Supported database flags

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This page lists the database flags that AlloyDB for PostgreSQL supports.

You use database flags for many operations, including adjusting PostgreSQL parameters, adjusting options, and configuring and tuning instances.

For more information about setting database flags in AlloyDB, see Configure an instance's database flags.

For more information about how to use each flag listed in the following table, click the name of the flag.

The table's second and third columns contain additional information about each flag:

  • In the Instance restarts column, Yes indicates that AlloyDB restarts an instance whenever you set, remove, or modify this flag on that instance. The flag's value persists for the instance until you modify it again.

  • In the Read pool restrictions column, Yes indicates the following restrictions on how you can use the flag:

    • Before setting this flag on your cluster's primary instance, set the flag on each of your cluster's read pool instances.

    • If the primary instance has this flag set, then the value of this flag on any read pool instance must be equal to or greater than the primary instance's value for this flag.

A | C | D | E | F | G | H | I | J | L | M | O | P | R | S | T | V | W

AlloyDB flag Instance restarts Read pool restrictions
alloydb.enable_auto_explain Yes No
alloydb.enable_pg_bigm Yes No
alloydb.enable_pg_cron Yes No
alloydb.enable_pg_hint_plan Yes No
alloydb.enable_pgaudit Yes No
alloydb.enable_pglogical Yes No
alloydb.logical_decoding Yes No
alloydb.pg_shadow_select_role No No
auto_explain.log_analyze No No
auto_explain.log_buffers No No
auto_explain.log_format No No
auto_explain.log_level No No
auto_explain.log_min_duration No No
auto_explain.log_nested_statements No No
auto_explain.log_settings No No
auto_explain.log_timing No No
auto_explain.log_triggers No No
auto_explain.log_verbose No No
auto_explain.log_wal No No
auto_explain.sample_rate No No
autovacuum No No
autovacuum_analyze_scale_factor No No
autovacuum_analyze_threshold No No
autovacuum_freeze_max_age Yes No
autovacuum_max_workers Yes No
autovacuum_multixact_freeze_max_age Yes No
autovacuum_naptime No No
autovacuum_vacuum_cost_delay No No
autovacuum_vacuum_cost_limit No No
autovacuum_vacuum_scale_factor No No
autovacuum_vacuum_threshold No No
autovacuum_work_mem No No
checkpoint_completion_target No No
checkpoint_timeout No No
checkpoint_warning No No
commit_delay No No
commit_siblings No No
constraint_exclusion No No
cpu_index_tuple_cost No No
cpu_operator_cost No No
cpu_tuple_cost No No
cron.database_name Yes No
cron.log_min_messages No No
cron.log_run Yes No
cron.log_statement Yes No
cron.max_running_jobs Yes No
cursor_tuple_fraction No No
deadlock_timeout No No
default_statistics_target No No
default_tablespace No No
default_transaction_deferrable No No
default_transaction_isolation No No
effective_cache_size No No
enable_bitmapscan No No
enable_hashagg No No
enable_hashjoin No No
enable_indexonlyscan No No
enable_indexscan No No
enable_material No No
enable_mergejoin No No
enable_nestloop No No
enable_seqscan No No
enable_sort No No
enable_tidscan No No
force_parallel_mode No No
from_collapse_limit No No
geqo No No
geqo_effort No No
geqo_generations No No
geqo_pool_size No No
geqo_seed No No
geqo_selection_bias No No
geqo_threshold No No
gin_fuzzy_search_limit No No
gin_pending_list_limit No No
google_columnar_engine.auto_columnarization_schedule No No
google_columnar_engine.enable_auto_columnarization No No
google_columnar_engine.enable_columnar_scan No No
google_columnar_engine.enabled Yes No
google_columnar_engine.memory_size_in_mb Yes No
google_columnar_engine.refresh_threshold_percentage No No
google_columnar_engine.refresh_threshold_scan_count No No
google_columnar_engine.relations No No
google_columnar_engine.scan_mode No No
google_db_advisor.auto_advisor_max_time_in_seconds No No
google_db_advisor.auto_advisor_schedule No No
google_db_advisor.enable_auto_advisor No No
google_db_advisor.enabled Yes No
google_db_advisor.max_index_width No No
google_db_advisor.max_num_indexable_columns No No
google_db_advisor.max_statement_length No No
google_db_advisor.max_storage_size_in_mb No No
google_db_advisor.recommendation_max_time_in_seconds No No
google_db_advisor.recommend_indexes_on_partitions No No
google_db_advisor.top_k_slowest_statements No No
hot_standby_feedback No No
idle_in_transaction_session_timeout No No
join_collapse_limit No No
lock_timeout No No
log_autovacuum_min_duration No No
log_checkpoints No No
log_connections No No
log_disconnections No No
log_duration No No
log_error_verbosity No No
log_executor_stats No No
log_hostname No No
log_lock_waits No No
log_min_duration_statement No No
log_min_error_statement No No
log_min_messages No No
log_parser_stats No No
log_planner_stats No No
log_replication_commands No No
log_statement No No
log_statement_stats No No
log_temp_files No No
maintenance_work_mem No No
max_connections Yes Yes
max_locks_per_transaction Yes Yes
max_logical_replication_workers Yes No
max_parallel_workers No No
max_parallel_workers_per_gather No No
max_pred_locks_per_page Yes No
max_pred_locks_per_relation Yes No
max_pred_locks_per_transaction Yes No
max_prepared_transactions Yes Yes
max_replication_slots Yes No
max_standby_archive_delay No No
max_standby_streaming_delay No No
max_sync_workers_per_subscription No No
max_wal_senders Yes Yes
max_wal_size No No
max_worker_processes Yes Yes
min_parallel_relation_size No No
min_wal_size No No
old_snapshot_threshold Yes No
parallel_setup_cost No No
parallel_tuple_cost No No
password_encryption No No
pg_bigm.enable_recheck No No
pg_bigm.gin_key_limit No No
pg_bigm.similarity_limit No No
pg_hint_plan.debug_print No No
pg_hint_plan.enable_hint No No
pg_hint_plan.enable_hint_table No No
pg_hint_plan.message_level No No
pg_hint_plan.parse_messages No No
pg_stat_statements.max Yes No No No
pg_stat_statements.track No No
pg_stat_statements.track_utility No No
pgaudit.log No No
pgaudit.log_catalog No No
pgaudit.log_client No No
pgaudit.log_level No No
pgaudit.log_parameter No No
pgaudit.log_relation No No
pgaudit.log_statement_once No No
pgaudit.role No No
pglogical.batch_inserts Yes No
pglogical.conflict_log_level No No
pglogical.conflict_resolution No No
pglogical.extra_connection_options No No
pglogical.synchronous_commit Yes No
pglogical.use_spi Yes No
random_page_cost No No
replacement_sort_tuples No No
shared_buffers Yes No
ssl_max_protocol_version No No
ssl_min_protocol_version No No
standard_conforming_strings No No
statement_timeout No No
synchronize_seqscans No No
tcp_keepalives_count No No
tcp_keepalives_idle No No
tcp_keepalives_interval No No
temp_buffers No No
temp_file_limit No No
trace_notify No No
trace_recovery_messages No No
trace_sort No No
track_activities No No
track_activity_query_size Yes No
track_commit_timestamp Yes No
track_counts No No
track_functions No No
track_io_timing No No
vacuum_cost_delay No No
vacuum_cost_limit No No
vacuum_freeze_min_age No No
vacuum_freeze_table_age No No
vacuum_multixact_freeze_min_age No No
vacuum_multixact_freeze_table_age No No
wal_buffers Yes No
work_mem No No