--- --- test functionality of SET/RESET --- select * from pg_settings where name not in ('config_file','data_directory','hba_file','ident_file') order by name; name | setting | category | short_desc | extra_desc | context | vartype | source | min_val | max_val ---------------------------------+--------------------------------+-------------------------------------------------------------------+----------------------------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+------------+---------+----------------------+---------+-------------- DateStyle | Postgres, MDY | Client Connection Defaults / Locale and Formatting | Sets the display format for date and time values. | Also controls interpretation of ambiguous date inputs. | user | string | client | | TimeZone | PST8PDT | Client Connection Defaults / Locale and Formatting | Sets the time zone for displaying and interpreting time stamps. | | user | string | client | | add_missing_from | off | Version and Platform Compatibility / Previous PostgreSQL Versions | Automatically adds missing table references to FROM clauses. | | user | bool | default | | allow_system_table_mods | off | Developer Options | Allows modifications of the structure of system tables. | | postmaster | bool | default | | archive_command | unset | Write-Ahead Log / Settings | WAL archiving command. | The shell command that will be called to archive a WAL file. | sighup | string | default | | array_nulls | on | Version and Platform Compatibility / Previous PostgreSQL Versions | Enable input of NULL elements in arrays. | When turned on, unquoted NULL in an array input value means a NULL value; otherwise it is taken literally. | user | bool | default | | australian_timezones | off | Client Connection Defaults / Locale and Formatting | Interprets ACST, CST, EST, and SAT as Australian time zones. | Otherwise they are interpreted as North/South American time zones and Saturday. | user | bool | default | | authentication_timeout | 60 | Connections and Authentication / Security and Authentication | Sets the maximum time in seconds to complete client authentication. | | sighup | integer | default | 1 | 600 autovacuum | off | Autovacuum | Starts the autovacuum subprocess. | | sighup | bool | default | | autovacuum_analyze_scale_factor | 0.2 | Autovacuum | Number of tuple inserts, updates or deletes prior to analyze as a fraction of reltuples. | | sighup | real | default | 0 | 100 autovacuum_analyze_threshold | 500 | Autovacuum | Minimum number of tuple inserts, updates or deletes prior to analyze. | | sighup | integer | default | 0 | 2147483647 autovacuum_naptime | 60 | Autovacuum | Time to sleep between autovacuum runs, in seconds. | | sighup | integer | default | 1 | 2147483647 autovacuum_vacuum_cost_delay | -1 | Autovacuum | Vacuum cost delay in milliseconds, for autovacuum. | | sighup | integer | default | -1 | 1000 autovacuum_vacuum_cost_limit | -1 | Autovacuum | Vacuum cost amount available before napping, for autovacuum. | | sighup | integer | default | -1 | 10000 autovacuum_vacuum_scale_factor | 0.4 | Autovacuum | Number of tuple updates or deletes prior to vacuum as a fraction of reltuples. | | sighup | real | default | 0 | 100 autovacuum_vacuum_threshold | 1000 | Autovacuum | Minimum number of tuple updates or deletes prior to vacuum. | | sighup | integer | default | 0 | 2147483647 bgwriter_all_maxpages | 5 | Resource Usage | Background writer maximum number of all pages to flush per round | | sighup | integer | default | 0 | 1000 bgwriter_all_percent | 0.333 | Resource Usage | Background writer percentage of all buffers to flush per round | | sighup | real | default | 0 | 100 bgwriter_delay | 200 | Resource Usage | Background writer sleep time between rounds in milliseconds | | sighup | integer | default | 10 | 10000 bgwriter_lru_maxpages | 5 | Resource Usage | Background writer maximum number of LRU pages to flush per round | | sighup | integer | default | 0 | 1000 bgwriter_lru_percent | 1 | Resource Usage | Background writer percentage of LRU buffers to flush per round | | sighup | real | default | 0 | 100 block_size | 8192 | Preset Options | Shows size of a disk block | | internal | integer | default | 8192 | 8192 bonjour_name | unset | Connections and Authentication / Connection Settings | Sets the Bonjour broadcast service name. | | postmaster | string | default | | check_function_bodies | on | Client Connection Defaults / Statement Behavior | Check function bodies during CREATE FUNCTION. | | user | bool | default | | checkpoint_segments | 3 | Write-Ahead Log / Checkpoints | Sets the maximum distance in log segments between automatic WAL checkpoints. | | sighup | integer | default | 1 | 2147483647 checkpoint_timeout | 300 | Write-Ahead Log / Checkpoints | Sets the maximum time in seconds between automatic WAL checkpoints. | | sighup | integer | default | 30 | 3600 checkpoint_warning | 30 | Write-Ahead Log / Checkpoints | Logs if filling of checkpoint segments happens more frequently than this (in seconds). | Write a message to the server log if checkpoints caused by the filling of checkpoint segment files happens more frequently than this number of seconds. Zero turns off the warning. | sighup | integer | default | 0 | 2147483647 client_encoding | SQL_ASCII | Client Connection Defaults / Locale and Formatting | Sets the client's character set encoding. | | user | string | client | | client_min_messages | notice | Reporting and Logging / When to Log | Sets the message levels that are sent to the client. | Valid values are DEBUG5, DEBUG4, DEBUG3, DEBUG2, DEBUG1, LOG, NOTICE, WARNING, and ERROR. Each level includes all the levels that follow it. The later the level, the fewer messages are sent. | user | string | default | | commit_delay | 0 | Write-Ahead Log / Checkpoints | Sets the delay in microseconds between transaction commit and flushing WAL to disk. | | user | integer | default | 0 | 100000 commit_siblings | 5 | Write-Ahead Log / Checkpoints | Sets the minimum concurrent open transactions before performing commit_delay. | | user | integer | default | 1 | 1000 constraint_exclusion | off | Query Tuning / Other Planner Options | Enables the planner to use constraints to optimize queries. | Child table scans will be skipped if their constraints guarantee that no rows match the query. | user | bool | default | | cpu_index_tuple_cost | 0.001 | Query Tuning / Planner Cost Constants | Sets the planner's estimate of processing cost for each index tuple (row) during index scan. | This is measured as a fraction of the cost of a sequential page fetch. | user | real | default | 0 | 1.79769e+308 cpu_operator_cost | 0.0025 | Query Tuning / Planner Cost Constants | Sets the planner's estimate of processing cost of each operator in WHERE. | This is measured as a fraction of the cost of a sequential page fetch. | user | real | default | 0 | 1.79769e+308 cpu_tuple_cost | 0.01 | Query Tuning / Planner Cost Constants | Sets the planner's estimate of the cost of processing each tuple (row). | This is measured as a fraction of the cost of a sequential page fetch. | user | real | default | 0 | 1.79769e+308 custom_variable_classes | unset | Customized Options | Sets the list of known custom variable classes. | | sighup | string | default | | db_user_namespace | off | Connections and Authentication / Security and Authentication | Enables per-database user names. | | sighup | bool | default | | deadlock_timeout | 1000 | Lock Management | The time in milliseconds to wait on lock before checking for deadlock. | | sighup | integer | default | 0 | 2147483647 debug_assertions | off | Developer Options | Turns on various assertion checks. | This is a debugging aid. | user | bool | default | | debug_pretty_print | off | Reporting and Logging / What to Log | Indents parse and plan tree displays. | | user | bool | default | | debug_print_parse | off | Reporting and Logging / What to Log | Prints the parse tree to the server log. | | user | bool | default | | debug_print_plan | off | Reporting and Logging / What to Log | Prints the execution plan to server log. | | user | bool | default | | debug_print_rewritten | off | Reporting and Logging / What to Log | Prints the parse tree after rewriting to server log. | | user | bool | default | | default_statistics_target | 10 | Query Tuning / Other Planner Options | Sets the default statistics target. | This applies to table columns that have not had a column-specific target set via ALTER TABLE SET STATISTICS. | user | integer | default | 1 | 1000 default_tablespace | unset | Client Connection Defaults / Statement Behavior | Sets the default tablespace to create tables and indexes in. | An empty string selects the database's default tablespace. | user | string | default | | default_transaction_isolation | read committed | Client Connection Defaults / Statement Behavior | Sets the transaction isolation level of each new transaction. | Each SQL transaction has an isolation level, which can be either "read uncommitted", "read committed", "repeatable read", or "serializable". | user | string | default | | default_transaction_read_only | off | Client Connection Defaults / Statement Behavior | Sets the default read-only status of new transactions. | | user | bool | default | | default_with_oids | off | Version and Platform Compatibility / Previous PostgreSQL Versions | Create new tables with OIDs by default. | | user | bool | default | | dynamic_library_path | $libdir | Client Connection Defaults / Other Defaults | Sets the path for dynamically loadable modules. | If a dynamically loadable module needs to be opened and the specified name does not have a directory component (i.e., the name does not contain a slash), the system will search this path for the specified file. | superuser | string | default | | effective_cache_size | 1000 | Query Tuning / Planner Cost Constants | Sets the planner's assumption about size of the disk cache. | That is, the portion of the kernel's disk cache that will be used for PostgreSQL data files. This is measured in disk pages, which are normally 8 kB each. | user | real | default | 1 | 1.79769e+308 enable_bitmapscan | on | Query Tuning / Planner Method Configuration | Enables the planner's use of bitmap-scan plans. | | user | bool | default | | enable_hashagg | on | Query Tuning / Planner Method Configuration | Enables the planner's use of hashed aggregation plans. | | user | bool | default | | enable_hashjoin | on | Query Tuning / Planner Method Configuration | Enables the planner's use of hash join plans. | | user | bool | default | | enable_indexscan | on | Query Tuning / Planner Method Configuration | Enables the planner's use of index-scan plans. | | user | bool | default | | enable_mergejoin | on | Query Tuning / Planner Method Configuration | Enables the planner's use of merge join plans. | | user | bool | default | | enable_nestloop | on | Query Tuning / Planner Method Configuration | Enables the planner's use of nested-loop join plans. | | user | bool | default | | enable_seqscan | on | Query Tuning / Planner Method Configuration | Enables the planner's use of sequential-scan plans. | | user | bool | default | | enable_sort | on | Query Tuning / Planner Method Configuration | Enables the planner's use of explicit sort steps. | | user | bool | default | | enable_tidscan | on | Query Tuning / Planner Method Configuration | Enables the planner's use of TID scan plans. | | user | bool | default | | escape_string_warning | on | Version and Platform Compatibility / Previous PostgreSQL Versions | Warn about backslash escapes in ordinary string literals. | | user | bool | default | | explain_pretty_print | on | Client Connection Defaults / Other Defaults | Uses the indented output format for EXPLAIN VERBOSE. | | user | bool | default | | external_pid_file | unset | File Locations | Writes the postmaster PID to the specified file. | | postmaster | string | default | | extra_float_digits | 0 | Client Connection Defaults / Locale and Formatting | Sets the number of digits displayed for floating-point values. | This affects real, double precision, and geometric data types. The parameter value is added to the standard number of digits (FLT_DIG or DBL_DIG as appropriate). | user | integer | default | -15 | 2 from_collapse_limit | 8 | Query Tuning / Other Planner Options | Sets the FROM-list size beyond which subqueries are not collapsed. | The planner will merge subqueries into upper queries if the resulting FROM list would have no more than this many items. | user | integer | default | 1 | 2147483647 fsync | off | Write-Ahead Log / Settings | Forces synchronization of updates to disk. | The server will use the fsync() system call in several places to make sure that updates are physically written to disk. This insures that a database cluster will recover to a consistent state after an operating system or hardware crash. | sighup | bool | command line | | full_page_writes | on | Write-Ahead Log / Settings | Writes full pages to WAL when first modified after a checkpoint. | A page write in process during an operating system crash might be only partially written to disk. During recovery, the row changes stored in WAL are not enough to recover. This option writes pages when first modified after a checkpoint to WAL so full recovery is possible. | sighup | bool | default | | geqo | on | Query Tuning / Genetic Query Optimizer | Enables genetic query optimization. | This algorithm attempts to do planning without exhaustive searching. | user | bool | default | | geqo_effort | 5 | Query Tuning / Genetic Query Optimizer | GEQO: effort is used to set the default for other GEQO parameters. | | user | integer | default | 1 | 10 geqo_generations | 0 | Query Tuning / Genetic Query Optimizer | GEQO: number of iterations of the algorithm. | Zero selects a suitable default value. | user | integer | default | 0 | 2147483647 geqo_pool_size | 0 | Query Tuning / Genetic Query Optimizer | GEQO: number of individuals in the population. | Zero selects a suitable default value. | user | integer | default | 0 | 2147483647 geqo_selection_bias | 2 | Query Tuning / Genetic Query Optimizer | GEQO: selective pressure within the population. | | user | real | default | 1.5 | 2 geqo_threshold | 12 | Query Tuning / Genetic Query Optimizer | Sets the threshold of FROM items beyond which GEQO is used. | | user | integer | default | 2 | 2147483647 gin_fuzzy_search_limit | 0 | Ungrouped | Sets the maximum allowed result for exact search by gin. | | user | integer | default | 0 | 2147483647 ignore_system_indexes | off | Developer Options | Disabled reading from system indexes. | It does not prevent updating the indexes, so it is safe to use. The worst consequence is slowness. | backend | bool | default | | integer_datetimes | off | Preset Options | Datetimes are integer based. | | internal | bool | default | | join_collapse_limit | 8 | Query Tuning / Other Planner Options | Sets the FROM-list size beyond which JOIN constructs are not flattened. | The planner will flatten explicit JOIN constructs into lists of FROM items whenever a list of no more than this many items would result. | user | integer | default | 1 | 2147483647 krb_caseins_users | off | Connections and Authentication / Security and Authentication | Sets whether Kerberos user names should be treated as case-insensitive. | | postmaster | bool | default | | krb_server_hostname | unset | Connections and Authentication / Security and Authentication | Sets the hostname of the Kerberos server. | | postmaster | string | default | | krb_server_keyfile | unset | Connections and Authentication / Security and Authentication | Sets the location of the Kerberos server key file. | | postmaster | string | default | | krb_srvname | postgres | Connections and Authentication / Security and Authentication | Sets the name of the Kerberos service. | | postmaster | string | default | | lc_collate | C | Client Connection Defaults / Locale and Formatting | Shows the collation order locale. | | internal | string | override | | lc_ctype | C | Client Connection Defaults / Locale and Formatting | Shows the character classification and case conversion locale. | | internal | string | override | | lc_messages | C | Client Connection Defaults / Locale and Formatting | Sets the language in which messages are displayed. | | superuser | string | database | | lc_monetary | C | Client Connection Defaults / Locale and Formatting | Sets the locale for formatting monetary amounts. | | user | string | database | | lc_numeric | C | Client Connection Defaults / Locale and Formatting | Sets the locale for formatting numbers. | | user | string | database | | lc_time | C | Client Connection Defaults / Locale and Formatting | Sets the locale for formatting date and time values. | | user | string | database | | listen_addresses | unset | Connections and Authentication / Connection Settings | Sets the host name or IP address(es) to listen to. | | postmaster | string | command line | | log_connections | off | Reporting and Logging / What to Log | Logs each successful connection. | | backend | bool | default | | log_destination | stderr | Reporting and Logging / Where to Log | Sets the destination for server log output. | Valid values are combinations of "stderr", "syslog", and "eventlog", depending on the platform. | sighup | string | default | | log_directory | pg_log | Reporting and Logging / Where to Log | Sets the destination directory for log files. | May be specified as relative to the data directory or as absolute path. | sighup | string | default | | log_disconnections | off | Reporting and Logging / What to Log | Logs end of a session, including duration. | | backend | bool | default | | log_duration | off | Reporting and Logging / What to Log | Logs the duration of each completed SQL statement. | | superuser | bool | default | | log_error_verbosity | default | Reporting and Logging / When to Log | Sets the verbosity of logged messages. | Valid values are "terse", "default", and "verbose". | superuser | string | default | | log_executor_stats | off | Statistics / Monitoring | Writes executor performance statistics to the server log. | | superuser | bool | default | | log_filename | postgresql-%Y-%m-%d_%H%M%S.log | Reporting and Logging / Where to Log | Sets the file name pattern for log files. | | sighup | string | default | | log_hostname | off | Reporting and Logging / What to Log | Logs the host name in the connection logs. | By default, connection logs only show the IP address of the connecting host. If you want them to show the host name you can turn this on, but depending on your host name resolution setup it might impose a non-negligible performance penalty. | sighup | bool | default | | log_line_prefix | unset | Reporting and Logging / What to Log | Controls information prefixed to each log line | if blank no prefix is used | sighup | string | default | | log_min_duration_statement | -1 | Reporting and Logging / When to Log | Sets the minimum execution time in milliseconds above which statements will be logged. | Zero prints all queries. The default is -1 (turning this feature off). | superuser | integer | default | -1 | 2147483 log_min_error_statement | panic | Reporting and Logging / When to Log | Causes all statements generating error at or above this level to be logged. | All SQL statements that cause an error of the specified level or a higher level are logged. | superuser | string | default | | log_min_messages | notice | Reporting and Logging / When to Log | Sets the message levels that are logged. | Valid values are DEBUG5, DEBUG4, DEBUG3, DEBUG2, DEBUG1, INFO, NOTICE, WARNING, ERROR, LOG, FATAL, and PANIC. Each level includes all the levels that follow it. | superuser | string | default | | log_parser_stats | off | Statistics / Monitoring | Writes parser performance statistics to the server log. | | superuser | bool | default | | log_planner_stats | off | Statistics / Monitoring | Writes planner performance statistics to the server log. | | superuser | bool | default | | log_rotation_age | 1440 | Reporting and Logging / Where to Log | Automatic log file rotation will occur after N minutes | | sighup | integer | default | 0 | 35791394 log_rotation_size | 10240 | Reporting and Logging / Where to Log | Automatic log file rotation will occur after N kilobytes | | sighup | integer | default | 0 | 2097151 log_statement | none | Reporting and Logging / What to Log | Sets the type of statements logged. | Valid values are "none", "ddl", "mod", and "all". | superuser | string | default | | log_statement_stats | off | Statistics / Monitoring | Writes cumulative performance statistics to the server log. | | superuser | bool | default | | log_truncate_on_rotation | off | Reporting and Logging / Where to Log | Truncate existing log files of same name during log rotation. | | sighup | bool | default | | maintenance_work_mem | 16384 | Resource Usage / Memory | Sets the maximum memory to be used for maintenance operations. | This includes operations such as VACUUM and CREATE INDEX. | user | integer | default | 1024 | 2097151 max_connections | 100 | Connections and Authentication / Connection Settings | Sets the maximum number of concurrent connections. | | postmaster | integer | configuration file | 1 | 536870911 max_files_per_process | 1000 | Resource Usage / Kernel Resources | Sets the maximum number of simultaneously open files for each server process. | | postmaster | integer | default | 25 | 2147483647 max_fsm_pages | 200000 | Resource Usage / Free Space Map | Sets the maximum number of disk pages for which free space is tracked. | | postmaster | integer | configuration file | 1000 | 2147483647 max_fsm_relations | 1000 | Resource Usage / Free Space Map | Sets the maximum number of tables and indexes for which free space is tracked. | | postmaster | integer | default | 100 | 2147483647 max_function_args | 100 | Preset Options | Shows the maximum number of function arguments. | | internal | integer | default | 100 | 100 max_identifier_length | 63 | Preset Options | Shows the maximum identifier length | | internal | integer | default | 63 | 63 max_index_keys | 32 | Preset Options | Shows the maximum number of index keys. | | internal | integer | default | 32 | 32 max_locks_per_transaction | 64 | Lock Management | Sets the maximum number of locks per transaction. | The shared lock table is sized on the assumption that at most max_locks_per_transaction * max_connections distinct objects will need to be locked at any one time. | postmaster | integer | default | 10 | 2147483647 max_prepared_transactions | 5 | Resource Usage | Sets the maximum number of simultaneously prepared transactions. | | postmaster | integer | default | 0 | 2147483647 max_stack_depth | 2048 | Resource Usage / Memory | Sets the maximum stack depth, in kilobytes. | | superuser | integer | default | 100 | 2097151 password_encryption | on | Connections and Authentication / Security and Authentication | Encrypt passwords. | When a password is specified in CREATE USER or ALTER USER without writing either ENCRYPTED or UNENCRYPTED, this parameter determines whether the password is to be encrypted. | user | bool | default | | port | 55432 | Connections and Authentication / Connection Settings | Sets the TCP port the server listens on. | | postmaster | integer | environment variable | 1 | 65535 post_auth_delay | 0 | Developer Options | Waits N seconds on connection startup after authentication. | This allows attaching a debugger to the process. | backend | integer | default | 0 | 2147483647 pre_auth_delay | 0 | Developer Options | no description available | | sighup | integer | default | 0 | 60 preload_libraries | unset | Resource Usage / Kernel Resources | Lists shared libraries to preload into server. | | postmaster | string | default | | random_page_cost | 4 | Query Tuning / Planner Cost Constants | Sets the planner's estimate of the cost of a nonsequentially fetched disk page. | This is measured as a multiple of the cost of a sequential page fetch. A higher value makes it more likely a sequential scan will be used, a lower value makes it more likely an index scan will be used. | user | real | default | 0 | 1.79769e+308 redirect_stderr | off | Reporting and Logging / Where to Log | Start a subprocess to capture stderr output into log files. | | postmaster | bool | default | | regex_flavor | advanced | Version and Platform Compatibility / Previous PostgreSQL Versions | Sets the regular expression "flavor". | This can be set to advanced, extended, or basic. | user | string | default | | search_path | "$user",public | Client Connection Defaults / Statement Behavior | Sets the schema search order for names that are not schema-qualified. | | user | string | default | | server_encoding | SQL_ASCII | Client Connection Defaults / Locale and Formatting | Sets the server (database) character set encoding. | | internal | string | override | | server_version | 8.2devel | Preset Options | Shows the server version. | | internal | string | default | | shared_buffers | 4000 | Resource Usage / Memory | Sets the number of shared memory buffers used by the server. | | postmaster | integer | configuration file | 16 | 1073741823 silent_mode | off | Reporting and Logging / When to Log | Runs the server silently. | If this parameter is set, the server will automatically run in the background and any controlling terminals are dissociated. | postmaster | bool | default | | sql_inheritance | on | Version and Platform Compatibility / Previous PostgreSQL Versions | Causes subtables to be included by default in various commands. | | user | bool | default | | ssl | off | Connections and Authentication / Security and Authentication | Enables SSL connections. | | postmaster | bool | default | | standard_conforming_strings | off | Version and Platform Compatibility / Previous PostgreSQL Versions | '...' strings treat backslashes literally. | | user | bool | default | | statement_timeout | 0 | Client Connection Defaults / Statement Behavior | Sets the maximum allowed duration (in milliseconds) of any statement. | A value of 0 turns off the timeout. | user | integer | default | 0 | 2147483647 stats_block_level | off | Statistics / Query and Index Statistics Collector | Collects block-level statistics on database activity. | | superuser | bool | default | | stats_command_string | off | Statistics / Query and Index Statistics Collector | Collects statistics about executing commands. | Enables the collection of statistics on the currently executing command of each session, along with the time at which that command began execution. | superuser | bool | default | | stats_reset_on_server_start | off | Statistics / Query and Index Statistics Collector | Zeroes collected statistics on server restart. | | postmaster | bool | default | | stats_row_level | off | Statistics / Query and Index Statistics Collector | Collects row-level statistics on database activity. | | superuser | bool | default | | stats_start_collector | on | Statistics / Query and Index Statistics Collector | Starts the server statistics-collection subprocess. | | postmaster | bool | default | | superuser_reserved_connections | 2 | Connections and Authentication / Connection Settings | Sets the number of connection slots reserved for superusers. | | postmaster | integer | default | 0 | 536870911 syslog_facility | LOCAL0 | Reporting and Logging / Where to Log | Sets the syslog "facility" to be used when syslog enabled. | Valid values are LOCAL0, LOCAL1, LOCAL2, LOCAL3, LOCAL4, LOCAL5, LOCAL6, LOCAL7. | sighup | string | default | | syslog_ident | postgres | Reporting and Logging / Where to Log | Sets the program name used to identify PostgreSQL messages in syslog. | | sighup | string | default | | tcp_keepalives_count | 0 | Client Connection Defaults / Other Defaults | Maximum number of TCP keepalive retransmits. | This controls the number of consecutive keepalive retransmits that can be lost before a connection is considered dead. A value of 0 uses the system default. | user | integer | default | 0 | 2147483647 tcp_keepalives_idle | 0 | Client Connection Defaults / Other Defaults | Seconds between issuing TCP keepalives. | A value of 0 uses the system default. | user | integer | default | 0 | 2147483647 tcp_keepalives_interval | 0 | Client Connection Defaults / Other Defaults | Seconds between TCP keepalive retransmits. | A value of 0 uses the system default. | user | integer | default | 0 | 2147483647 temp_buffers | 1000 | Resource Usage / Memory | Sets the maximum number of temporary buffers used by each session. | | user | integer | default | 100 | 1073741823 trace_notify | off | Developer Options | Generates debugging output for LISTEN and NOTIFY. | | user | bool | default | | trace_sort | off | Developer Options | Emit information about resource usage in sorting. | | user | bool | default | | transaction_isolation | read committed | Client Connection Defaults / Statement Behavior | Sets the current transaction's isolation level. | | user | string | override | | transaction_read_only | off | Client Connection Defaults / Statement Behavior | Sets the current transaction's read-only status. | | user | bool | override | | transform_null_equals | off | Version and Platform Compatibility / Other Platforms and Clients | Treats "expr=NULL" as "expr IS NULL". | When turned on, expressions of the form expr = NULL (or NULL = expr) are treated as expr IS NULL, that is, they return true if expr evaluates to the null value, and false otherwise. The correct behavior of expr = NULL is to always return null (unknown). | user | bool | default | | unix_socket_directory | unset | Connections and Authentication / Connection Settings | Sets the directory where the Unix-domain socket will be created. | | postmaster | string | default | | unix_socket_group | unset | Connections and Authentication / Connection Settings | Sets the owning group of the Unix-domain socket. | (The owning user of the socket is always the user that starts the server.) | postmaster | string | default | | unix_socket_permissions | 511 | Connections and Authentication / Connection Settings | Sets the access permissions of the Unix-domain socket. | Unix-domain sockets use the usual Unix file system permission set. The parameter value is expected to be an numeric mode specification in the form accepted by the chmod and umask system calls. (To use the customary octal format the number must start with a 0 (zero).) | postmaster | integer | default | 0 | 511 vacuum_cost_delay | 0 | Resource Usage | Vacuum cost delay in milliseconds. | | user | integer | default | 0 | 1000 vacuum_cost_limit | 200 | Resource Usage | Vacuum cost amount available before napping. | | user | integer | default | 1 | 10000 vacuum_cost_page_dirty | 20 | Resource Usage | Vacuum cost for a page dirtied by vacuum. | | user | integer | default | 0 | 10000 vacuum_cost_page_hit | 1 | Resource Usage | Vacuum cost for a page found in the buffer cache. | | user | integer | default | 0 | 10000 vacuum_cost_page_miss | 10 | Resource Usage | Vacuum cost for a page not found in the buffer cache. | | user | integer | default | 0 | 10000 wal_buffers | 8 | Write-Ahead Log / Settings | Sets the number of disk-page buffers in shared memory for WAL. | | postmaster | integer | default | 4 | 2147483647 wal_sync_method | open_datasync | Write-Ahead Log / Settings | Selects the method used for forcing WAL updates out to disk. | | sighup | string | default | | work_mem | 1024 | Resource Usage / Memory | Sets the maximum memory to be used for query workspaces. | This much memory may be used by each internal sort operation and hash table before switching to temporary disk files. | user | integer | default | 64 | 2097151 zero_damaged_pages | off | Developer Options | Continues processing past damaged page headers. | Detection of a damaged page header normally causes PostgreSQL to report an error, aborting the current transaction. Setting zero_damaged_pages to true causes the system to instead report a warning, zero out the damaged page, and continue processing. This behavior will destroy data, namely all the rows on the damaged page. | superuser | bool | default | | (164 rows) SHOW enable_bitmapscan; enable_bitmapscan ------------------- on (1 row) BEGIN TRANSACTION; SET enable_bitmapscan = off; ROLLBACK; SHOW enable_bitmapscan; enable_bitmapscan ------------------- on (1 row) BEGIN TRANSACTION; SET enable_bitmapscan = off; COMMIT; SHOW enable_bitmapscan; enable_bitmapscan ------------------- off (1 row) RESET enable_bitmapscan; SHOW enable_bitmapscan; enable_bitmapscan ------------------- on (1 row)