Horton

Re: pgsql: Improve autovacuum logging for aggressive and anti-wraparound ru

Michael Paquier <michael@paquier.xyz>

View thread View on postgr.es
From: Michael Paquier <michael@paquier.xyz>
To: Andrew Dunstan <andrew.dunstan@2ndquadrant.com>
Cc: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>, sawada.mshk@gmail.com, tgl@sss.pgh.pa.us, alvherre@2ndquadrant.com, sk@zsrv.org, nasbyj@amazon.com, andres@anarazel.de, robertmhaas@gmail.com, pgsql-hackers@lists.postgresql.org
Date: 2019-03-29T14:03:49Z
Lists: pgsql-hackers 
On Fri, Mar 29, 2019 at 09:11:47AM -0400, Andrew Dunstan wrote:
> +                (errmsg_internal("found vacuum to prevent wraparound of
> table \"%s.%s.%s\" to be not aggressive, so skipping",
> 
> This might convey something to hackers, but I doubt it will convey much
> to regular users. Perhaps something like "skipping redundant
> anti-wraparound vacuum of table ..." would be better.

"skipping redundant" is much better.

> The comment is also a bit too tentative. Perhaps something like this
> would do:
> 
>     Normally the relfrozenxid for an anti-wraparound vacuum will be old
>     enough to force an aggressive vacuum. However, a concurrent vacuum
>     might have already done this work that the relfroxzenxid in relcache
>     has been updated. If that happens this vacuum is redundant, so skip it.

That works for me.
--
Michael

Commits

  1. Skip redundant anti-wraparound vacuums

  2. Improve autovacuum logging for aggressive and anti-wraparound runs

  3. In relevant log messages, indicate whether vacuums are aggressive.

  4. Don't vacuum all-frozen pages.