memory_type | posix | Selects the dynamic shared memory implementation used. effective_cache_size | 4GB | Sets the planner's assumption about the total size of the data caches. effective_io_concurrency | 1 | Number of simultaneous requests that can be handled efficiently by the disk subsystem. enable_bitmapscan | on | Enables the planner's use of bitmap-scan plans. enable_gathermerge | on | Enables the planner's use of gather merge plans. enable_hashagg | on | Enables the planner's use of hashed aggregation plans. enable_hashjoin | on | Enables the planner's use of hash join plans. enable_indexonlyscan | on | Enables the planner's use of index-only-scan plans. enable_indexscan | on | Enables the planner's use of index-scan plans. enable_material | on | Enables the planner's use of materialization. enable_mergejoin | on | Enables the planner's use of merge join plans. enable_nestloop | on | Enables the planner's use of nested-loop join plans. enable_parallel_append | on | Enables the planner's use of parallel append plans. enable_parallel_hash | on | Enables the planner's use of parallel hash plans. enable_partition_pruning | on | Enable plan-time and run-time partition pruning. enable_partitionwise_aggregate | off | Enables partitionwise aggregation and grouping. enable_partitionwise_join | off | Enables partitionwise join. enable_seqscan | on | Enables the planner's use of sequential-scan plans. enable_sort | on | Enables the planner's use of explicit sort steps. enable_tidscan | on | Enables the planner's use of TID scan plans. escape_string_warning | on | Warn about backslash escapes in ordinary string literals. event_source | PostgreSQL | Sets the application name used to identify PostgreSQL messages in the event log. exit_on_error | off | Terminate session on any error. external_pid_file | | Writes the postmaster PID to the specified file. extra_float_digits | 0 | Sets the number of digits displayed for floating-point values. force_parallel_mode | off | Forces use of parallel query facilities. from_collapse_limit | 8 | Sets the FROM-list size beyond which subqueries are not collapsed. fsync | on | Forces synchronization of updates to disk. full_page_writes | on | Writes full pages to WAL when first modified after a checkpoint. geqo | on | Enables genetic query optimization. geqo_effort | 5 | GEQO: effort is used to set the default for other GEQO parameters. geqo_generations | 0 | GEQO: number of iterations of the algorithm. geqo_pool_size | 0 | GEQO: number of individuals in the population. geqo_seed | 0 | GEQO: seed for random path selection. geqo_selection_bias | 2 | GEQO: selective pressure within the population. geqo_threshold | 12 | Sets the threshold of FROM items beyond which GEQO is used. gin_fuzzy_search_limit | 0 | Sets the maximum allowed result for exact search by GIN. gin_pending_list_limit | 4MB | Sets the maximum size of the pending list for GIN index. hba_file | /db/data/pg_hba.conf | Sets the server's "hba" configuration file. hot_standby | on | Allows connections and queries during recovery. hot_standby_feedback | off | Allows feedback from a hot standby to the primary that will avoid query conflicts. huge_pages | try | Use of huge pages on Linux or Windows. ident_file | /db/data/pg_ident.conf | Sets the server's "ident" configuration file. idle_in_transaction_session_timeout | 0 | Sets the maximum allowed duration of any idling transaction. ignore_checksum_failure | off | Continues processing after a checksum failure. ignore_system_indexes | off | Disables reading from system indexes. integer_datetimes | on | Datetimes are integer based. IntervalStyle | postgres | Sets the display format for interval values. jit | off | Allow JIT compilation. jit_above_cost | 100000 | Perform JIT compilation if query is more expensive. jit_debugging_support | off | Register JIT compiled function with debugger. jit_dump_bitcode | off | Write out LLVM bitcode to facilitate JIT debugging. jit_expressions | on | Allow JIT compilation of expressions. jit_inline_above_cost | 500000 | Perform JIT inlining if query is more expensive. jit_optimize_above_cost | 500000 | Optimize JITed functions if query is more expensive. jit_profiling_support | off | Register JIT compiled function with perf profiler. jit_provider | llvmjit | JIT provider to use. jit_tuple_deforming | on | Allow JIT compilation of tuple deforming. join_collapse_limit | 8 | Sets the FROM-list size beyond which JOIN constructs are not flattened. krb_caseins_users | off | Sets whether Kerberos and GSSAPI user names should be treated as case-insensitive. krb_server_keyfile | | Sets the location of the Kerberos server key file. lc_collate | en_US.utf8 | Shows the collation order locale. lc_ctype | en_US.utf8 | Shows the character classification and case conversion locale. lc_messages | en_US.utf8 | Sets the language in which messages are displayed. lc_monetary | en_US.utf8 | Sets the locale for formatting monetary amounts. lc_numeric | en_US.utf8 | Sets the locale for formatting numbers. lc_time | en_US.utf8 | Sets the locale for formatting date and time values. listen_addresses | * | Sets the host name or IP address(es) to listen to. lo_compat_privileges | off | Enables backward compatibility mode for privilege checks on large objects. local_preload_libraries | | Lists unprivileged shared libraries to preload into each backend. lock_timeout | 0 | Sets the maximum allowed duration of any wait for a lock. log_autovacuum_min_duration | -1 | Sets the minimum execution time above which autovacuum actions will be logged. log_checkpoints | off | Logs each checkpoint. log_connections | off | Logs each successful connection. log_destination | stderr | Sets the destination for server log output. log_directory | log | Sets the destination directory for log files. log_disconnections | off | Logs end of a session, including duration. log_duration | off | Logs the duration of each completed SQL statement. log_error_verbosity | default | Sets the verbosity of logged messages. log_executor_stats | off | Writes executor performance statistics to the server log. log_file_mode | 0600 | Sets the file permissions for log files. log_filename | postgresql-%Y-%m-%d_%H%M%S.log | Sets the file name pattern for log files. log_hostname | off | Logs the host name in the connection logs. log_line_prefix | %m [%p] | Controls information prefixed to each log line. log_lock_waits | off | Logs long lock waits. log_min_duration_statement | -1 | Sets the minimum execution time above which statements will be logged. log_min_error_statement | error | Causes all statements generating error at or above this level to be logged. log_min_messages | warning | Sets the message levels that are logged. log_parser_stats | off | Writes parser performance statistics to the server log. log_planner_stats | off | Writes planner performance statistics to the server log. log_replication_commands | off | Logs each replication command. log_rotation_age | 1d | Automatic log file rotation will occur after N minutes. log_rotation_size | 10MB | Automatic log file rotation will occur after N kilobytes. log_statement | none | Sets the type of statements logged. log_statement_stats | off | Writes cumulative performance statistics to the server log. log_temp_files | -1 | Log the use of temporary files larger than this number of kilobytes. log_timezone | UTC | Sets the time zone to use in log messages. log_truncate_on_rotation | off | Truncate existing log files of same name during log rotation. logging_collector | off | Start a subprocess to capture stderr output and/or csvlogs into log files. maintenance_work_mem | 64MB | Sets the maximum memory to be used for maintenance operations. max_connections | 100 | Sets the maximum number of concurrent connections. max_files_per_process | 1000 | Sets the maximum number of simultaneously open files for each server process. max_function_args | 100 | Shows the maximum number of function arguments. max_identifier_length | 63 | Shows the maximum identifier length. max_index_keys | 32 | Shows the maximum number of index keys. max_locks_per_transaction | 64 | Sets the maximum number of locks per transaction. max_logical_replication_workers | 4 | Maximum number of logical replication worker processes. max_parallel_maintenance_workers | 2 | Sets the maximum number of parallel processes per maintenance operation. max_parallel_workers | 8 | Sets the maximum number of parallel workers that can be active at one time. max_parallel_workers_per_gather | 2 | Sets the maximum number of parallel processes per executor node. max_pred_locks_per_page | 2 | Sets the maximum number of predicate-locked tuples per page. max_pred_locks_per_relation | -2 | Sets the maximum number of predicate-locked pages and tuples per relation. max_pred_locks_per_transaction | 64 | Sets the maximum number of predicate locks per transaction. max_prepared_transactions | 0 | Sets the maximum number of simultaneously prepared transactions. max_replication_slots | 10 | Sets the maximum number of simultaneously defined replication slots. max_stack_depth | 2MB | Sets the maximum stack depth, in kilobytes. max_standby_archive_delay | 30s | Sets the maximum delay before canceling queries when a hot standby server is processing archived WAL data. max_standby_streaming_delay | 30s | Sets the maximum delay before canceling queries when a hot standby server is processing streamed WAL data. max_sync_workers_per_subscription | 2 | Maximum number of table synchronization workers per subscription. max_wal_senders | 10 | Sets the maximum number of simultaneously running WAL sender processes. max_wal_size | 1GB | Sets the WAL size that triggers a checkpoint. max_worker_processes | 8 | Maximum number of concurrent worker processes. min_parallel_index_scan_size | 512kB | Sets the minimum amount of index data for a parallel scan. min_parallel_table_scan_size | 8MB | Sets the minimum amount of table data for a parallel scan. min_wal_size | 80MB | Sets the minimum size to shrink the WAL to. old_snapshot_threshold | -1 | Time before a snapshot is too old to read pages changed after the snapshot was taken. operator_precedence_warning | off | Emit a warning for constructs that changed meaning since PostgreSQL 9.4. parallel_leader_participation | on | Controls whether Gather and Gather Merge also run subplans. parallel_setup_cost | 1000 | Sets the planner's estimate of the cost of starting up worker processes for parallel query. parallel_tuple_cost | 0.1 | Sets the planner's estimate of the cost of passing each tuple (row) from worker to master backend. password_encryption | md5 | Chooses the algorithm for encrypting passwords. port | 5432 | Sets the TCP port the server listens on. post_auth_delay | 0 | Waits N seconds on connection startup after authentication. pre_auth_delay | 0 | Waits N seconds on connection startup before authentication. quote_all_identifiers | off | When generating SQL fragments, quote all identifiers. random_page_cost | 4 | Sets the planner's estimate of the cost of a nonsequentially fetched disk page. restart_after_crash | on | Reinitialize server after backend crash. row_security | on | Enable row security. search_path | "$user", public | Sets the schema search order for names that are not schema-qualified. segment_size | 1GB | Shows the number of pages per disk file. seq_page_cost | 1 | Sets the planner's estimate of the cost of a sequentially fetched disk page. server_encoding | UTF8 | Sets the server (database) character set encoding. server_version | 11.9 | Shows the server version. server_version_num | 110009 | Shows the server version as an integer. session_preload_libraries | | Lists shared libraries to preload into each backend. session_replication_role | origin | Sets the session's behavior for triggers and rewrite rules. shared_buffers | 128MB | Sets the number of shared memory buffers used by the server. shared_preload_libraries | | Lists shared libraries to preload into server. ssl | off | Enables SSL connections. ssl_ca_file | | Location of the SSL certificate authority file. ssl_cert_file | server.crt | Location of the SSL server certificate file. ssl_ciphers | HIGH:MEDIUM:+3DES:!aNULL | Sets the list of allowed SSL ciphers. ssl_crl_file | | Location of the SSL certificate revocation list file. ssl_dh_params_file | | Location of the SSL DH parameters file. ssl_ecdh_curve | prime256v1 | Sets the curve to use for ECDH. ssl_key_file | server.key | Location of the SSL server private key file. ssl_passphrase_command | | Command to obtain passphrases for SSL. ssl_passphrase_command_supports_reload | off | Also use ssl_passphrase_command during server reload. ssl_prefer_server_ciphers | on | Give priority to server ciphersuite order. standard_conforming_strings | on | Causes '...' strings to treat backslashes literally. statement_timeout | 0 | Sets the maximum allowed duration of any statement. stats_temp_directory | pg_stat_tmp | Writes temporary statistics files to the specified directory. superuser_reserved_connections | 3 | Sets the number of connection slots reserved for superusers. synchronize_seqscans | on | Enable synchronized sequential scans. synchronous_commit | on | Sets the current transaction's synchronization level. synchronous_standby_names | | Number of synchronous standbys and list of names of potential synchronous ones. syslog_facility | local0 | Sets the syslog "facility" to be used when syslog enabled. syslog_ident | postgres | Sets the program name used to identify PostgreSQL messages in syslog. syslog_sequence_numbers | on | Add sequence number to syslog messages to avoid duplicate suppression. syslog_split_messages | on | Split messages sent to syslog by lines and to fit into 1024 bytes. tcp_keepalives_count | 0 | Maximum number of TCP keepalive retransmits. tcp_keepalives_idle | 0 | Time between issuing TCP keepalives. tcp_keepalives_interval | 0 | Time between TCP keepalive retransmits. temp_buffers | 8MB | Sets the maximum number of temporary buffers used by each session. temp_file_limit | -1 | Limits the total size of all temporary files used by each process. temp_tablespaces | | Sets the tablespace(s) to use for temporary tables and sort files. TimeZone | UTC | Sets the time zone for displaying and interpreting time stamps. timezone_abbreviations | Default | Selects a file of time zone abbreviations. trace_notify | off | Generates debugging output for LISTEN and NOTIFY. trace_recovery_messages | log | Enables logging of recovery-related debugging information. trace_sort | off | Emit information about resource usage in sorting. track_activities | on | Collects information about executing commands. track_activity_query_size | 1kB | Sets the size reserved for pg_stat_activity.query, in bytes. track_commit_timestamp | off | Collects transaction commit time. track_counts | on | Collects statistics on database activity. track_functions | none | Collects function-level statistics on database activity. track_io_timing | off | Collects timing statistics for database I/O activity. transaction_deferrable | off | Whether to defer a read-only serializable transaction until it can be executed with no possible serialization failures. transaction_isolation | read committed | Sets the current transaction's isolation level. transaction_read_only | off | Sets the current transaction's read-only status. transform_null_equals | off | Treats "expr=NULL" as "expr IS NULL". unix_socket_directories | /var/run/postgresql | Sets the directories where Unix-domain sockets will be created. unix_socket_group | | Sets the owning group of the Unix-domain socket. unix_socket_permissions | 0777 | Sets the access permissions of the Unix-domain socket. update_process_title | on | Updates the process title to show the active SQL command. vacuum_cleanup_index_scale_factor | 0.1 | Number of tuple inserts prior to index cleanup as a fraction of reltuples. vacuum_cost_delay | 0 | Vacuum cost delay in milliseconds. vacuum_cost_limit | 200 | Vacuum cost amount available before napping. vacuum_cost_page_dirty | 20 | Vacuum cost for a page dirtied by vacuum. vacuum_cost_page_hit | 1 | Vacuum cost for a page found in the buffer cache. vacuum_cost_page_miss | 10 | Vacuum cost for a page not found in the buffer cache. vacuum_defer_cleanup_age | 0 | Number of transactions by which VACUUM and HOT cleanup should be deferred, if any. vacuum_freeze_min_age | 50000000 | Minimum age at which VACUUM should freeze a table row. vacuum_freeze_table_age | 150000000 | Age at which VACUUM should scan whole table to freeze tuples. vacuum_multixact_freeze_min_age | 5000000 | Minimum age at which VACUUM should freeze a MultiXactId in a table row. vacuum_multixact_freeze_table_age | 150000000 | Multixact age at which VACUUM should scan whole table to freeze tuples. wal_block_size | 8192 | Shows the block size in the write ahead log. wal_buffers | 4MB | Sets the number of disk-page buffers in shared memory for WAL. wal_compression | off | Compresses full-page writes written in WAL file. wal_consistency_checking | | Sets the WAL resource managers for which WAL consistency checks are done. wal_keep_segments | 0 | Sets the number of WAL files held for standby servers. wal_level | replica | Set the level of information written to the WAL. wal_log_hints | off | Writes full pages to WAL when first modified after a checkpoint, even for a non-critical modifications. wal_receiver_status_interval | 10s | Sets the maximum interval between WAL receiver status reports to the primary. wal_receiver_timeout | 1min | Sets the maximum wait time to receive data from the primary. wal_retrieve_retry_interval | 5s | Sets the time to wait before retrying to retrieve WAL after a failed attempt. wal_segment_size | 16MB | Shows the size of write ahead log segments. wal_sender_timeout | 1min | Sets the maximum time to wait for WAL replication. wal_sync_method | fdatasync | Selects the method used for forcing WAL updates to disk. wal_writer_delay | 200ms | Time between WAL flushes performed in the WAL writer. wal_writer_flush_after | 1MB | Amount of WAL written out by WAL writer that triggers a flush. work_mem | 4MB | Sets the maximum memory to be used for query workspaces. xmlbinary | base64 | Sets how binary values are to be encoded in XML. xmloption | content | Sets whether XML data in implicit parsing and serialization operations is to be considered as documents or content fragments. zero_damaged_pages | off | Continues processing past damaged page headers.