Supported database flags

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AlloyDB Omni supports all database flags provided by standard PostgreSQL versions. This page lists the database flags that AlloyDB Omni provides in addition to the standard database flags.

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 Omni, see Configure AlloyDB Omni database flags.

AlloyDB Omni flags

The table's other columns contain additional information about each AlloyDB Omni flag:

  • Click a flag name to see its usage instructions.

  • The Default value column displays the value that AlloyDB Omni sets for this flag in a new instance, unless you specify a different value when creating the instance.

    Standard default indicates that the flag has a default value that's not set by AlloyDB Omni. To learn more, click the flag's name.

  • In the Restart required column, Yes indicates that you need to restart AlloyDB Omni when you set, remove, or modify the flag on the instance. The flag's value persists for the instance until you modify it again.

  • In the Replica 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 replica instances.

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

AlloyDB Omni flag Default value Restart required Replica restrictions
alloydb.audit_log_line_prefix %m [%p]: [%l-1] db=%d,user=%u Yes No
alloydb.enable_pgaudit off Yes No
alloydb.log_throttling_window No No
alloydb.promote_cancel_to_terminate off No No
alloydb.pg_shadow_select_role An empty string No No
alloydb.enable_pg_squeeze off No No
enable_google_adaptive_autovacuum on No No
enable_parallel_nestloop_inner_material off No No
google_columnar_engine.auto_columnarization_schedule 'EVERY 1 HOUR' No No
google_columnar_engine.enable_auto_columnarization on No No
google_columnar_engine.enable_columnar_scan on No No
google_columnar_engine.enabled off Yes No
google_columnar_engine.memory_size_in_mb 30% of instance RAM Yes No
google_columnar_engine.omni_storage_cache_directory An empty string Yes No
google_columnar_engine.refresh_threshold_percentage 50 No No
google_columnar_engine.refresh_threshold_scan_count 5 No No
google_columnar_engine.relations An empty string No No
google_db_advisor.auto_advisor_max_time_in_seconds 1800 No No
google_db_advisor.auto_advisor_schedule 'EVERY 24 HOURS' No No
google_db_advisor.enable_auto_advisor on No No
google_db_advisor.enabled on Yes No
google_db_advisor.max_index_width 2 No No
google_db_advisor.max_num_indexable_columns 1000 No No
google_db_advisor.max_statement_length 102400 No No
google_db_advisor.max_storage_size_in_mb 0 No No
google_db_advisor.recommendation_max_time_in_seconds 600 No No
google_db_advisor.recommend_indexes_on_partitions off No No
google_db_advisor.top_k_slowest_statements 100 No No
google_job_scheduler.maintenance_cpu_percentage 20 No No
google_job_scheduler.max_parallel_workers_per_job 2 No No
google_ml_integration.cursor_group_size 500 No No
google_ml_integration.default_llm_model gemini-2.5-flash-lite No No
google_ml_integration.embedding_request_timeout 300 No No
google_ml_integration.enable_ai_query_engine on No No
google_ml_integration.enable_faster_embedding_generation on No No
google_ml_integration.enable_forecasting on No No
google_ml_integration.enable_list_models off No No
google_ml_integration.enable_model_support off No
google_ml_integration.enable_preview_ai_functions off No No
google_ml_integration.max_memory_usage_mb 1024 No No
google_ml_integration.max_parallel_requests 400 No No
google_ml_integration.request_timeout_in_seconds 60 No No
google_storage.log_replay_throttle_read_transactions on No No
password.enforce_password_does_not_contain_username OFF No No
password.enforce_expiration OFF No No
password.enforce_complexity OFF No No
password.expiration_in_days 90 No No
password.min_uppercase_letters 0 No No
password.max_uppercase_letters 1000 No No
password.min_lowercase_letters 0 No No
password.max_lowercase_letters 1000 No No
password.min_numerical_chars 0 No No
password.max_numerical_chars 1000 No No
password.min_special_chars 0 No No
password.max_special_chars 1000 No No
password.min_pass_length 0 No No
password.max_pass_length 1000 No No
password.notify_expiration_in_days 30 No No
squeeze.worker_autostart Standard default No No
squeeze.worker_role Standard default No No
squeeze.workers_per_database Default value is 1 No No
squeeze.max_xlock_time Default value is 1. Set to any value between 1 and 2147483647 No No
tde_kek_url An empty string No No

Standard PostgreSQL flags

AlloyDB Omni supports the following standard PostgreSQL flags. Some flags require a restart of AlloyDB Omni when you set, remove, or modify the flag on the instance. The flag's value persists for the instance until you modify it again.

PostgreSQL flag name Restart required
autovacuum_freeze_max_age Yes
autovacuum_max_workers Yes
autovacuum_multixact_freeze_max_age Yes
autovacuum_vacuum_max_threshold No
commit_timestamp_buffers Yes
cron.database_name Yes
cron.log_run Yes
cron.log_statement Yes
cron.max_running_jobs Yes
max_connections Yes
max_locks_per_transaction Yes
max_logical_replication_workers Yes
max_notify_queue_pages Yes
max_pred_locks_per_page Yes
max_pred_locks_per_relation Yes
max_pred_locks_per_transaction Yes
max_prepared_transactions Yes
max_replication_slots Yes
max_wal_senders Yes
max_worker_processes Yes
old_snapshot_threshold Yes
multixact_member_buffers Yes
multixact_offset_buffers Yes
notify_buffers Yes
pg_stat_statements.max Yes
pglogical.batch_inserts Yes
pglogical.synchronous_commit Yes
pglogical.use_spi Yes
shared_buffers Yes
serializable_buffers Yes
subtransaction_buffers Yes
track_activity_query_size Yes
track_commit_timestamp Yes
transaction_buffers Yes
wal_buffers Yes