Re: Group Commit - Mailing list pgsql-hackers

From Greg Smith
Subject Re: Group Commit
Date
Msg-id Pine.GSO.4.64.0704092249360.21736@westnet.com
Whole thread Raw
In response to Re: Group Commit  (Bruce Momjian <bruce@momjian.us>)
Responses Re: Group Commit  (Tom Lane <tgl@sss.pgh.pa.us>)
Re: Group Commit  (Tatsuo Ishii <ishii@postgresql.org>)
List pgsql-hackers
On Mon, 9 Apr 2007, Bruce Momjian wrote:

> The big question is who is going to care about the milliseconds delay
> and is using a configuration that is going to benefit from commit_delay.

I care.  WAL writes are a major bottleneck when many clients are 
committing near the same time.  Both times I've played with the 
commit_delay settings I found it improved the peak throughput under load 
at an acceptable low cost in latency.  I'll try to present some numbers on 
that when I get time, before you make me cry by taking it away.

An alternate mechanism that tells the client the commit is done when it 
hasn't hit disk is of no use for the applications I work with, so I 
haven't even been paying attention to no-commit-wait.

--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD


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