Re: Managing autovacuum freezing

On Thu, Feb 11, 2021 at 9:13 AM Don Seiler <don(at)seiler(dot)us> wrote:
> My understanding is that these manual VACUUM ANALYZE jobs are not freezing rows that regular autovacuuming would otherwise be doing, which leads up to the big anti-wraparound job.

They will freeze rows, but not aggressively. The antiwraparound vacuum
might block on acquiring buffer pins, low level stuff like that.

Perhaps you should change the vacuum_index_cleanup reloption to 'off'
for the table, but make the scripted overnight vacuums directly
specify INDEX_CLEANUP=on. That way index cleanup would still be
performed for the vacuums that run overnight, though not for the
antiwraparound vacuums, where the overhead may be a real issue.

--
Peter Geoghegan