RDS database upgraded and restarted automatically despite having Auto Minor Version Upgrade disabled.

If you observe that your DB has been restarted during the weekly maintenance window and there was a patching activity performed on the database, please follow the following set of checks:

1/ Check the RDS Events by navigating to RDS Console > Select the DB instance/cluster > Go to Logs and Events tab > Recent events section and check the DB events if there was an event like "Database instance patched" followed with DB Restart.

A sample of Recent Events should look like this:

Time                                         System notes
July 06, 2025, 02:39 (UTC+05:30)            Performance Insights has been enabled
July 06, 2025, 02:39 (UTC+05:30)            Monitoring Interval changed to 0
July 06, 2025, 02:38 (UTC+05:30)            Database instance patched
July 06, 2025, 02:36 (UTC+05:30)            DB instance restarted
July 06, 2025, 02:35 (UTC+05:30)            DB instance shutdown

2/ If the Events show "Database instance patched" event the Logs and Events tab, In the RDS Console > select the database > Maintenance and backups tab > check if Maintenance shows Auto minor version upgrade as Enabled or Disabled

• If Enabled, it means since you have enabled the Auto minor version upgrade, your database was upgraded to most recent minor version. As engine version upgrades are followed with a restart, you observed the same on your database.

• If Disabled, it means that your Database was upgraded by AWS.

AWS performs a minor version upgrade automatically during the DB maintenance window under following circumstances:

• The database is running a minor DB engine version that is less than the current automatic upgrade minor version.
• The database has the Auto minor version upgrade option enabled.

To confirm weather the The database is running a minor DB engine version that is less than the current automatic upgrade minor version. , you can refer to the AWS Official Documentation with Release calendar for Amazon RDS for PostgreSQL minor versions and Release calendar for Aurora PostgreSQL major versions and refer the columns RDS end of standard support date and Aurora end of standard support date respectively.

Do I get a Notification when the minor version upgrade is scheduled ?

Yes, AWS sends an RDS operational notification in PHD (Personal Health Dashboard) Notifications 3 months in advance before beginning automatic upgrades to your database. The RDS operational notification looks like this:

Subject line: [Action Required] Amazon RDS for PostgreSQL is deprecating minor versions yy.xx on <Date>


You are receiving this message because you have one or more Amazon RDS for PostgreSQL DB instances running major version 'yy' without RDS Extended Support. PostgreSQL 'yy' will be deprecated by the community in <Month Year>, and will not receive any bug fixes or security patches after that. Following the community timeline, PostgreSQL 'yy' will reach RDS end of standard support on <date, Year>.

We recommend that you take action and upgrade your RDS for PostgreSQL 'yy' database (DB) instances to a higher major version, such as PostgreSQL 'zz', or higher, before end of standard support on < Date, Year>. 

If you have not upgraded to a newer major version by <Date, Year>, Amazon RDS will automatically upgrade your Extended Support-disabled PostgreSQL 'yy' databases to PostgreSQL 'zz', or higher during a scheduled maintenance window between <Date 1> and <Date 2>. After <date 2>, any Extended Support disabled PostgreSQL 'yy' databases that remain will be automatically upgraded to version 'zz', or higher regardless of your scheduled maintenance window.

Important:

Per AWS documentation Getting started with your AWS Health Dashboard – Your account health, Personal Health Dashboard (PHD) has a 90-day event retention policy. Any RDS operational notification becomes inaccessible in PHD after 90 days from its original notification date.

Resolution :

To prevent your DB from unexpected restarts due to minor version upgrades done due to running on running a minor DB engine version that is less than the current automatic upgrade minor version, you can consider using RDS Extended Support / Aurora PostgreSQL long-term support (LTS). Amazon RDS won't upgrade your minor version until after the RDS end of standard support date for your major engine version. Refer RDS Extended Support and Aurora PostgreSQL long-term support (LTS)To know more about RDS Extended Support and Aurora PostgreSQL long-term support (LTS).