Re: Slow PITR restore

From: "Joshua D(dot) Drake" <jd(at)commandprompt(dot)com>
To: Gregory Stark <stark(at)enterprisedb(dot)com>
Cc: Jeff Trout <threshar(at)threshar(dot)is-a-geek(dot)com>, pgsql-general(at)postgresql(dot)org
Subject: Re: Slow PITR restore
Date: 2007-12-12 20:25:56
Message-ID: 476043D4.7090501@commandprompt.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general pgsql-hackers

Gregory Stark wrote:
> "Joshua D. Drake" <jd(at)commandprompt(dot)com> writes:
>
>> On Wed, 12 Dec 2007 18:02:39 +0000
>> Gregory Stark <stark(at)enterprisedb(dot)com> wrote:
>>
>>> I'm not sure what you guys' expectations are, but if you're restoring
>>> 5 minutes worth of database traffic in 8 seconds I wouldn't be
>>> complaining.
>> I would be. This is a database that is doing nothing but restoring.
>> Zero concurrency. This thing should be flying.
>
> Well you say that like concurrency is a bad thing. The lack of concurrency is
> the big handicap recovery has. It has to wait while it loads one buffer so it
> can twiddle some bits before it reads the next buffer and twiddles bits there.
> During normal operation those two buffers were twiddled by two different
> transactions in two different processes. Even if they weren't on two different
> processes they could have been context switched onto the same processor while
> the i/o was in progress.

Please see my point about saturation in another post.

Joshua D. Drake

In response to

Browse pgsql-general by date

  From Date Subject
Next Message Richard Huxton 2007-12-12 20:27:34 Re: Altering field passed as parameter to plpgsql trigger
Previous Message Gregory Stark 2007-12-12 20:18:00 Re: Slow PITR restore

Browse pgsql-hackers by date

  From Date Subject
Next Message Andrew Dunstan 2007-12-12 20:45:45 Re: Trigger problem - conclusion
Previous Message Andrew Chernow 2007-12-12 20:18:17 PGparam proposal v2