On Thu, Jul 20, 2017 at 8:24 AM, Stephen Frost <sfr...@snowman.net> wrote: > * Tom Lane (t...@sss.pgh.pa.us) wrote: >> "Joshua D. Drake" <j...@commandprompt.com> writes: >> > At PGConf US Philly last week I was talking with Jim and Jan about >> > performance. One of the items that came up is that PostgreSQL can't run >> > full throttle for long periods of time. The long and short is that no >> > matter what, autovacuum can't keep up. This is what I have done: >> >> Try reducing autovacuum_vacuum_cost_delay more, and/or increasing >> autovacuum_vacuum_cost_limit. > > Or get rid of the cost delay entirely and let autovacuum actually go as > fast as it can when it's run. The assertion that it can't keep up is > still plausible, but configuring autovacuum to sleep regularly and then > complaining that it's not able to keep up doesn't make sense. > > Reducing the nap time might also be helpful if autovacuum is going as > fast as it can and it's able to clear a table in less than a minute. > > There have been discussions on this list about parallel vacuum of a > particular table as well; to address this issue I'd encourage reviewing > those discussions and looking at writing a patch to implement that > feature as that would address the case where the table is large enough > that autovacuum simply can't get through all of it before the other > backends have used all space available and then substantially increased > the size of the relation (leading to vacuum on the table running for > longer).
Yeah, the parallel vacuum of a particular table might help this issue unless disk I/O is bottle-neck. I'm planning work on that. Regards, -- Masahiko Sawada NIPPON TELEGRAPH AND TELEPHONE CORPORATION NTT Open Source Software Center -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers