From: | Feike Steenbergen <feikesteenbergen(at)gmail(dot)com> |
---|---|
To: | PostgreSQL mailing lists <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Skip index cleanup if autovacuum did not do any work |
Date: | 2017-11-28 21:36:05 |
Message-ID: | CAK_s-G114rYyms0ZuYWQG5jP_OHApLHyJo9-Zmmt2z7vqAKcog@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
On a server with a very frequent xid wraparound I can see that the
anti-wraparound vacuum is finished very quickly with the heap, yet it still
scans all the indexes, which causes it to still have to read a lot of data,
which takes a considerable amount of time.
I dove into the code a bit and as far as I can tell, all the time spent for
doing this is is in lazy_cleanup_index.
For the very specific use case of all-frozen, basically read-only tables,
would it be ok to skip the lazy_cleanup_index call? As we are sure we did
not touch the heap or the index, I'd say a cleanup may not be necessary.
For this very specific usecase I would like to discuss whether or not this
is
a sane and/or good idea.
regards,
Feike
Attachment | Content-Type | Size |
---|---|---|
0001-skip_cleanup_for_stale_relation.patch | application/octet-stream | 1.1 KB |
From | Date | Subject | |
---|---|---|---|
Next Message | Tom Lane | 2017-11-28 21:38:12 | Re: pgindent run? |
Previous Message | Tom Lane | 2017-11-28 21:32:52 | Re: [HACKERS] postgres_fdw super user checks |