这篇文章主要介绍了GP参数修改gpconfig的使用相关。 本文分为以下几个部分：
- GPDB介绍
- gpconfig使用
1.GPDB介绍
由于GPDB是分布式数据库，其参数文件分布于各个节点，如果每次参数修改都要到每个节点的配置文件上进行操作，那么效率太低，使得系统可维护性变差。所以，从4.0开始GREENPLUM就提供工具gpconfig，通过主节点就可以对所有节点的参数文件进行批量修改，极大方便了DBA的工作。
2.gpconfig使用
2.1 修改参数
比如要修改最大连接数的参数，可以以gpadmin用户登录master，执行如下命令:
gpconfig -c max_connection -v 750 -m 150
说明如下：
- (1) -c 指定要参数;
- (2) -v 指定segment 参数的设置值，如果没有-m参数，它也指定master上参数的设置，-m 如果希望master参数不同于segment，那么通过该参数独立指定master的参数值。
2.2 查询参数
可以使用指令gpconfig -s 查询参数，例如查看节点的最大连接数：
gpconfig -s max_connections
2.3 注意事项
gpconfig只能在系统启动的情况下调用，所以如果参数修改不合适，导致系统无法启动时，我们可以用下列方法处理:
- 1、先把master的参数修改成正常的值
- 2、gpstart -m 仅启动master进入管理模式
- 3、gpconfig -r <参数> -- 把参数重置成默认值
- 4、gpstop -a -r -M fast
3.参考地址
【1】. https://yq.aliyun.com/articles/145445
4.greenplum6.2参数列表
name | setting | description
------------------------------------------------------+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------
application_name | psql | Sets the application name to be reported in statistics and logs.
archive_mode | off | Allows archiving of WAL files using archive_command.
array_nulls | on | Enable input of NULL elements in arrays.
authentication_timeout | 1min | Sets the maximum allowed time to complete client authentication.
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_work_mem | -1 | Sets the maximum memory to be used by each autovacuum worker process.
backslash_quote | safe_encoding | Sets whether "\'" is allowed in string literals.
block_size | 32768 | 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.
client_encoding | UTF8 | Sets the client's character set encoding.
client_min_messages | notice | Sets the message levels that are sent to the client.
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).
create_restartpoint_on_ckpt_record_replay | off | create a restartpoint only on mirror immediately after replaying a checkpoint record.
cursor_tuple_fraction | 1 | Sets the planner's estimate of the fraction of a cursor's rows that will be retrieved.
data_checksums | on | Shows whether data checksums are turned on for this cluster.
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 | Turns on various assertion checks.
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_prelim_plan | off | Prints the preliminary execution plan to server log.
debug_print_rewritten | off | Logs each query's rewritten parse tree.
debug_print_slice_table | off | Prints the slice table to server log.
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.
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 | 16GB | 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_groupagg | on | Enables the planner's use of grouping aggregation 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 | off | Enables the planner's use of merge join plans.
enable_nestloop | off | Enables the planner's use of nested-loop join plans.
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.
explain_memory_verbosity | suppress | Experimental feature: show memory account usage in EXPLAIN ANALYZE.
extra_float_digits | 0 | Sets the number of digits displayed for floating-point values.
from_collapse_limit | 20 | Sets the FROM-list size beyond which subqueries are not collapsed.
geqo_seed | 1 | Unused. Syntax check only for PostgreSQL compatibility.
gin_fuzzy_search_limit | 0 | Sets the maximum allowed result for exact search by GIN.
gp_adjust_selectivity_for_outerjoins | on | Adjust selectivity of null tests over outer joins.
gp_appendonly_compaction_threshold | 10 | Threshold of the ratio of dirty data in a segment file over which the file will be compacted during lazy vacuum.
gp_autostats_mode | on_no_stats | Sets the autostats mode.
gp_autostats_mode_in_functions | none | Sets the autostats mode for statements in procedural language functions.
gp_autostats_on_change_threshold | 2147483647 | Threshold for number of tuples added to table by CTAS or Insert-to to trigger autostats in on_change mode. See gp_autostats_mode.
gp_cached_segworkers_threshold | 5 | Sets the maximum number of segment workers to cache between statements.
gp_command_count | 1 | Shows the number of commands received from the client in this session.
gp_connection_send_timeout | 3600 | Timeout for sending data to unresponsive clients (seconds)
gp_contentid | -1 | The contentid used by this server.
gp_create_table_random_default_distribution | off | Set the default distribution of a table to RANDOM.
gp_dbid | 1 | The dbid used by this server.
gp_debug_linger | 0 | Number of seconds for QD/QE process to linger upon fatal internal error.
gp_default_storage_options | appendonly=false,blocksize=32768,compresstype=none,checksum=true,orientation=row | default options for appendonly storage.
gp_dynamic_partition_pruning | on | This guc enables plans that can dynamically eliminate scanning of partitions.
gp_enable_agg_distinct | on | Enable 2-phase aggregation to compute a single distinct-qualified aggregate.
gp_enable_agg_distinct_pruning | on | Enable 3-phase aggregation and join to compute distinct-qualified aggregates.
gp_enable_direct_dispatch | on | Enable dispatch for single-row-insert targetted mirror-pairs.
gp_enable_exchange_default_partition | off | Allow DDL that will exchange default partitions.
gp_enable_fast_sri | on | Enable single-slice single-row inserts.
gp_enable_global_deadlock_detector | off | Enables the Global Deadlock Detector.
gp_enable_gpperfmon | off | Enable gpperfmon monitoring.
gp_enable_groupext_distinct_gather | on | Enable gathering data to a single node to compute distinct-qualified aggregates on grouping extention queries.
gp_enable_groupext_distinct_pruning | on | Enable 3-phase aggregation and join to compute distinct-qualified aggregates on grouping extention queries.
gp_enable_minmax_optimization | on | Enables the planner's use of index scans with limit to implement MIN/MAX.
gp_enable_multiphase_agg | on | Enables the planner's use of two- or three-stage parallel aggregation plans.
gp_enable_predicate_propagation | on | When two expressions are equivalent (such as with equijoined keys) then the planner applies predicates on one expression to the oth
er expression.
gp_enable_preunique | on | Enable 2-phase duplicate removal.
gp_enable_query_metrics | off | Enable all query metrics collection.
gp_enable_relsize_collection | off | This guc enables relsize collection when stats are not present. If disabled and stats are not present a default value is used.
gp_enable_sort_distinct | on | Enable duplicate removal to be performed while sorting.
gp_enable_sort_limit | on | Enable LIMIT operation to be performed while sorting.
gp_external_enable_exec | on | Enable selecting from an external table with an EXECUTE clause.
gp_external_enable_filter_pushdown | on | Enable passing of query constraints to external table providers
gp_external_max_segs | 64 | Maximum number of segments that connect to a single gpfdist URL.
gp_fts_mark_mirror_down_grace_period | 30s | Time (in seconds) allowed to mirror after disconnection, to reconnect before being marked as down in configuration by FTS.
gp_fts_probe_interval | 1min | A complete probe of all segments starts each time a timer with this period expires.
gp_fts_probe_retries | 5 | Number of retries for FTS to complete probing a segment.
gp_fts_probe_timeout | 20s | Maximum time (in seconds) allowed for FTS to complete probing a segment.
gp_global_deadlock_detector_period | 2min | Sets the executing period of global deadlock detector backend.
gp_gpperfmon_send_interval | 1 | Interval in seconds between sending messages to gpperfmon.
gp_hashjoin_tuples_per_bucket | 5 | Target density of hashtable used by Hashjoin during execution
gp_initial_bad_row_limit | 1000 | Stops processing when number of the first bad rows exceeding this value
gp_instrument_shmem_size | 5MB | Sets the size of shmem allocated for instrumentation.
gp_interconnect_cache_future_packets | on | Control whether future packets are cached.
gp_interconnect_debug_retry_interval | 10 | Sets the interval by retry times to record a debug message for retry.
gp_interconnect_default_rtt | 20ms | Sets the default rtt (in ms) for UDP interconnect
gp_interconnect_fc_method | loss | Sets the flow control method used for UDP interconnect.
gp_interconnect_min_retries_before_timeout | 100 | Sets the min retries before reporting a transmit timeout in the interconnect.
gp_interconnect_min_rto | 20ms | Sets the min rto (in ms) for UDP interconnect
gp_interconnect_queue_depth | 4 | Sets the maximum size of the receive queue for each connection in the UDP interconnect
gp_interconnect_setup_timeout | 2h | Timeout (in seconds) on interconnect setup that occurs at query start
gp_interconnect_snd_queue_depth | 2 | Sets the maximum size of the send queue for each connection in the UDP interconnect
gp_interconnect_tcp_listener_backlog | 128 | Size of the listening queue for each TCP interconnect socket
gp_interconnect_timer_checking_period | 20ms | Sets the timer checking period (in ms) for UDP interconnect
gp_interconnect_timer_period | 5ms | Sets the timer period (in ms) for UDP interconnect
gp_interconnect_transmit_timeout | 1h | Timeout (in seconds) on interconnect to transmit a packet
gp_interconnect_type | udpifc | Sets the protocol used for inter-node communication.
gp_log_format | csv | Sets the format for log files.
gp_max_local_distributed_cache | 1024 | Sets the number of local-distributed transactions to cache for optimizing visibility processing by backends.
gp_max_packet_size | 8192 | Sets the max packet size for the Interconnect.
gp_max_partition_level | 0 | Sets the maximum number of levels allowed when creating a partitioned table.
gp_max_plan_size | 0 | Sets the maximum size of a plan to be dispatched.
gp_max_slices | 0 | Maximum slices for a single query
gp_motion_cost_per_row | 0 | Sets the planner's estimate of the cost of moving a row between worker processes.
gp_reject_percent_threshold | 300 | Reject limit in percent starts calculating after this number of rows processed
gp_reraise_signal | on | Do we attempt to dump core when a serious problem occurs.
gp_resgroup_memory_policy | eager_free | Sets the policy for memory allocation of queries.
gp_resource_group_bypass | off | If the value is true, the query in this session will not be limited by resource group.
gp_resource_group_cpu_limit | 0.9 | Maximum percentage of CPU resources assigned to a cluster.
gp_resource_group_cpu_priority | 10 | Sets the cpu priority for postgres processes when resource group is enabled.
gp_resource_group_memory_limit | 0.7 | Maximum percentage of memory resources assigned to a cluster.
gp_resource_manager | queue | Sets the type of resource manager.
gp_resqueue_memory_policy | eager_free | Sets the policy for memory allocation of queries.
gp_resqueue_priority | on | Enables priority scheduling.
gp_resqueue_priority_cpucores_per_segment | 4 | Number of processing units associated with a segment.
gp_resqueue_priority_sweeper_interval | 1000 | Frequency (in ms) at which sweeper process re-evaluates CPU shares.
gp_role | dispatch | Sets the role for the session.
gp_safefswritesize | 0 | Minimum FS safe write size.
gp_segment_connect_timeout | 10min | Maximum time (in seconds) allowed for a new worker process to start or a mirror to respond.
gp_segments_for_planner | 0 | If >0, number of segment dbs for the planner to assume in its cost and size estimates.
gp_server_version | 6.2.1 build commit:d90ac1a1b983b913b3950430d4d9e47ee8827fd4 | Shows the Greenplum server version.
gp_server_version_num | 60000 | Shows the Greenplum server version as an integer.
gp_session_id | 314 | Global ID used to uniquely identify a particular session in an Greenplum Database array
gp_set_proc_affinity | off | On postmaster startup, attempt to bind postmaster to a processor
gp_statistics_pullup_from_child_partition | on | This guc enables the planner to utilize statistics from partitions in planning queries on the parent.
gp_statistics_use_fkeys | on | This guc enables the planner to utilize statistics derived from foreign key relationships.
gp_subtrans_warn_limit | 16777216 | Sets the warning limit on number of subtransactions in a transaction.
gp_udp_bufsize_k | 0 | Sets recv buf size of UDP interconnect, for testing.
gp_vmem_idle_resource_timeout | 18s | Sets the time a session can be idle (in milliseconds) before we release gangs on the segment DBs to free resources.
gp_vmem_protect_limit | 8192 | Virtual memory limit (in MB) of Greenplum memory protection.
gp_vmem_protect_segworker_cache_limit | 500 | Max virtual memory limit (in MB) for a segworker to be cachable.
gp_workfile_compression | off | Enables compression of temporary files.
gp_workfile_limit_files_per_query | 100000 | Maximum number of workfiles allowed per query per segment.
gp_workfile_limit_per_query | 0 | Maximum disk space (in KB) used for workfiles per query per segment.
gp_workfile_limit_per_segment | 0 | Maximum disk space (in KB) used for workfiles per segment.
gpperfmon_log_alert_level | none | Specify the log alert level used by gpperfmon.
gpperfmon_port | 8888 | Sets the port number of gpperfmon.
hot_standby | off | 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.
ignore_checksum_failure | off | Continues processing after a checksum failure.
integer_datetimes | on | Datetimes are integer based.
IntervalStyle | postgres | Sets the display format for interval values.
join_collapse_limit | 20 | 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 | FILE:/usr/local/greenplum-db-oss/etc/postgresql/krb5.keytab | 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_autostats | off | Logs details of auto-stats issued ANALYZEs.
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_disconnections | off | Logs end of a session, including duration.
log_dispatch_stats | off | Writes dispatcher performance statistics to the server log.
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_hostname | off | Logs the host name in the connection logs.
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_rotation_age | 1d | Automatic log file rotation will occur after N minutes.
log_rotation_size | 1GB | Automatic log file rotation will occur after N kilobytes.
log_statement | all | 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 | PRC | 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 | on | 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_appendonly_tables | 10000 | Maximum number of different (unrelated) append only tables that can participate in writing data concurrently.
max_connections | 250 | 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 | 128 | Sets the maximum number of locks per transaction.
max_pred_locks_per_transaction | 64 | Sets the maximum number of predicate locks per transaction.
max_prepared_transactions | 250 | Sets the maximum number of simultaneously prepared transactions.
max_replication_slots | 10 | Sets the maximum number of simultaneously defined replication slots.
max_resource_portals_per_transaction | 64 | Maximum number of resource queues.
max_resource_queues | 9 | Maximum number of resource queues.
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_statement_mem | 2000MB | Sets the maximum value for statement_mem setting.
max_wal_senders | 10 | Sets the maximum number of simultaneously running WAL sender processes.
max_worker_processes | 14 | Maximum number of concurrent worker processes.
memory_spill_ratio | 20 | Sets the memory_spill_ratio for resource group.
optimizer | on | Enable Pivotal Query Optimizer.
optimizer_analyze_root_partition | on | Enable statistics collection on root partitions during ANALYZE
optimizer_control | on | Allow/disallow turning the optimizer on or off.
optimizer_enable_associativity | off | Enables Join Associativity in optimizer
optimizer_join_arity_for_associativity_commutativity | 18 | Maximum number of children n-ary-join have without disabling commutativity and associativity transform
optimizer_join_order | exhaustive | Set optimizer join heuristic model.
optimizer_join_order_threshold | 10 | Maximum number of join children to use dynamic programming based join ordering algorithm.
optimizer_mdcache_size | 16MB | Sets the size of MDCache.
optimizer_metadata_caching | on | This guc enables the optimizer to cache and reuse metadata.
optimizer_minidump | onerror | Generate optimizer minidump.
optimizer_parallel_union | off | Enable parallel execution for UNION/UNION ALL queries.
password_encryption | on | Encrypt passwords.
password_hash_algorithm | MD5 | The cryptograph hash algorithm to apply to passwords before storing them.
pljava_classpath | | classpath used by the the JVM
pljava_classpath_insecure | off | Allow pljava_classpath to be set by user per session
pljava_release_lingering_savepoints | off | If true, lingering savepoints will be released on function exit; if false, they will be rolled back
pljava_statement_cache_size | 0 | Size of the prepared statement MRU cache
pljava_vmoptions | | Options sent to the JVM when it is created
port | 5432 | Sets the TCP port the server listens on.
quote_all_identifiers | off | When generating SQL fragments, quote all identifiers.
random_page_cost | 100 | Sets the planner's estimate of the cost of a nonsequentially fetched disk page.
readable_external_table_timeout | 0 | Cancel the query if no data read within N seconds.
repl_catchup_within_range | 1 | Sets the maximum number of xlog segments allowed to lag when the backends can start blocking despite the WAL sender being in catchu
p phase. (Master Mirroring)
resource_cleanup_gangs_on_wait | on | Enable idle gang cleanup before resource lockwait.
resource_scheduler | on | Enable resource scheduling.
resource_select_only | off | Enable resource locking of SELECT only.
restart_after_crash | on | Reinitialize server after backend crash.
runaway_detector_activation_percent | 90 | The runaway detector activates if the used vmem exceeds this percentage of the vmem quota. Set to 100 to disable runaway detection.
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 | 9.4.24 | Shows the server version.
server_version_num | 90424 | 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 | 125MB | 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_ecdh_curve | prime256v1 | Sets the curve to use for ECDH.
ssl_key_file | server.key | Location of the SSL server private key file.
ssl_prefer_server_ciphers | on | Give priority to server ciphersuite order.
standard_conforming_strings | on | Causes '...' strings to treat backslashes literally.
statement_mem | 125MB | Sets the memory to be reserved for a statement.
statement_timeout | 0 | Sets the maximum allowed duration of any statement.
stats_queue_level | off | Collects resource queue-level statistics on database activity.
superuser_reserved_connections | 3 | Sets the number of connection slots reserved for superusers (including reserved FTS connections).
synchronize_seqscans | on | Enable synchronized sequential scans.
synchronous_commit | on | Sets the current transaction's synchronization level.
synchronous_standby_names | | List of names of potential synchronous standbys.
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 | 32MB | 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 session.
temp_tablespaces | | Sets the tablespace(s) to use for temporary tables and sort files.
TimeZone | PRC | Sets the time zone for displaying and interpreting time stamps.
timezone_abbreviations | Default | Selects a file of time zone abbreviations.
trace_recovery_messages | log | Enables logging of recovery-related debugging information.
track_activities | on | Collects information about executing commands.
track_activity_query_size | 1024 | Sets the size reserved for pg_stat_activity.query, in bytes.
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 | /tmp | 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_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 | 32768 | Shows the block size in the write ahead log.
wal_buffers | 4000kB | Sets the number of disk-page buffers in shared memory for WAL.
wal_keep_segments | 5 | Sets the number of WAL files held for standby servers.
wal_level | archive | 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_segment_size | 64MB | Shows the number of pages per write ahead log segment.
wal_sender_timeout | 1min | Sets the maximum time to wait for WAL replication.
wal_writer_delay | 200ms | WAL writer sleep time between WAL flushes.
work_mem | 32MB | Sets the maximum memory to be used for query workspaces.
writable_external_table_bufsize | 64kB | Buffer size in kilobytes for writable external table before writing data to gpfdist.
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.
(324 rows)
