Re: Configuring PostgreSQL to minimize impact of checkpoints

From: jao(at)geophile(dot)com
To: Vivek Khera <khera(at)kcilink(dot)com>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: Configuring PostgreSQL to minimize impact of checkpoints
Date: 2004-05-12 19:22:47
Message-ID: 1084389767.40a27987437da@geophile.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-performance

Quoting Vivek Khera <khera(at)kcilink(dot)com>:

> >>>>> "TL" == Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:
>
> TL> Jack Orenstein <jao(at)geophile(dot)com> writes:
> >> I'm looking at one case in which two successive transactions, each
> >> updating a handful of records, take 26 and 18 *seconds* (not msec) to
> >> complete. These transactions normally complete in under 30 msec.
>
> TL> I've seen installations in which it seemed that the "normal" query load
> TL> was close to saturating the available disk bandwidth, and the extra load
> TL> imposed by a background VACUUM just pushed the entire system's response
> TL> time over a cliff. In an installation that has I/O capacity to spare,
> ...
> TL> I suspect that the same observations hold true for checkpoints, though
> TL> I haven't specifically seen an installation suffering from that effect.
>
> I don't see that. But I also set checkpoint segments to about 50 on
> my big server.

But wouldn't that affect checkpoint frequency, not checkpoint cost?

Jack Orenstein

----------------------------------------------------------------
This message was sent using IMP, the Internet Messaging Program.

In response to

Responses

Browse pgsql-performance by date

  From Date Subject
Next Message Vivek Khera 2004-05-12 19:29:11 Re: Configuring PostgreSQL to minimize impact of checkpoints
Previous Message Vivek Khera 2004-05-12 19:05:05 Re: Configuring PostgreSQL to minimize impact of