Part 3: Why Autovacuum Stops — PostgreSQL Internal Mechanics Explained
Series Summary: This is Part 3 of a multi-part series on PostgreSQL autovacuum failures.
In Part 2, we reproduced the autovacuum failure issue — now let’s understand why it happens. This post dives into PostgreSQL internals, explaining how autovacuum allocates its resources and why certain databases get “stuck” in maintenance limbo.
Why Does This Occur?
This behavior stems from how the autovacuum daemon allocates its resources. Autovacuum identifies the database with the oldest XID, and prioritizes it by assigning all available background workers to that database. As a result, …