I currently work on a project were AWS RDS PostgreSQL is used as a data storage. Since Postgres is using a mechanism called Multiversion Concurrency Control – MVCC, an UPDATE or DELETE command does not remove old versions of a row immediately. These are left on a disk, waiting to be collected and cleaned by a vacuum process. Vacuum can be automated and autovacuum serves that purpose.
Once autovacuum is configured, how do I know it works as expected? Is it triggered when I expect it to be?