Select a documentation version: <button class="button button-with-icon cloud-select-dropdown__button button-primary" aria-haspopup="true">18.4.0</button>

- [Current (18.4.0)](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/database-flags.md.txt)
- [18.4.0](https://docs.cloud.google.com/alloydb/omni/containers/18.4.0/docs/reference/database-flags.md.txt)
- [18.3.0](https://docs.cloud.google.com/alloydb/omni/containers/18.3.0/docs/reference/database-flags.md.txt)
- [18.1.0](https://docs.cloud.google.com/alloydb/omni/containers/18.1.0/docs/reference/database-flags.md.txt)
- [17.10.0](https://docs.cloud.google.com/alloydb/omni/containers/17.10.0/docs/reference/database-flags.md.txt)
- [17.9.0](https://docs.cloud.google.com/alloydb/omni/containers/17.9.0/docs/reference/database-flags.md.txt)
- [17.7.0](https://docs.cloud.google.com/alloydb/omni/containers/17.7.0/docs/reference/database-flags.md.txt)
- [17.5.0](https://docs.cloud.google.com/alloydb/omni/containers/17.5.0/docs/reference/database-flags.md.txt)
- [16.14.0](https://docs.cloud.google.com/alloydb/omni/containers/16.14.0/docs/reference/database-flags.md.txt)
- [16.13.0](https://docs.cloud.google.com/alloydb/omni/containers/16.13.0/docs/reference/database-flags.md.txt)
- [16.11.0](https://docs.cloud.google.com/alloydb/omni/containers/16.11.0/docs/reference/database-flags.md.txt)
- [16.9.0](https://docs.cloud.google.com/alloydb/omni/containers/16.9.0/docs/reference/database-flags.md.txt)
- [16.8.0](https://docs.cloud.google.com/alloydb/omni/containers/16.8.0/docs/reference/database-flags.md.txt)
- [16.3.0](https://docs.cloud.google.com/alloydb/omni/containers/16.3.0/docs/reference/database-flags.md.txt)
- [15.18.0](https://docs.cloud.google.com/alloydb/omni/containers/15.18.0/docs/reference/database-flags.md.txt)
- [15.17.0](https://docs.cloud.google.com/alloydb/omni/containers/15.17.0/docs/reference/database-flags.md.txt)
- [15.15.0](https://docs.cloud.google.com/alloydb/omni/containers/15.15.0/docs/reference/database-flags.md.txt)
- [15.13.0](https://docs.cloud.google.com/alloydb/omni/containers/15.13.0/docs/reference/database-flags.md.txt)
- [15.12.0](https://docs.cloud.google.com/alloydb/omni/containers/15.12.0/docs/reference/database-flags.md.txt)
- [15.7.1](https://docs.cloud.google.com/alloydb/omni/containers/15.7.1/docs/reference/database-flags.md.txt)
- [15.7.0](https://docs.cloud.google.com/alloydb/omni/containers/15.7.0/docs/reference/database-flags.md.txt)

<br />

AlloyDB Omni supports all database flags provided by standard [PostgreSQL](https://www.postgresql.org/docs/18/index.html) versions. This page lists the database flags that AlloyDB Omni provides in addition to the standard database flags.

<br />

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](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/configure-database-flags.md.txt).


## 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.

  <br />

| AlloyDB Omni flag | Default value | Restart required | Replica restrictions |
|---|---|---|---|
| [alloydb.ai_nl_enabled](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/alloydb-flags.md.txt#alloydb.ai_nl_enabled) | `off` | No | No |
| [alloydb.audit_log_line_prefix](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/alloydb-flags.md.txt#alloydb.audit_log_line_prefix) | `%m [%p]: [%l-1] db=%d,user=%u` | Yes | No |
| [alloydb.enable_pgaudit](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/alloydb-flags.md.txt#alloydb.enable_pgaudit) | `off` | Yes | No |
| [alloydb.enable_named_hints](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/alloydb-flags.md.txt#alloydb.enable_query_plan_patch) | `off` | No | No |
| [alloydb.iam_authentication](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/alloydb-flags.md.txt#alloydb.iam_authentication) | `off` | Yes | No |
| [alloydb.logical_decoding](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/alloydb-flags.md.txt#alloydb.logical_decoding) | `off` | Yes | No |
| [alloydb.log_throttling_window](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/alloydb-flags.md.txt#alloydb.log_throttling_window) | No | No |
| [alloydb.promote_cancel_to_terminate](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/alloydb-flags.md.txt#alloydb.promote_cancel_to_terminate) | `off` | No | No |
| [alloydb.pg_shadow_select_role](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/alloydb-flags.md.txt#alloydb.pg_shadow_select_role) | An empty string | No | No |
| [enable_google_adaptive_autovacuum](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/adaptive-autovacuum.md.txt) | `on` | No | No |
| enable_parallel_nestloop_inner_material | `off` | No | No |
| [google_columnar_engine.auto_columnarization_schedule](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/columnar-engine-flags.md.txt#auto-columnarization-schedule) | `'EVERY 1 HOUR'` | No | No |
| [google_columnar_engine.enable_auto_columnarization](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/columnar-engine-flags.md.txt#enable-auto-columnarization) | `on` | No | No |
| [google_columnar_engine.enable_columnar_scan](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/columnar-engine-flags.md.txt#enable-columnar-scan) | `on` | No | No |
| [google_columnar_engine.enable_virtual_columns_scan](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/columnar-engine-flags.md.txt#google_columnar_engine.enable_virtual_columns_scan) | `off` | No | No |
| [google_columnar_engine.enable_vectorized_join](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/columnar-engine-flags.md.txt#enable-vectorized-join) | `off` | No | No |
| [google_columnar_engine.enabled](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/columnar-engine-flags.md.txt#enabled) | `off` | Yes | No |
| [google_columnar_engine.memory_size_in_mb](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/columnar-engine-flags.md.txt#memory-size-in-mb) | 30% of instance RAM | Yes | No |
| [google_columnar_engine.omni_storage_cache_directory](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/columnar-engine-flags.md.txt#omni-storage-cache-directory) | An empty string | Yes | No |
| [google_columnar_engine.refresh_threshold_percentage](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/columnar-engine-flags.md.txt#refresh-threshold-percentage) | `50` | No | No |
| [google_columnar_engine.refresh_threshold_scan_count](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/columnar-engine-flags.md.txt#refresh-threshold-scan-count) | `5` | No | No |
| [google_columnar_engine.relations](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/columnar-engine-flags.md.txt#relations) | An empty string | No | No |
| [google_columnar_engine.vectorized_join_threads](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/columnar-engine-flags.md.txt#vectorized-join-threads) | 1 | No | No |
| [google_db_advisor.auto_advisor_max_time_in_seconds_per_day](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/index-advisor-flags.md.txt#auto_advisor_max_time_in_seconds_per_day) | `1800` | No | No |
| [google_db_advisor.auto_advisor_schedule](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/index-advisor-flags.md.txt#auto_advisor_schedule) | `'EVERY 24 HOURS'` | No | No |
| [google_db_advisor.enable_auto_advisor](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/index-advisor-flags.md.txt#enable_auto_advisor) | `on` | No | No |
| [google_db_advisor.enabled](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/index-advisor-flags.md.txt#enabled) | `on` | Yes | No |
| [google_db_advisor.max_index_width](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/index-advisor-flags.md.txt#max_index_width) | `2` | No | No |
| [google_db_advisor.max_num_indexable_columns](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/index-advisor-flags.md.txt#max_num_indexable_columns) | `1000` | No | No |
| [google_db_advisor.max_statement_length](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/index-advisor-flags.md.txt#max_statement_length) | `102400` | No | No |
| [google_db_advisor.max_storage_size_in_mb](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/index-advisor-flags.md.txt#max_storage_size_in_mb) | `0` | No | No |
| [google_db_advisor.recommendation_max_time_in_seconds](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/index-advisor-flags.md.txt#recommendation_max_time_in_seconds) | `600` | No | No |
| [google_db_advisor.recommend_indexes_on_partitions](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/index-advisor-flags.md.txt#recommend_indexes_on_partitions) | `off` | No | No |
| [google_db_advisor.top_k_slowest_statements](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/index-advisor-flags.md.txt#top_k_slowest_statements) | `100` | No | No |
| [google_job_scheduler.maintenance_cpu_percentage](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/columnar-engine-flags.md.txt#maintenance-cpu-percentage) | `20` | No | No |
| [google_job_scheduler.max_parallel_workers_per_job](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/columnar-engine-flags.md.txt#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](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/model-endpoint-reference) | `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](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/alloydb-flags.md.txt#google_storage.log_replay_throttle_read_transactions) | `on` | No | No |
| [scann.enable_index_with_insufficient_data](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/alloydb-flags.md.txt#scann.enable_index_with_insufficient_data) | off | No | No |
| [scann.enable_preview_features](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/alloydb-flags.md.txt#scann.enable_preview_features) | off | Yes | No |
| [scann.maintenance_background_naptime_s](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/alloydb-flags.md.txt#scann.maintenance_background_naptime_s) | 1 minute | Yes | No |
| [omni_enable_telemetry](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/alloydb-flags.md.txt#telemetry) | `on` | Yes | No |
| [password.enforce_password_does_not_contain_username](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/password-policy-flags.md.txt#enforce_password_does_not_contain_username) | `OFF` | No | No |
| [password.enforce_expiration](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/password-policy-flags.md.txt#enforce-expiration) | `OFF` | No | No |
| [password.enforce_complexity](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/password-policy-flags.md.txt#enforce-complexity) | `OFF` | No | No |
| [password.expiration_in_days](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/password-policy-flags.md.txt#expiration-in-days) | `90` | No | No |
| [password.min_uppercase_letters](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/password-policy-flags.md.txt#min-uppercase-letters) | `0` | No | No |
| [password.max_uppercase_letters](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/password-policy-flags.md.txt#max-uppercase-letters) | `1000` | No | No |
| [password.min_lowercase_letters](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/password-policy-flags.md.txt#min-lowercase-letters) | `0` | No | No |
| [password.max_lowercase_letters](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/password-policy-flags.md.txt#max-lowercase-letters) | `1000` | No | No |
| [password.min_numerical_chars](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/password-policy-flags.md.txt#min-numerical-chars) | `0` | No | No |
| [password.max_numerical_chars](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/password-policy-flags.md.txt#max-numerical-chars) | `1000` | No | No |
| [password.min_special_chars](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/password-policy-flags.md.txt#min-special-chars) | `0` | No | No |
| [password.max_special_chars](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/password-policy-flags.md.txt#max-special-chars) | `1000` | No | No |
| [password.min_pass_length](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/password-policy-flags.md.txt#min-pass-length) | `0` | No | No |
| [password.max_pass_length](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/password-policy-flags.md.txt#max-pass-length) | `1000` | No | No |
| [password.notify_expiration_in_days](https://docs.cloud.google.com/alloydb/omni/containers/current/docs/reference/password-policy-flags.md.txt#notify-expiration-in-days) | `30` | No | No |
| [squeeze.worker_autostart](https://github.com/cybertec-postgresql/pg_squeeze#enable--disable-table-processing) | Standard default | No | No |
| [squeeze.worker_role](https://github.com/cybertec-postgresql/pg_squeeze#enable--disable-table-processing) | Standard default | No | No |
| [squeeze.workers_per_database](https://github.com/cybertec-postgresql/pg_squeeze#running-multiple-workers-per-database) | Default value is `1` | No | No |
| [squeeze.max_xlock_time](https://github.com/cybertec-postgresql/pg_squeeze#control-the-impact-on-other-backends) | 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](https://www.postgresql.org/docs/18/runtime-config-autovacuum.html#GUC-AUTOVACUUM-FREEZE-MAX-AGE) | Yes |
| [autovacuum_max_workers](https://www.postgresql.org/docs/18/runtime-config-autovacuum.html#GUC-AUTOVACUUM-MAX-WORKERS) | Yes |
| [autovacuum_multixact_freeze_max_age](https://www.postgresql.org/docs/18/runtime-config-autovacuum.html#GUC-AUTOVACUUM-MULTIXACT-FREEZE-MAX-AGE) | Yes |
| [autovacuum_vacuum_max_threshold](https://www.postgresql.org/docs/18/runtime-config-autovacuum.html#GUC-AUTOVACUUM-VACUUM-MAX-THRESHOLD) | No |
| [commit_timestamp_buffers](https://www.postgresql.org/docs/18/runtime-config-resource.html#GUC-COMMIT-TIMESTAMP-BUFFERS) | Yes |
| [cron.database_name](https://github.com/citusdata/pg_cron#what-is-pg_cron) | Yes |
| [cron.log_run](https://github.com/citusdata/pg_cron/blob/main/src/pg_cron.c) | Yes |
| [cron.log_statement](https://github.com/citusdata/pg_cron/blob/main/src/pg_cron.c) | Yes |
| [cron.max_running_jobs](https://github.com/citusdata/pg_cron/blob/main/src/pg_cron.c) | Yes |
| [max_connections](https://www.postgresql.org/docs/18/runtime-config-connection.html#GUC-MAX-CONNECTIONS) | Yes |
| [max_locks_per_transaction](https://www.postgresql.org/docs/18/runtime-config-locks.html#GUC-MAX-LOCKS-PER-TRANSACTION) | Yes |
| [max_logical_replication_workers](https://www.postgresql.org/docs/18/runtime-config-replication.html#GUC-MAX-LOGICAL-REPLICATION-WORKERS) | Yes |
| [max_notify_queue_pages](https://www.postgresql.org/docs/18/runtime-config-resource.html#GUC-MAX-NOTIFY-QUEUE-PAGES) | Yes |
| [max_pred_locks_per_page](https://www.postgresql.org/docs/18/runtime-config-locks.html#GUC-MAX-PRED-LOCKS-PER-PAGE) | Yes |
| [max_pred_locks_per_relation](https://www.postgresql.org/docs/18/runtime-config-locks.html#GUC-MAX-PRED-LOCKS-PER-RELATION) | Yes |
| [max_pred_locks_per_transaction](https://www.postgresql.org/docs/18/runtime-config-locks.html#GUC-MAX-PRED-LOCKS-PER-TRANSACTION) | Yes |
| [max_prepared_transactions](https://www.postgresql.org/docs/18/runtime-config-resource.html#GUC-MAX-PREPARED-TRANSACTIONS) | Yes |
| [max_replication_slots](https://www.postgresql.org/docs/18/runtime-config-replication.html#GUC-MAX-REPLICATION-SLOTS) | Yes |
| [max_wal_senders](https://www.postgresql.org/docs/18/runtime-config-replication.html#GUC-MAX-WAL-SENDERS) | Yes |
| [max_worker_processes](https://www.postgresql.org/docs/18/runtime-config-resource.html#GUC-MAX-WORKER-PROCESSES) | Yes |
| [old_snapshot_threshold](https://www.postgresql.org/docs/18/runtime-config-resource.html#GUC-OLD-SNAPSHOT-THRESHOLD) | Yes |
| [multixact_member_buffers](https://www.postgresql.org/docs/18/runtime-config-resource.html#GUC-MULTIXACT-MEMBER-BUFFERS) | Yes |
| [multixact_offset_buffers](https://www.postgresql.org/docs/18/runtime-config-resource.html#GUC-MULTIXACT-OFFSET-BUFFERS) | Yes |
| [notify_buffers](https://www.postgresql.org/docs/18/runtime-config-resource.html#GUC-NOTIFY-BUFFERS) | Yes |
| [pg_stat_statements.max](https://www.postgresql.org/docs/18/pgstatstatements.html#id-1.11.7.38.8) | Yes |
| [pglogical.batch_inserts](https://github.com/2ndQuadrant/pglogical#configuration-options) | Yes |
| [pglogical.synchronous_commit](https://github.com/2ndQuadrant/pglogical#synchronous-replication) | Yes |
| [pglogical.use_spi](https://github.com/2ndQuadrant/pglogical#configuration-options) | Yes |
| [shared_buffers](https://www.postgresql.org/docs/18/runtime-config-resource.html#GUC-SHARED-BUFFERS) | Yes |
| [serializable_buffers](https://www.postgresql.org/docs/18/runtime-config-resource.html#GUC-SERIALIZABLE-BUFFERS) | Yes |
| [subtransaction_buffers](https://www.postgresql.org/docs/18/runtime-config-resource.html#GUC-SUBTRANSACTION-BUFFERS) | Yes |
| [track_activity_query_size](https://www.postgresql.org/docs/18/runtime-config-statistics.html#GUC-TRACK-ACTIVITY-QUERY-SIZE) | Yes |
| [track_commit_timestamp](https://www.postgresql.org/docs/18/runtime-config-replication.html#GUC-TRACK-COMMIT-TIMESTAMP) | Yes |
| [transaction_buffers](https://www.postgresql.org/docs/18/runtime-config-resource.html#GUC-TRANSACTION-BUFFERS) | Yes |
| [wal_buffers](https://www.postgresql.org/docs/18/runtime-config-wal.html#GUC-WAL-BUFFERS) | Yes |