This page lists the database flags that AlloyDB supports.
You use database flags for many operations, including adjusting PostgreSQL parameters, adjusting options, and configuring and tuning instances.
In some cases, setting one flag may require that you set another flag to fully enable the desired functionality.
When you set, remove, or modify a flag for an instance, the instance might be restarted. The flag value is then persisted for the instance until you remove it.
Flags not mentioned below are not supported.
A | C | D | E | F | G | H | I | J | L | M | O | P | R | S | T | V | W
| AlloyDB Flag | Type Acceptable Values and Notes |
Restart Required? |
|---|---|---|
| alloydb.enable_auto_explain | booleanon | off |
Yes |
| alloydb.enable_pg_bigm | booleanon | off |
Yes |
| alloydb.enable_pg_cron | booleanon | off |
Yes |
| alloydb.enable_pg_hint_plan | booleanon | off |
Yes |
| alloydb.enable_pgaudit | booleanon | off |
Yes |
| alloydb.enable_pglogical | booleanon | off |
Yes |
| alloydb.logical_decoding | booleanon | off |
Yes |
| alloydb.pg_shadow_select_role | string |
No |
| auto_explain.log_analyze | booleanon | off |
No |
| auto_explain.log_buffers | booleanon | off |
No |
| auto_explain.log_format | enumerationtext | xml | json | yaml |
No |
| auto_explain.log_level | enumerationdebug5 | debug4 | debug3 | debug2 | debug1 | debug | info | notice | warning | log |
No |
| auto_explain.log_min_duration | integer-1 ... 2147483647 |
No |
| auto_explain.log_nested_statements | booleanon | off |
No |
| auto_explain.log_settings | booleanon | off |
No |
| auto_explain.log_timing | booleanon | off |
No |
| auto_explain.log_triggers | booleanon | off |
No |
| auto_explain.log_verbose | booleanon | off |
No |
| auto_explain.log_wal | booleanon | off |
No |
| auto_explain.sample_rate | float0 ... 1 |
No |
| autovacuum | booleanon | off |
No |
| autovacuum_analyze_scale_factor | float0 ... 100 |
No |
| autovacuum_analyze_threshold | integer0 ... 2147483647 |
No |
| autovacuum_freeze_max_age | integer100000 ... 2000000000 |
Yes |
| autovacuum_max_workers | integer1 ... 262143 |
Yes |
| autovacuum_multixact_freeze_max_age | integer10000 ... 2000000000 |
Yes |
| autovacuum_naptime | integer1 ... 2147483 |
No |
| autovacuum_vacuum_cost_delay | integer-1 ... 100 |
No |
| autovacuum_vacuum_cost_limit | integer-1 ... 10000 |
No |
| autovacuum_vacuum_scale_factor | float0 ... 100 |
No |
| autovacuum_vacuum_threshold | integer0 ... 2147483647 |
No |
| autovacuum_work_mem | integer-1 ... 2147483647Unit is kB. |
No |
| checkpoint_completion_target | float0 ... 1 |
No |
| checkpoint_timeout | integer30 ... 86400Unit is s. |
No |
| checkpoint_warning | integer0 ... 2147483647Unit is s. |
No |
| commit_delay | integer0 ... 100000 |
No |
| commit_siblings | integer0 ... 1000 |
No |
| constraint_exclusion | enumerationpartition | on | off |
No |
| cpu_index_tuple_cost | float0 ... 3.4028235e+38 |
No |
| cpu_operator_cost | float0 ... 3.4028235e+38 |
No |
| cpu_tuple_cost | float0 ... 3.4028235e+38 |
No |
| cron.database_name | string |
Yes |
| cron.log_min_messages | enumerationdebug5 | debug4 | debug3 | debug2 | debug1 | debug | info | notice | warning | error | log | fatal | panic |
No |
| cron.log_run | booleanon | off |
Yes |
| cron.log_statement | booleanon | off |
Yes |
| cron.max_running_jobs | integer0 |
Yes |
| cursor_tuple_fraction | float0 ... 1 |
No |
| deadlock_timeout | integer1 ... 2147483647Unit is ms. |
No |
| default_statistics_target | integer1 ... 10000 |
No |
| default_tablespace | string |
No |
| default_transaction_deferrable | booleanon | off |
No |
| default_transaction_isolation | enumerationserializable | 'repeatable read' | 'read committed' | 'read uncommitted'Single quotes are required around enumeration strings that contain spaces. |
No |
| effective_cache_size | integer1 ... 2147483647Unit is blocks. |
No |
| enable_bitmapscan | booleanon | off |
No |
| enable_hashagg | booleanon | off |
No |
| enable_hashjoin | booleanon | off |
No |
| enable_indexonlyscan | booleanon | off |
No |
| enable_indexscan | booleanon | off |
No |
| enable_material | booleanon | off |
No |
| enable_mergejoin | booleanon | off |
No |
| enable_nestloop | booleanon | off |
No |
| enable_seqscan | booleanon | off |
No |
| enable_sort | booleanon | off |
No |
| enable_tidscan | booleanon | off |
No |
| force_parallel_mode | enumerationoff | on | regress |
No |
| from_collapse_limit | integer1 ... 2147483647 |
No |
| geqo | booleanon | off |
No |
| geqo_effort | integer1 ... 10 |
No |
| geqo_generations | integer0 ... 2147483647 |
No |
| geqo_pool_size | integer0 ... 2147483647 |
No |
| geqo_seed | float0 ... 1 |
No |
| geqo_selection_bias | float1.5 ... 2 |
No |
| geqo_threshold | integer2 ... 2147483647 |
No |
| gin_fuzzy_search_limit | integer0 ... 2147483647 |
No |
| gin_pending_list_limit | integer64 ... 2147483647Unit is kB. |
No |
| google_columnar_engine.column_set_stat_statements_max_memory_size | integer1048576 ... 2147483647 |
Yes |
| google_columnar_engine.memory_size_in_mb | integer128 ... 2147483647 |
Yes |
| google_columnar_engine.enable_columnar_recommendation | booleanon | off |
No |
| google_columnar_engine.enable_columnar_scan | booleanon | off |
No |
| google_columnar_engine.enabled | booleanon | off |
Yes |
| google_columnar_engine.estimate_relation_size_sampling_percentage | float0.0 ... 100.0 |
No |
| google_columnar_engine.hypothetical_config_max_memory_size | integer1048576 ... 2147483647 |
Yes |
| google_columnar_engine.maintenance_cpu_percentage | integer0 ... 100 |
No |
| google_columnar_engine.max_num_pending_whatif_analysis | integer1 ... 2147483647 |
Yes |
| google_columnar_engine.max_parallel_workers_per_job | integer0 ... 262143 |
No |
| google_columnar_engine.max_sampled_query_length | integer1 ... 2147483647 |
Yes |
| google_columnar_engine.query_sampling_percentage | float0 ... 100 |
No |
| google_columnar_engine.refresh_threshold_percentage | integer-1 ... 100 |
No |
| google_columnar_engine.refresh_threshold_scan_count | integer0 ... 2147483647 |
No |
| google_columnar_engine.relations | string |
No |
| google_columnar_engine.scan_mode | integer0 ... 2 |
No |
| hot_standby_feedback | booleanon | off |
No |
| idle_in_transaction_session_timeout | integer0 ... 2147483647Unit is ms. |
No |
| join_collapse_limit | integer1 ... 2147483647 |
No |
| lock_timeout | integer0 ... 2147483647Unit is ms. |
No |
| log_autovacuum_min_duration | integer-1 ... 2147483647 |
No |
| log_checkpoints | booleanon | off |
No |
| log_connections | booleanon | off |
No |
| log_disconnections | booleanon | off |
No |
| log_duration | booleanon | off |
No |
| log_error_verbosity | enumerationterse | default | verbose |
No |
| log_executor_stats | booleanon | off |
No |
| log_hostname | booleanon | off |
No |
| log_lock_waits | booleanon | off |
No |
| log_min_duration_statement | integer-1 ... 2147483647Unit is ms. |
No |
| log_min_error_statement | enumerationdebug5 | debug4 | debug3 | debug2 | debug1 | info | notice | warning | error | log | fatal | panic |
No |
| log_min_messages | enumerationdebug5 | debug4 | debug3 | debug2 | debug1 | info | notice | warning | error | log | fatal | panic |
No |
| log_parser_stats | booleanon | off |
No |
| log_planner_stats | booleanon | off |
No |
| log_replication_commands | booleanon | off |
No |
| log_statement | enumerationnone | ddl | mod | all |
No |
| log_statement_stats | booleanon | off |
No |
| log_temp_files | integer-1 ... 2147483647Unit is kB. |
No |
| maintenance_work_mem | integer1024 ... 2147483647Unit is kB. |
No |
| max_connections | integer1000 ... 240000This flag's value on a read pool instance must be greater than or equal to the value on the primary instance. Also, the minimum provides at most 970 non-superuser connections, as the superuser_reserved_connections flag reserves 30 connections. |
Yes |
| max_locks_per_transaction | integer10 ... 2147483647This flag's value on a read pool instance must be greater than or equal to the value on the primary instance. |
Yes |
| max_logical_replication_workers | integer4 ... 8192Maxiumum value is dependent on instance memory and limited to max_worker_processes. |
Yes |
| max_parallel_workers | integer0 ... 1024Maximum value is dependent on instance memory. |
No |
| max_parallel_workers_per_gather | integer0 ... 1024Maximum value is dependent on instance memory. |
No |
| max_pred_locks_per_page | integer0 ... 2147483647 |
Yes |
| max_pred_locks_per_relation | integer-2147483648 ... 2147483647 |
Yes |
| max_pred_locks_per_transaction | integer10 ... 1048576 |
Yes |
| max_prepared_transactions | integer0 ... 262143This flag's value on a read pool instance must be greater than or equal to the value on the primary instance. |
Yes |
| max_replication_slots | integer10 ... 8192Maximum value is dependent on instance memory. |
Yes |
| max_standby_archive_delay | integer-1 ... 2147483647Unit is ms. |
No |
| max_standby_streaming_delay | integer-1 ... 2147483647Unit is ms. |
No |
| max_sync_workers_per_subscription | integer2 ... 64Limited by max_logical_replication_workers. |
No |
| max_wal_senders | integer10 ... 8192This flag's value on a read pool instance must be greater than or equal to the value on the primary instance. Also, maximum value is dependent on instance memory. |
Yes |
| max_wal_size | integer32 ... 2147483647Unit is MB. Must be at least twice wal_segment_size. |
No |
| max_worker_processes | integer8 ... 4096This flag's value on a read pool instance must be greater than or equal to the value on the primary instance. Also, maximum value is dependent on instance memory. |
Yes |
| min_parallel_relation_size | integer0 ... 715827882Unit is 8kB. |
No |
| min_wal_size | integer32 ... 2147483647Unit is MB. Must be at least twice wal_segment_size. |
No |
| old_snapshot_threshold | integer-1 ... 86400Unit is min. |
Yes |
| parallel_setup_cost | float0 ... 3.4028235e+38 |
No |
| parallel_tuple_cost | float0 ... 3.4028235e+38 |
No |
| password_encryption | enumerationmd5 | scram-sha-256 |
No |
| pg_bigm.enable_recheck | booleanon | off |
No |
| pg_bigm.gin_key_limit | integer0 ... 2147483647 |
No |
| pg_bigm.similarity_limit | float0 ... 1 |
No |
| pg_hint_plan.debug_print | enumerationoff | on | detailed | verbose | 0 | 1 | 2 | 3 | no | yes | false | true |
No |
| pg_hint_plan.enable_hint | booleanon | off |
No |
| pg_hint_plan.enable_hint_table | booleanon | off |
No |
| pg_hint_plan.message_level | enumerationdebug5 | debug4 | debug3 | debug2 | debug1 | debug | info | notice | warning | error | log |
No |
| pg_hint_plan.parse_messages | enumerationdebug5 | debug4 | debug3 | debug2 | debug1 | debug | info | notice | warning | error | log |
No |
| pg_stat_statements.max | integer100 ... 2147483647 |
Yes |
| pg_stat_statements.save | booleanon | off |
No |
| pg_stat_statements.track | enumerationnone | top | all |
No |
| pg_stat_statements.track_utility | booleanon | off |
No |
| pgaudit.log | enumerationread | write | function | role | ddl | misc | misc_set | all | none | -read | -write | -function | -role | -ddl | -misc | -misc_set | -all | -none |
No |
| pgaudit.log_catalog | booleanon | off |
No |
| pgaudit.log_client | booleanon | off |
No |
| pgaudit.log_level | enumerationdebug | debug5 | debug4 | debug3 | debug2 | debug1 | info | notice | warning | log |
No |
| pgaudit.log_parameter | booleanon | off |
No |
| pgaudit.log_relation | booleanon | off |
No |
| pgaudit.log_statement_once | booleanon | off |
No |
| pgaudit.role | string |
No |
| pglogical.batch_inserts | booleanon | off |
Yes |
| pglogical.conflict_log_level | enumerationdebug5 | debug4 | debug3 | debug2 | debug1 | info | notice | warning | error | log | fatal | panic |
No |
| pglogical.conflict_resolution | enumerationerror | apply_remote | keep_local | last_update_wins | first_update_wins |
No |
| pglogical.extra_connection_options | string |
No |
| pglogical.synchronous_commit | booleanon | off |
Yes |
| pglogical.use_spi | booleanon | off |
Yes |
| random_page_cost | float0 ... 3.4028235e+38 |
No |
| replacement_sort_tuples | integer0 ... 2147483647 |
No |
| shared_buffers | integer16 ... 1073741823Unit is blocks. |
Yes |
| ssl_max_protocol_version | enumerationTLSv1 | TLSv1.1 | TLSv1.2 | TLSv1.3 |
No |
| ssl_min_protocol_version | enumerationTLSv1 | TLSv1.1 | TLSv1.2 | TLSv1.3 |
No |
| standard_conforming_strings | booleanon | off |
No |
| statement_timeout | integer0 ... 2147483647Unit is ms. |
No |
| synchronize_seqscans | booleanon | off |
No |
| tcp_keepalives_count | integer0 ... 2147483647 |
No |
| tcp_keepalives_idle | integer0 ... 2147483647 |
No |
| tcp_keepalives_interval | integer0 ... 2147483647 |
No |
| temp_buffers | integer100 ... 1073741823Unit is 8kB. |
No |
| temp_file_limit | integer1048576 ... 2147483647Unit is kB. |
No |
| trace_notify | booleanon | off |
No |
| trace_recovery_messages | enumerationdebug5 | debug4 | debug3 | debug2 | debug1 | log | notice | warning | error |
No |
| trace_sort | booleanon | off |
No |
| track_activities | booleanon | off |
No |
| track_activity_query_size | integer100 ... 102400 |
Yes |
| track_commit_timestamp | booleanon | off |
Yes |
| track_counts | booleanon | off |
No |
| track_functions | enumerationnone | pl | all |
No |
| track_io_timing | booleanon | off |
No |
| vacuum_cost_delay | integer0 ... 100Unit is ms. |
No |
| vacuum_cost_limit | integer1 ... 10000 |
No |
| vacuum_freeze_min_age | integer0 ... 1000000000 |
No |
| vacuum_freeze_table_age | integer0 ... 2000000000 |
No |
| vacuum_multixact_freeze_min_age | integer0 ... 1000000000 |
No |
| vacuum_multixact_freeze_table_age | integer0 ... 2000000000 |
No |
| wal_buffers | integer-1 ... 262143Unit is blocks. |
Yes |
| work_mem | integer64 ... 2147483647Unit is kB. |
No |