archive_command	sighup	Write-Ahead Log / Archiving	STRING				Sets the shell command that will be called to archive a WAL file.	
archive_mode	postmaster	Write-Ahead Log / Archiving	ENUM	off			Allows archiving of WAL files using archive_command.	
archive_timeout	sighup	Write-Ahead Log / Archiving	INTEGER	0	0	1073741823	Forces a switch to the next xlog file if a new file has not been started within N seconds.	
array_nulls	user	Version and Platform Compatibility / Previous PostgreSQL Versions	BOOLEAN	FALSE			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.
authentication_timeout	sighup	Connections and Authentication / Security and Authentication	INTEGER	0	1	600	Sets the maximum allowed time to complete client authentication.	
autovacuum	sighup	Autovacuum	BOOLEAN	FALSE			Starts the autovacuum subprocess.	
autovacuum_analyze_scale_factor	sighup	Autovacuum	REAL	0	0	100	Number of tuple inserts, updates, or deletes prior to analyze as a fraction of reltuples.	
autovacuum_analyze_threshold	sighup	Autovacuum	INTEGER	0	0	2147483647	Minimum number of tuple inserts, updates, or deletes prior to analyze.	
autovacuum_freeze_max_age	postmaster	Autovacuum	INTEGER	0	100000	2000000000	Age at which to autovacuum a table to prevent transaction ID wraparound.	
autovacuum_max_workers	postmaster	Autovacuum	INTEGER	0	1	262143	Sets the maximum number of simultaneously running autovacuum worker processes.	
autovacuum_multixact_freeze_max_age	postmaster	Autovacuum	INTEGER	0	10000	2000000000	Multixact age at which to autovacuum a table to prevent multixact wraparound.	
autovacuum_naptime	sighup	Autovacuum	INTEGER	0	1	2147483	Time to sleep between autovacuum runs.	
autovacuum_vacuum_cost_delay	sighup	Autovacuum	INTEGER	0	-1	100	Vacuum cost delay in milliseconds, for autovacuum.	
autovacuum_vacuum_cost_limit	sighup	Autovacuum	INTEGER	0	-1	10000	Vacuum cost amount available before napping, for autovacuum.	
autovacuum_vacuum_scale_factor	sighup	Autovacuum	REAL	0	0	100	Number of tuple updates or deletes prior to vacuum as a fraction of reltuples.	
autovacuum_vacuum_threshold	sighup	Autovacuum	INTEGER	0	0	2147483647	Minimum number of tuple updates or deletes prior to vacuum.	
autovacuum_work_mem	sighup	Resource Usage / Memory	INTEGER	0	-1	2147483647	Sets the maximum memory to be used by each autovacuum worker process.	
backend_flush_after	user	Resource Usage / Asynchronous Behavior	INTEGER	0	0	256	Number of pages after which previously performed writes are flushed to disk.	
backslash_quote	user	Version and Platform Compatibility / Previous PostgreSQL Versions	ENUM	safe_encoding			Sets whether "\'" is allowed in string literals.	
bgwriter_delay	sighup	Resource Usage / Background Writer	INTEGER	0	10	10000	Background writer sleep time between rounds.	
bgwriter_flush_after	sighup	Resource Usage / Background Writer	INTEGER	0	0	256	Number of pages after which previously performed writes are flushed to disk.	
bgwriter_lru_maxpages	sighup	Resource Usage / Background Writer	INTEGER	0	0	1000	Background writer maximum number of LRU pages to flush per round.	
bgwriter_lru_multiplier	sighup	Resource Usage / Background Writer	REAL	0	0	10	Multiple of the average buffer usage to free per round.	
bonjour	postmaster	Connections and Authentication / Connection Settings	BOOLEAN	FALSE			Enables advertising the server via Bonjour.	
bonjour_name	postmaster	Connections and Authentication / Connection Settings	STRING				Sets the Bonjour service name.	
bytea_output	user	Client Connection Defaults / Statement Behavior	ENUM	hex			Sets the output format for bytea.	
check_function_bodies	user	Client Connection Defaults / Statement Behavior	BOOLEAN	FALSE			Check function bodies during CREATE FUNCTION.	
checkpoint_completion_target	sighup	Write-Ahead Log / Checkpoints	REAL	0	0	1	Time spent flushing dirty buffers during checkpoint, as fraction of checkpoint interval.	
checkpoint_flush_after	sighup	Write-Ahead Log / Checkpoints	INTEGER	0	0	256	Number of pages after which previously performed writes are flushed to disk.	
checkpoint_timeout	sighup	Write-Ahead Log / Checkpoints	INTEGER	0	30	86400	Sets the maximum time between automatic WAL checkpoints.	
checkpoint_warning	sighup	Write-Ahead Log / Checkpoints	INTEGER	0	0	2147483647	Enables warnings if checkpoint segments are filled more frequently than this.	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.
client_encoding	user	Client Connection Defaults / Locale and Formatting	STRING	SQL_ASCII			Sets the client's character set encoding.	
client_min_messages	user	Reporting and Logging / When to Log	ENUM	notice			Sets the message levels that are sent to the client.	Each level includes all the levels that follow it. The later the level, the fewer messages are sent.
cluster_name	postmaster	Process Title	STRING				Sets the name of the cluster, which is included in the process title.	
commit_delay	superuser	Write-Ahead Log / Settings	INTEGER	0	0	100000	Sets the delay in microseconds between transaction commit and flushing WAL to disk.	
commit_siblings	user	Write-Ahead Log / Settings	INTEGER	0	0	1000	Sets the minimum concurrent open transactions before performing commit_delay.	
constraint_exclusion	user	Query Tuning / Other Planner Options	ENUM	partition			Enables the planner to use constraints to optimize queries.	Table scans will be skipped if their constraints guarantee that no rows match the query.
cpu_index_tuple_cost	user	Query Tuning / Planner Cost Constants	REAL	0	0	1.79769e+308	Sets the planner's estimate of the cost of processing each index entry during an index scan.	
cpu_operator_cost	user	Query Tuning / Planner Cost Constants	REAL	0	0	1.79769e+308	Sets the planner's estimate of the cost of processing each operator or function call.	
cpu_tuple_cost	user	Query Tuning / Planner Cost Constants	REAL	0	0	1.79769e+308	Sets the planner's estimate of the cost of processing each tuple (row).	
cursor_tuple_fraction	user	Query Tuning / Other Planner Options	REAL	0	0	1	Sets the planner's estimate of the fraction of a cursor's rows that will be retrieved.	
data_directory	postmaster	File Locations	STRING				Sets the server's data directory.	
DateStyle	user	Client Connection Defaults / Locale and Formatting	STRING	ISO, MDY			Sets the display format for date and time values.	Also controls interpretation of ambiguous date inputs.
db_user_namespace	sighup	Connections and Authentication / Security and Authentication	BOOLEAN	FALSE			Enables per-database user names.	
deadlock_timeout	superuser	Lock Management	INTEGER	0	1	2147483647	Sets the time to wait on a lock before checking for deadlock.	
debug_pretty_print	user	Reporting and Logging / What to Log	BOOLEAN	FALSE			Indents parse and plan tree displays.	
debug_print_parse	user	Reporting and Logging / What to Log	BOOLEAN	FALSE			Logs each query's parse tree.	
debug_print_plan	user	Reporting and Logging / What to Log	BOOLEAN	FALSE			Logs each query's execution plan.	
debug_print_rewritten	user	Reporting and Logging / What to Log	BOOLEAN	FALSE			Logs each query's rewritten parse tree.	
default_statistics_target	user	Query Tuning / Other Planner Options	INTEGER	0	1	10000	Sets the default statistics target.	This applies to table columns that have not had a column-specific target set via ALTER TABLE SET STATISTICS.
default_tablespace	user	Client Connection Defaults / Statement Behavior	STRING				Sets the default tablespace to create tables and indexes in.	An empty string selects the database's default tablespace.
default_text_search_config	user	Client Connection Defaults / Locale and Formatting	STRING	pg_catalog.simple			Sets default text search configuration.	
default_transaction_deferrable	user	Client Connection Defaults / Statement Behavior	BOOLEAN	FALSE			Sets the default deferrable status of new transactions.	
default_transaction_isolation	user	Client Connection Defaults / Statement Behavior	ENUM	read committed			Sets the transaction isolation level of each new transaction.	
default_transaction_read_only	user	Client Connection Defaults / Statement Behavior	BOOLEAN	FALSE			Sets the default read-only status of new transactions.	
default_with_oids	user	Version and Platform Compatibility / Previous PostgreSQL Versions	BOOLEAN	FALSE			Create new tables with OIDs by default.	
dynamic_library_path	superuser	Client Connection Defaults / Other Defaults	STRING	$libdir			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.
dynamic_shared_memory_type	postmaster	Resource Usage / Memory	ENUM	posix			Selects the dynamic shared memory implementation used.	
effective_cache_size	user	Query Tuning / Planner Cost Constants	INTEGER	0	1	2147483647	Sets the planner's assumption about the 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.
effective_io_concurrency	user	Resource Usage / Asynchronous Behavior	INTEGER	0	0	1000	Number of simultaneous requests that can be handled efficiently by the disk subsystem.	For RAID arrays, this should be approximately the number of drive spindles in the array.
enable_bitmapscan	user	Query Tuning / Planner Method Configuration	BOOLEAN	FALSE			Enables the planner's use of bitmap-scan plans.	
enable_hashagg	user	Query Tuning / Planner Method Configuration	BOOLEAN	FALSE			Enables the planner's use of hashed aggregation plans.	
enable_hashjoin	user	Query Tuning / Planner Method Configuration	BOOLEAN	FALSE			Enables the planner's use of hash join plans.	
enable_indexonlyscan	user	Query Tuning / Planner Method Configuration	BOOLEAN	FALSE			Enables the planner's use of index-only-scan plans.	
enable_indexscan	user	Query Tuning / Planner Method Configuration	BOOLEAN	FALSE			Enables the planner's use of index-scan plans.	
enable_material	user	Query Tuning / Planner Method Configuration	BOOLEAN	FALSE			Enables the planner's use of materialization.	
enable_mergejoin	user	Query Tuning / Planner Method Configuration	BOOLEAN	FALSE			Enables the planner's use of merge join plans.	
enable_nestloop	user	Query Tuning / Planner Method Configuration	BOOLEAN	FALSE			Enables the planner's use of nested-loop join plans.	
enable_seqscan	user	Query Tuning / Planner Method Configuration	BOOLEAN	FALSE			Enables the planner's use of sequential-scan plans.	
enable_sort	user	Query Tuning / Planner Method Configuration	BOOLEAN	FALSE			Enables the planner's use of explicit sort steps.	
enable_tidscan	user	Query Tuning / Planner Method Configuration	BOOLEAN	FALSE			Enables the planner's use of TID scan plans.	
escape_string_warning	user	Version and Platform Compatibility / Previous PostgreSQL Versions	BOOLEAN	FALSE			Warn about backslash escapes in ordinary string literals.	
event_source	postmaster	Reporting and Logging / Where to Log	STRING	PostgreSQL			Sets the application name used to identify PostgreSQL messages in the event log.	
exit_on_error	user	Error Handling	BOOLEAN	FALSE			Terminate session on any error.	
external_pid_file	postmaster	File Locations	STRING				Writes the postmaster PID to the specified file.	
extra_float_digits	user	Client Connection Defaults / Locale and Formatting	INTEGER	0	-15	3	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).
force_parallel_mode	user	Query Tuning / Other Planner Options	ENUM	off			Forces use of parallel query facilities.	If possible, run query using a parallel worker and with parallel restrictions.
from_collapse_limit	user	Query Tuning / Other Planner Options	INTEGER	0	1	2147483647	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.
fsync	sighup	Write-Ahead Log / Settings	BOOLEAN	FALSE			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.
full_page_writes	sighup	Write-Ahead Log / Settings	BOOLEAN	FALSE			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.
geqo	user	Query Tuning / Genetic Query Optimizer	BOOLEAN	FALSE			Enables genetic query optimization.	This algorithm attempts to do planning without exhaustive searching.
geqo_effort	user	Query Tuning / Genetic Query Optimizer	INTEGER	0	1	10	GEQO: effort is used to set the default for other GEQO parameters.	
geqo_generations	user	Query Tuning / Genetic Query Optimizer	INTEGER	0	0	2147483647	GEQO: number of iterations of the algorithm.	Zero selects a suitable default value.
geqo_pool_size	user	Query Tuning / Genetic Query Optimizer	INTEGER	0	0	2147483647	GEQO: number of individuals in the population.	Zero selects a suitable default value.
geqo_seed	user	Query Tuning / Genetic Query Optimizer	REAL	0	0	1	GEQO: seed for random path selection.	
geqo_selection_bias	user	Query Tuning / Genetic Query Optimizer	REAL	0	1.5	2	GEQO: selective pressure within the population.	
geqo_threshold	user	Query Tuning / Genetic Query Optimizer	INTEGER	0	2	2147483647	Sets the threshold of FROM items beyond which GEQO is used.	
gin_fuzzy_search_limit	user	Client Connection Defaults / Other Defaults	INTEGER	0	0	2147483647	Sets the maximum allowed result for exact search by GIN.	
gin_pending_list_limit	user	Client Connection Defaults / Statement Behavior	INTEGER	0	64	2147483647	Sets the maximum size of the pending list for GIN index.	
hba_file	postmaster	File Locations	STRING				Sets the server's "hba" configuration file.	
hot_standby	postmaster	Replication / Standby Servers	BOOLEAN	FALSE			Allows connections and queries during recovery.	
hot_standby_feedback	sighup	Replication / Standby Servers	BOOLEAN	FALSE			Allows feedback from a hot standby to the primary that will avoid query conflicts.	
huge_pages	postmaster	Resource Usage / Memory	ENUM	try			Use of huge pages on Linux.	
ident_file	postmaster	File Locations	STRING				Sets the server's "ident" configuration file.	
idle_in_transaction_session_timeout	user	Client Connection Defaults / Statement Behavior	INTEGER	0	0	2147483647	Sets the maximum allowed duration of any idling transaction.	A value of 0 turns off the timeout.
IntervalStyle	user	Client Connection Defaults / Locale and Formatting	ENUM	postgres			Sets the display format for interval values.	
join_collapse_limit	user	Query Tuning / Other Planner Options	INTEGER	0	1	2147483647	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.
krb_caseins_users	sighup	Connections and Authentication / Security and Authentication	BOOLEAN	FALSE			Sets whether Kerberos and GSSAPI user names should be treated as case-insensitive.	
krb_server_keyfile	sighup	Connections and Authentication / Security and Authentication	STRING	FILE:/jet/etc/postgresql/krb5.keytab			Sets the location of the Kerberos server key file.	
lc_messages	superuser	Client Connection Defaults / Locale and Formatting	STRING				Sets the language in which messages are displayed.	
lc_monetary	user	Client Connection Defaults / Locale and Formatting	STRING	C			Sets the locale for formatting monetary amounts.	
lc_numeric	user	Client Connection Defaults / Locale and Formatting	STRING	C			Sets the locale for formatting numbers.	
lc_time	user	Client Connection Defaults / Locale and Formatting	STRING	C			Sets the locale for formatting date and time values.	
listen_addresses	postmaster	Connections and Authentication / Connection Settings	STRING	localhost			Sets the host name or IP address(es) to listen to.	
lo_compat_privileges	superuser	Version and Platform Compatibility / Previous PostgreSQL Versions	BOOLEAN	FALSE			Enables backward compatibility mode for privilege checks on large objects.	Skips privilege checks when reading or modifying large objects, for compatibility with PostgreSQL releases prior to 9.0.
local_preload_libraries	user	Client Connection Defaults / Shared Library Preloading	STRING				Lists unprivileged shared libraries to preload into each backend.	
lock_timeout	user	Client Connection Defaults / Statement Behavior	INTEGER	0	0	2147483647	Sets the maximum allowed duration of any wait for a lock.	A value of 0 turns off the timeout.
log_autovacuum_min_duration	sighup	Reporting and Logging / What to Log	INTEGER	0	-1	2147483647	Sets the minimum execution time above which autovacuum actions will be logged.	Zero prints all actions. -1 turns autovacuum logging off.
log_checkpoints	sighup	Reporting and Logging / What to Log	BOOLEAN	FALSE			Logs each checkpoint.	
log_connections	superuser-backend	Reporting and Logging / What to Log	BOOLEAN	FALSE			Logs each successful connection.	
log_destination	sighup	Reporting and Logging / Where to Log	STRING	stderr			Sets the destination for server log output.	Valid values are combinations of "stderr", "syslog", "csvlog", and "eventlog", depending on the platform.
log_directory	sighup	Reporting and Logging / Where to Log	STRING	pg_log			Sets the destination directory for log files.	Can be specified as relative to the data directory or as absolute path.
log_disconnections	superuser-backend	Reporting and Logging / What to Log	BOOLEAN	FALSE			Logs end of a session, including duration.	
log_duration	superuser	Reporting and Logging / What to Log	BOOLEAN	FALSE			Logs the duration of each completed SQL statement.	
log_error_verbosity	superuser	Reporting and Logging / What to Log	ENUM	default			Sets the verbosity of logged messages.	
log_executor_stats	superuser	Statistics / Monitoring	BOOLEAN	FALSE			Writes executor performance statistics to the server log.	
log_file_mode	sighup	Reporting and Logging / Where to Log	INTEGER	0	0	511	Sets the file permissions for log files.	The parameter value is expected to be a 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).)
log_filename	sighup	Reporting and Logging / Where to Log	STRING	postgresql-%Y-%m-%d_%H%M%S.log			Sets the file name pattern for log files.	
log_hostname	sighup	Reporting and Logging / What to Log	BOOLEAN	FALSE			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.
log_line_prefix	sighup	Reporting and Logging / What to Log	STRING				Controls information prefixed to each log line.	If blank, no prefix is used.
log_lock_waits	superuser	Reporting and Logging / What to Log	BOOLEAN	FALSE			Logs long lock waits.	
log_min_duration_statement	superuser	Reporting and Logging / When to Log	INTEGER	0	-1	2147483647	Sets the minimum execution time above which statements will be logged.	Zero prints all queries. -1 turns this feature off.
log_min_error_statement	superuser	Reporting and Logging / When to Log	ENUM	error			Causes all statements generating error at or above this level to be logged.	Each level includes all the levels that follow it. The later the level, the fewer messages are sent.
log_min_messages	superuser	Reporting and Logging / When to Log	ENUM	warning			Sets the message levels that are logged.	Each level includes all the levels that follow it. The later the level, the fewer messages are sent.
log_parser_stats	superuser	Statistics / Monitoring	BOOLEAN	FALSE			Writes parser performance statistics to the server log.	
log_planner_stats	superuser	Statistics / Monitoring	BOOLEAN	FALSE			Writes planner performance statistics to the server log.	
log_replication_commands	superuser	Reporting and Logging / What to Log	BOOLEAN	FALSE			Logs each replication command.	
log_rotation_age	sighup	Reporting and Logging / Where to Log	INTEGER	0	0	35791394	Automatic log file rotation will occur after N minutes.	
log_rotation_size	sighup	Reporting and Logging / Where to Log	INTEGER	0	0	2097151	Automatic log file rotation will occur after N kilobytes.	
log_statement	superuser	Reporting and Logging / What to Log	ENUM	none			Sets the type of statements logged.	
log_statement_stats	superuser	Statistics / Monitoring	BOOLEAN	FALSE			Writes cumulative performance statistics to the server log.	
log_temp_files	superuser	Reporting and Logging / What to Log	INTEGER	0	-1	2147483647	Log the use of temporary files larger than this number of kilobytes.	Zero logs all files. The default is -1 (turning this feature off).
log_timezone	sighup	Reporting and Logging / What to Log	STRING	GMT			Sets the time zone to use in log messages.	
log_truncate_on_rotation	sighup	Reporting and Logging / Where to Log	BOOLEAN	FALSE			Truncate existing log files of same name during log rotation.	
logging_collector	postmaster	Reporting and Logging / Where to Log	BOOLEAN	FALSE			Start a subprocess to capture stderr output and/or csvlogs into log files.	
maintenance_work_mem	user	Resource Usage / Memory	INTEGER	0	1024	2147483647	Sets the maximum memory to be used for maintenance operations.	This includes operations such as VACUUM and CREATE INDEX.
max_connections	postmaster	Connections and Authentication / Connection Settings	INTEGER	0	1	262143	Sets the maximum number of concurrent connections.	
max_files_per_process	postmaster	Resource Usage / Kernel Resources	INTEGER	0	25	2147483647	Sets the maximum number of simultaneously open files for each server process.	
max_locks_per_transaction	postmaster	Lock Management	INTEGER	0	10	2147483647	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.
max_parallel_workers_per_gather	user	Resource Usage / Asynchronous Behavior	INTEGER	0	0	1024	Sets the maximum number of parallel processes per executor node.	
max_pred_locks_per_transaction	postmaster	Lock Management	INTEGER	0	10	2147483647	Sets the maximum number of predicate locks per transaction.	The shared predicate lock table is sized on the assumption that at most max_pred_locks_per_transaction * max_connections distinct objects will need to be locked at any one time.
max_prepared_transactions	postmaster	Resource Usage / Memory	INTEGER	0	0	262143	Sets the maximum number of simultaneously prepared transactions.	
max_replication_slots	postmaster	Replication / Sending Servers	INTEGER	0	0	262143	Sets the maximum number of simultaneously defined replication slots.	
max_stack_depth	superuser	Resource Usage / Memory	INTEGER	0	100	2147483647	Sets the maximum stack depth, in kilobytes.	
max_standby_archive_delay	sighup	Replication / Standby Servers	INTEGER	0	-1	2147483647	Sets the maximum delay before canceling queries when a hot standby server is processing archived WAL data.	
max_standby_streaming_delay	sighup	Replication / Standby Servers	INTEGER	0	-1	2147483647	Sets the maximum delay before canceling queries when a hot standby server is processing streamed WAL data.	
max_wal_senders	postmaster	Replication / Sending Servers	INTEGER	0	0	262143	Sets the maximum number of simultaneously running WAL sender processes.	
max_wal_size	sighup	Write-Ahead Log / Checkpoints	INTEGER	0	2	2147483647	Sets the WAL size that triggers a checkpoint.	
max_worker_processes	postmaster	Resource Usage / Asynchronous Behavior	INTEGER	0	0	262143	Maximum number of concurrent worker processes.	
min_parallel_relation_size	user	Query Tuning / Planner Cost Constants	INTEGER	0	0	715827882	Sets the minimum size of relations to be considered for parallel scan.	
min_wal_size	sighup	Write-Ahead Log / Checkpoints	INTEGER	0	2	2147483647	Sets the minimum size to shrink the WAL to.	
old_snapshot_threshold	postmaster	Resource Usage / Asynchronous Behavior	INTEGER	0	-1	86400	Time before a snapshot is too old to read pages changed after the snapshot was taken.	A value of -1 disables this feature.
operator_precedence_warning	user	Version and Platform Compatibility / Previous PostgreSQL Versions	BOOLEAN	FALSE			Emit a warning for constructs that changed meaning since PostgreSQL 9.4.	
parallel_setup_cost	user	Query Tuning / Planner Cost Constants	REAL	0	0	1.79769e+308	Sets the planner's estimate of the cost of starting up worker processes for parallel query.	
parallel_tuple_cost	user	Query Tuning / Planner Cost Constants	REAL	0	0	1.79769e+308	Sets the planner's estimate of the cost of passing each tuple (row) from worker to master backend.	
password_encryption	user	Connections and Authentication / Security and Authentication	BOOLEAN	FALSE			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.
port	postmaster	Connections and Authentication / Connection Settings	INTEGER	0	1	65535	Sets the TCP port the server listens on.	
ptrack_enable	sighup	Write-Ahead Log / Settings	BOOLEAN	FALSE			Enable page tracking.	
quote_all_identifiers	user	Version and Platform Compatibility / Previous PostgreSQL Versions	BOOLEAN	FALSE			When generating SQL fragments, quote all identifiers.	
random_page_cost	user	Query Tuning / Planner Cost Constants	REAL	0	0	1.79769e+308	Sets the planner's estimate of the cost of a nonsequentially fetched disk page.	
replacement_sort_tuples	user	Resource Usage / Memory	INTEGER	0	0	2147483647	Sets the maximum number of tuples to be sorted using replacement selection.	When more tuples than this are present, quicksort will be used.
restart_after_crash	sighup	Error Handling	BOOLEAN	FALSE			Reinitialize server after backend crash.	
row_security	user	Connections and Authentication / Security and Authentication	BOOLEAN	FALSE			Enable row security.	When enabled, row security will be applied to all users.
search_path	user	Client Connection Defaults / Statement Behavior	STRING	"$user", public			Sets the schema search order for names that are not schema-qualified.	
seq_page_cost	user	Query Tuning / Planner Cost Constants	REAL	0	0	1.79769e+308	Sets the planner's estimate of the cost of a sequentially fetched disk page.	
session_preload_libraries	superuser	Client Connection Defaults / Shared Library Preloading	STRING				Lists shared libraries to preload into each backend.	
session_replication_role	superuser	Client Connection Defaults / Statement Behavior	ENUM	origin			Sets the session's behavior for triggers and rewrite rules.	
shared_buffers	postmaster	Resource Usage / Memory	INTEGER	0	16	1073741823	Sets the number of shared memory buffers used by the server.	
shared_preload_libraries	postmaster	Client Connection Defaults / Shared Library Preloading	STRING				Lists shared libraries to preload into server.	
sql_inheritance	user	Version and Platform Compatibility / Previous PostgreSQL Versions	BOOLEAN	FALSE			Causes subtables to be included by default in various commands.	
ssl	postmaster	Connections and Authentication / Security and Authentication	BOOLEAN	FALSE			Enables SSL connections.	
ssl_ca_file	postmaster	Connections and Authentication / Security and Authentication	STRING				Location of the SSL certificate authority file.	
ssl_cert_file	postmaster	Connections and Authentication / Security and Authentication	STRING	server.crt			Location of the SSL server certificate file.	
ssl_ciphers	postmaster	Connections and Authentication / Security and Authentication	STRING	HIGH:MEDIUM:+3DES:!aNULL			Sets the list of allowed SSL ciphers.	
ssl_crl_file	postmaster	Connections and Authentication / Security and Authentication	STRING				Location of the SSL certificate revocation list file.	
ssl_ecdh_curve	postmaster	Connections and Authentication / Security and Authentication	STRING	prime256v1			Sets the curve to use for ECDH.	
ssl_key_file	postmaster	Connections and Authentication / Security and Authentication	STRING	server.key			Location of the SSL server private key file.	
ssl_prefer_server_ciphers	postmaster	Connections and Authentication / Security and Authentication	BOOLEAN	FALSE			Give priority to server ciphersuite order.	
standard_conforming_strings	user	Version and Platform Compatibility / Previous PostgreSQL Versions	BOOLEAN	FALSE			Causes '...' strings to treat backslashes literally.	
statement_timeout	user	Client Connection Defaults / Statement Behavior	INTEGER	0	0	2147483647	Sets the maximum allowed duration of any statement.	A value of 0 turns off the timeout.
stats_temp_directory	sighup	Statistics / Query and Index Statistics Collector	STRING	pg_stat_tmp			Writes temporary statistics files to the specified directory.	
superuser_reserved_connections	postmaster	Connections and Authentication / Connection Settings	INTEGER	0	0	262143	Sets the number of connection slots reserved for superusers.	
synchronize_seqscans	user	Version and Platform Compatibility / Previous PostgreSQL Versions	BOOLEAN	FALSE			Enable synchronized sequential scans.	
synchronous_commit	user	Write-Ahead Log / Settings	ENUM	on			Sets the current transaction's synchronization level.	
synchronous_standby_names	sighup	Replication / Master Server	STRING				Number of synchronous standbys and list of names of potential synchronous ones.	
syslog_facility	sighup	Reporting and Logging / Where to Log	ENUM	local0			Sets the syslog "facility" to be used when syslog enabled.	
syslog_ident	sighup	Reporting and Logging / Where to Log	STRING	postgres			Sets the program name used to identify PostgreSQL messages in syslog.	
syslog_sequence_numbers	sighup	Reporting and Logging / Where to Log	BOOLEAN	FALSE			Add sequence number to syslog messages to avoid duplicate suppression.	
syslog_split_messages	sighup	Reporting and Logging / Where to Log	BOOLEAN	FALSE			Split messages sent to syslog by lines and to fit into 1024 bytes.	
tcp_keepalives_count	user	Client Connection Defaults / Other Defaults	INTEGER	0	0	2147483647	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.
tcp_keepalives_idle	user	Client Connection Defaults / Other Defaults	INTEGER	0	0	2147483647	Time between issuing TCP keepalives.	A value of 0 uses the system default.
tcp_keepalives_interval	user	Client Connection Defaults / Other Defaults	INTEGER	0	0	2147483647	Time between TCP keepalive retransmits.	A value of 0 uses the system default.
temp_buffers	user	Resource Usage / Memory	INTEGER	0	100	1073741823	Sets the maximum number of temporary buffers used by each session.	
temp_file_limit	superuser	Resource Usage / Disk	INTEGER	0	-1	2147483647	Limits the total size of all temporary files used by each process.	-1 means no limit.
temp_tablespaces	user	Client Connection Defaults / Statement Behavior	STRING				Sets the tablespace(s) to use for temporary tables and sort files.	
TimeZone	user	Client Connection Defaults / Locale and Formatting	STRING	GMT			Sets the time zone for displaying and interpreting time stamps.	
timezone_abbreviations	user	Client Connection Defaults / Locale and Formatting	STRING				Selects a file of time zone abbreviations.	
trace_recovery_messages	sighup	Developer Options	ENUM	log			Enables logging of recovery-related debugging information.	Each level includes all the levels that follow it. The later the level, the fewer messages are sent.
track_activities	superuser	Statistics / Query and Index Statistics Collector	BOOLEAN	FALSE			Collects information about executing commands.	Enables the collection of information on the currently executing command of each session, along with the time at which that command began execution.
track_activity_query_size	postmaster	Resource Usage / Memory	INTEGER	0	100	102400	Sets the size reserved for pg_stat_activity.query, in bytes.	
track_commit_timestamp	postmaster	Replication	BOOLEAN	FALSE			Collects transaction commit time.	
track_counts	superuser	Statistics / Query and Index Statistics Collector	BOOLEAN	FALSE			Collects statistics on database activity.	
track_functions	superuser	Statistics / Query and Index Statistics Collector	ENUM	none			Collects function-level statistics on database activity.	
track_io_timing	superuser	Statistics / Query and Index Statistics Collector	BOOLEAN	FALSE			Collects timing statistics for database I/O activity.	
transform_null_equals	user	Version and Platform Compatibility / Other Platforms and Clients	BOOLEAN	FALSE			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).
unix_socket_directories	postmaster	Connections and Authentication / Connection Settings	STRING	/jet/run/postgresql, /jet/run/postgresql			Sets the directories where Unix-domain sockets will be created.	
unix_socket_group	postmaster	Connections and Authentication / Connection Settings	STRING				Sets the owning group of the Unix-domain socket.	The owning user of the socket is always the user that starts the server.
unix_socket_permissions	postmaster	Connections and Authentication / Connection Settings	INTEGER	0	0	511	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 a 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).)
update_process_title	superuser	Process Title	BOOLEAN	FALSE			Updates the process title to show the active SQL command.	Enables updating of the process title every time a new SQL command is received by the server.
vacuum_cost_delay	user	Resource Usage / Cost-Based Vacuum Delay	INTEGER	0	0	100	Vacuum cost delay in milliseconds.	
vacuum_cost_limit	user	Resource Usage / Cost-Based Vacuum Delay	INTEGER	0	1	10000	Vacuum cost amount available before napping.	
vacuum_cost_page_dirty	user	Resource Usage / Cost-Based Vacuum Delay	INTEGER	0	0	10000	Vacuum cost for a page dirtied by vacuum.	
vacuum_cost_page_hit	user	Resource Usage / Cost-Based Vacuum Delay	INTEGER	0	0	10000	Vacuum cost for a page found in the buffer cache.	
vacuum_cost_page_miss	user	Resource Usage / Cost-Based Vacuum Delay	INTEGER	0	0	10000	Vacuum cost for a page not found in the buffer cache.	
vacuum_defer_cleanup_age	sighup	Replication / Master Server	INTEGER	0	0	1000000	Number of transactions by which VACUUM and HOT cleanup should be deferred, if any.	
vacuum_freeze_min_age	user	Client Connection Defaults / Statement Behavior	INTEGER	0	0	1000000000	Minimum age at which VACUUM should freeze a table row.	
vacuum_freeze_table_age	user	Client Connection Defaults / Statement Behavior	INTEGER	0	0	2000000000	Age at which VACUUM should scan whole table to freeze tuples.	
vacuum_multixact_freeze_min_age	user	Client Connection Defaults / Statement Behavior	INTEGER	0	0	1000000000	Minimum age at which VACUUM should freeze a MultiXactId in a table row.	
vacuum_multixact_freeze_table_age	user	Client Connection Defaults / Statement Behavior	INTEGER	0	0	2000000000	Multixact age at which VACUUM should scan whole table to freeze tuples.	
wal_buffers	postmaster	Write-Ahead Log / Settings	INTEGER	0	-1	262143	Sets the number of disk-page buffers in shared memory for WAL.	
wal_compression	superuser	Write-Ahead Log / Settings	BOOLEAN	FALSE			Compresses full-page writes written in WAL file.	
wal_keep_segments	sighup	Replication / Sending Servers	INTEGER	0	0	2147483647	Sets the number of WAL files held for standby servers.	
wal_level	postmaster	Write-Ahead Log / Settings	ENUM	minimal			Set the level of information written to the WAL.	
wal_log_hints	postmaster	Write-Ahead Log / Settings	BOOLEAN	FALSE			Writes full pages to WAL when first modified after a checkpoint, even for a non-critical modifications.	
wal_receiver_status_interval	sighup	Replication / Standby Servers	INTEGER	0	0	2147483	Sets the maximum interval between WAL receiver status reports to the primary.	
wal_receiver_timeout	sighup	Replication / Standby Servers	INTEGER	0	0	2147483647	Sets the maximum wait time to receive data from the primary.	
wal_retrieve_retry_interval	sighup	Replication / Standby Servers	INTEGER	0	1	2147483647	Sets the time to wait before retrying to retrieve WAL after a failed attempt.	
wal_sender_timeout	sighup	Replication / Sending Servers	INTEGER	0	0	2147483647	Sets the maximum time to wait for WAL replication.	
wal_sync_method	sighup	Write-Ahead Log / Settings	ENUM	fdatasync			Selects the method used for forcing WAL updates to disk.	
wal_writer_delay	sighup	Write-Ahead Log / Settings	INTEGER	0	1	10000	Time between WAL flushes performed in the WAL writer.	
wal_writer_flush_after	sighup	Write-Ahead Log / Settings	INTEGER	0	0	2147483647	Amount of WAL written out by WAL writer that triggers a flush.	
work_mem	user	Resource Usage / Memory	INTEGER	0	64	2147483647	Sets the maximum memory to be used for query workspaces.	This much memory can be used by each internal sort operation and hash table before switching to temporary disk files.
xmlbinary	user	Client Connection Defaults / Statement Behavior	ENUM	base64			Sets how binary values are to be encoded in XML.	
xmloption	user	Client Connection Defaults / Statement Behavior	ENUM	content			Sets whether XML data in implicit parsing and serialization operations is to be considered as documents or content fragments.