Review the Cloud SQL PostgreSQL server-log threshold

Description

PostgreSQL log_min_messages sets the minimum message level included in server logs. Its default is WARNING, and a more detailed level can be justified for diagnostics. Client messages and SQL statement auditing are separate settings.

Potential impact

Unnecessary detail can obscure important errors and increase storage costs.
An overly high threshold can omit warnings or errors needed for investigations.

Remediation

Use WARNING as a starting point and set log_min_messages to meet operational and diagnostic needs. Review temporary detailed settings when diagnostics end.
Check actual log usefulness and volume, and configure required retention and access permissions.

Examples

These excerpts compare part of the instance settings. Use a supported engine version and supply omitted required settings. Changing this flag does not require the engine-version change shown here.

Before

hcl

resource "google_sql_database_instance" "example" {
  name             = "postgres-instance-with-flag"
  database_version = "POSTGRES_14"
  region           = "us-central1"

  settings {
    database_flags {
      name  = "log_min_messages"
      value = "NOTICE"
    }
  }
}

After

hcl

resource "google_sql_database_instance" "example" {
  name             = "postgres-instance-with-flag"
  database_version = "POSTGRES_15"
  region           = "us-central1"

  settings {
    database_flags {
      name  = "log_min_messages"
      value = "WARNING"
    }
  }
}

Explanation:

Before: Server messages are logged from NOTICE upward. This can be appropriate when more detailed diagnostics are needed.
After: Messages are logged from WARNING upward. Verify that required records remain available.