alloydb flags

This page describes the database flags that AlloyDB for PostgreSQL uses to enable and manage various service features unique to AlloyDB. For a list of all database flags that AlloyDB supports, see Supported database flags.

Flags marked with Instance restarts mean 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.

alloydb.enable_auto_explain

Typeboolean
Defaultoff
Instance restartsYes

Controls the availability of the auto_explain extension in an AlloyDB instance. Set the parameter to on and restart the instance. Then add the auto_explain extension to individual databases in the instance by using the CREATE EXTENSION command.

The auto_explain extension enables automatic logging of execution plans of slow statements, for troubleshooting and more. It provides an automated way to perform the functionality of the EXPLAIN command.

alloydb.enable_pg_bigm

Typeboolean
Defaultoff
Instance restartsYes

Controls the availability of the pg_bigm extension in an AlloyDB instance. Set the parameter to on and restart the instance. Then add the pg_bigm extension to individual databases in the instance by using the CREATE EXTENSION command.

The pg_bigm extension provides full text search capability in PostgreSQL using 2-gram (bigram) indexes for faster full text searches.

alloydb.enable_pg_cron

Typeboolean
Defaultoff
Instance restartsYes

Controls the availability of the pg_cron extension in an AlloyDB instance. Set the parameter to on and restart the instance. Then add the pg_cron extension to individual databases in the instance by using the CREATE EXTENSION command.

The pg_cron extension provides a simple cron-based job scheduler for PostgreSQL that runs inside the database as an extension. It uses the same syntax as regular cron, and it lets you schedule PostgreSQL commands directly from the database.

alloydb.enable_pg_hint_plan

Typeboolean
Defaultoff
Instance restartsYes

Controls the availability of the pg_hint_plan extension in an AlloyDB instance. Set the parameter to on and restart the instance. Then add the pg_hint_plan extension to individual databases in the instance by using the CREATE EXTENSION command.

The pg_hint_plan extension enables you to improve PostgreSQL execution plans using hints, which are simple descriptions in SQL comments.

alloydb.enable_pg_wait_sampling

Typeboolean
Defaultoff
Instance restartsYes

Enables AlloyDB to collect sampling statistics of wait events. Set the parameter to on and restart the instance. Then, add the pg_wait_sampling extension to individual databases in the instance by using the CREATE EXTENSION command.

The pg_wait_sampling extension aggregates and summarizes the wait event data. You can query these views to gain insights into wait times, frequencies, and relative importance of different wait events.

alloydb.enable_pgaudit

Typeboolean
Defaultoff
Instance restartsYes

Controls the availability of the pgaudit extension in an AlloyDB instance. Set the parameter to on and restart the instance. Then add the pgaudit extension to individual databases in the instance by using the CREATE EXTENSION command.

The pgaudit extension provides detailed session and object audit logging using the standard logging facility provided by PostgreSQL.

alloydb.enable_pglogical

Typeboolean
Defaultoff
Instance restartsYes

Controls the availability of the pglogical extension in an AlloyDB instance. Set the parameter to on and restart the instance. Then add the pglogical extension to individual databases in the instance by using the CREATE EXTENSION command.

The pglogical extension provides logical streaming replication for PostgreSQL using a publish/subscribe model.

alloydb.iam_authentication

Typeboolean
Defaultoff
Instance restartsYes

Enables the use of Identity and Access Management (IAM) authentication with an AlloyDB instance.

alloydb.logical_decoding

Typeboolean
Defaultoff
Instance restartsYes

Enables the PostgreSQL logical decoding infrastructure in an AlloyDB instance.

Logical decoding provides the infrastructure necessary to stream data modifications to external consumers.

alloydb.log_throttling_window

Typeinteger
Default0
Instance restartsNo

Controls whether AlloyDB records duplicate log messages received during a specified time window.

If set to a value greater than 0, then AlloyDB starts a timer that many seconds long whenever it records a log message. If AlloyDB receives the identical log message before the timer expires, it does not record the message. After the timer expires, AlloyDB appends a count of any skipped messages to the next occurrence of the same log message that it records.

If set to 0, then AlloyDB records all duplicate log messages.

alloydb.promote_cancel_to_terminate

Typeboolean
Defaultoff
Instance restartsNo

If set to true, then any query cancellation requests due to issues such as lock timeouts, statement timeouts, and recovery (replay) conflicts that AlloyDB encounters, are promoted to forced backend termination requests.

By promoting the cancellation requests, AlloyDB helps prevent stuck backends from blocking log replay and other backends.

alloydb.pg_shadow_select_role

Typestring
DefaultAn empty string
Instance restartsNo

Name of the PostgreSQL role that is to be used to grant permission to query the pg_shadow view.

google_storage.log_replay_throttle_read_transactions

Typeboolean
Defaulton
Instance restartsNo

Controls whether lag-based throttling of a read query is enabled on read nodes. If the parameter is set to on, then the read queries are throttled for up to one minute when replication lag exceeds one second.