In this post, I am sharing a system view which we can use to check the progress of running vacuum process of PostgreSQL.

PostgreSQL based on MVCC, and in this architecture VACUUM is a routine task of DBA for removing dead tuples.

What is Multi Version Concurrency Control (MVCC)

Now the question is, How to monitor the progress of VACUUM?

Simple, we can use pg_stat_progress_vacuum view for this purpose. In this view, we can check phase column which indicates the different stages of running the vacuum.

select * from pg_stat_progress_vacuum

Type of phases:

initializing: VACUUM is preparing to begin scanning the heap
scanning heap: VACUUM is currently scanning the heap
vacuuming indexes: VACUUM is currently vacuuming the indexes
vacuuming heap: VACUUM is currently vacuuming the heap
cleaning up indexes: VACUUM is currently cleaning up indexes
truncating heap: VACUUM is currently truncating the heap to return empty pages at the end of the relation to the operating system
performing final cleanup: VACUUM is performing final cleanup. During this phase, VACUUM will vacuum the free space map, update statistics in pg_class, and report statistics to the statistics collector

PostgreSQL: What is a Free Space Map (FSM)?

Reference taken from the official page: