Re: pg_stat_all_tables.last_vacuum not always correct.

Kathleen Emerson <heavylivestock@gmail.com> writes:
> I ran `VACUUM VERBOSE` on 10-28. After the VACUUM completed, I ran the
> query
> `SELECT relname, last_vacuum FROM pg_stat_all_tables ORDER BY 2;`
> [ and saw old timestamps for some ]
> So, at least according to the VERBOSE logs, it seems like these tables
> _were_ vacuumed. Why the discrepancy?

The pg_stats mechanism is designed to drop messages when under sufficient
load, so if there was a whole lot going on besides the VACUUM, maybe
that would explain it.

            regards, tom lane