PostgreSQL Settings

When creating a PostgreSQL database cluster, values for all settings are set automatically. The values are preset to ensure high cluster performance. The values differ depending on the cluster configuration and PostgreSQL version.

If the automatic values do not match your tasks, you can set your own values when creating a cluster or change settings in an already created cluster.

We recommend changing settings only if you know exactly why you need to do it, as incorrectly adjusted values can reduce cluster performance.

View the Settings List

Detailed description of settings is provided in the official PostgreSQL documentation.

You can view the list of settings that can be changed when creating a cluster or in an already created cluster when changing settings.

If you have previously changed settings, you can see a list of all changes.

  1. From the Control panel, go to the Cloud platform ⟶ Managed Databases section.
  2. Open the cluster page ⟶ Settings tab.
  3. The previously changed settings (name and value) will be displayed in the DBMS Settings block.

Change Settings

Changing some parameters in settings entails restarting the databases in the cluster — the cluster may not be available at that time. These settings depend on the PostgreSQL version — their list can be found [here](/selectel-cloud-platform/managed-databases/postgresql/postgresql_settings/#list-of-settings-that-require-a-restart).
  1. From the Control panel, go to the Cloud platform ⟶ Managed Databases section.
  2. Open the cluster page ⟶ Settings tab.
  3. Click Edit and specify the new values in the DBMS Settings block.
  4. Click Save.

List of Settings that Require a Restart

PostgreSQL 11

autovacuum_freeze_max_age, autovacuum_max_workers, autovacuum_multixact_freeze_max_age, max_files_per_process, max_pred_locks_per_transaction, max_prepared_transactions, old_snapshot_threshold, track_activity_query_size, max_connections, max_locks_per_transaction, max_worker_processes

PostgreSQL 12

autovacuum_freeze_max_age, autovacuum_max_workers, autovacuum_multixact_freeze_max_age, max_files_per_process, max_pred_locks_per_transaction, max_prepared_transactions, old_snapshot_threshold, track_activity_query_size, shared_buffers, max_connections, max_locks_per_transaction, max_worker_processes

PostgreSQL 13

shared_buffers, autovacuum_freeze_max_age, autovacuum_max_workers, autovacuum_multixact_freeze_max_age, max_connections, max_locks_per_transaction, max_pred_locks_per_transaction, max_prepared_transactions, max_worker_processes, old_snapshot_threshold, max_files_per_process, track_activity_query_size

PostgreSQL 12-TimescaleDB

autovacuum_freeze_max_age, autovacuum_max_workers, autovacuum_multixact_freeze_max_age, max_files_per_process, max_pred_locks_per_transaction, max_prepared_transactions, old_snapshot_threshold, track_activity_query_size, shared_buffers, max_connections, max_locks_per_transaction, max_worker_processes

PostgreSQL 13-TimescaleDB

max_files_per_process, autovacuum_freeze_max_age, autovacuum_max_workers, autovacuum_multixact_freeze_max_age, max_connections, max_locks_per_transaction, max_pred_locks_per_transaction, max_prepared_transactions, max_worker_processes, old_snapshot_threshold, track_activity_query_size, shared_buffers

PostgreSQL 10-1С

autovacuum_freeze_max_age, autovacuum_max_workers, autovacuum_multixact_freeze_max_age, max_files_per_process, max_pred_locks_per_transaction, max_prepared_transactions, old_snapshot_threshold, track_activity_query_size, shared_buffers, max_connections, max_locks_per_transaction, max_worker_processes

Settings when Scaling a Cluster

Each cluster configuration has limits of acceptable values. When scaling a cluster (changing its configuration), the values of some settings are automatically changed to acceptable ones for a proper cluster operation.

A list of settings that change values when scaling a cluster:

shared_buffers, effective_cache_size, maintenance_work_mem, max_worker_processes, max_parallel_workers, autovacuum_max_workers, vacuum_cost_limit, max_parallel_workers_per_gather, max_maintenance_workers

When the cluster is scaled up and its status changes to ACTIVE, you can set new values — change settings.