Is vacuuming a PostgreSQL materialized view necessary?

Question

I understand it makes sense to analyze a Materialized View (MV), but since MVs are not updateable, does that imply that we need not ever vacuum a MV?

Answer 1

Materialized views need to be vacuumed:

1. At some point, old rows need to be “frozen” to prevent data loss when the transaction ID counter wraps around.

2. If you use REFRESH MATERIALIZED VIEW CONCURRENTLY, dead tuples are created and need to be removed by VACUUM.