| From: | Alvaro Herrera <alvherre(at)2ndquadrant(dot)com> |
|---|---|
| To: | Joe Conway <mail(at)joeconway(dot)com> |
| Cc: | Robert Haas <robertmhaas(at)gmail(dot)com>, Andres Freund <andres(at)anarazel(dot)de>, "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Allow to specify (auto-)vacuum cost limits relative to the database/cluster size? |
| Date: | 2016-02-24 16:54:03 |
| Message-ID: | 20160224165403.GA413518@alvherre.pgsql |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
Joe Conway wrote:
> In my experience it is almost always best to run autovacuum very often
> and very aggressively. That generally means tuning scaling factor and
> thresholds as well, such that there are never more than say 50-100k dead
> rows. Then running vacuum with no delays or limits runs quite fast is is
> generally not noticeable/impactful.
>
> However that strategy does not work well for vacuums which run long,
> such as an anti-wraparound vacuum. So in my opinion we need to think
> about this as at least two distinct cases requiring different solutions.
With the freeze map there is no need for anti-wraparound vacuums to be
terribly costly, since they don't need to scan the whole table each
time. That patch probably changes things a lot in this area.
--
Álvaro Herrera http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Petr Jelinek | 2016-02-24 17:35:16 | Re: Proposal: Generic WAL logical messages |
| Previous Message | Teodor Sigaev | 2016-02-24 16:51:48 | Re: GIN data corruption bug(s) in 9.6devel |