Re: moving pg_xlog -- yeah, it's worth it!

From: Alvaro Herrera
Subject: Re: moving pg_xlog -- yeah, it's worth it!
Date: ,
Msg-id: 20100212141036.GB3737@alvh.no-ip.org
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In response to: Re: moving pg_xlog -- yeah, it's worth it!  (Alvaro Herrera)
Responses: Re: moving pg_xlog -- yeah, it's worth it!  ("Kevin Grittner")
List: pgsql-performance

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moving pg_xlog -- yeah, it's worth it!  ("Kevin Grittner", )
 Re: moving pg_xlog -- yeah, it's worth it!  (Jesper Krogh, )
  Re: moving pg_xlog -- yeah, it's worth it!  ("Kevin Grittner", )
   Re: moving pg_xlog -- yeah, it's worth it!  (Amitabh Kant, )
    Re: moving pg_xlog -- yeah, it's worth it!  ("Kevin Grittner", )
   Re: moving pg_xlog -- yeah, it's worth it!  (Bruce Momjian, )
    Re: moving pg_xlog -- yeah, it's worth it!  (Scott Marlowe, )
   Re: moving pg_xlog -- yeah, it's worth it!  ("Kevin Grittner", )
    Re: moving pg_xlog -- yeah, it's worth it!  (Alvaro Herrera, )
     Re: moving pg_xlog -- yeah, it's worth it!  (Aidan Van Dyk, )
      Re: moving pg_xlog -- yeah, it's worth it!  ("Kevin Grittner", )
 Re: moving pg_xlog -- yeah, it's worth it!  ("Kevin Grittner", )
  Re: moving pg_xlog -- yeah, it's worth it!  (Alvaro Herrera, )
   Re: moving pg_xlog -- yeah, it's worth it!  (Alvaro Herrera, )
    Re: moving pg_xlog -- yeah, it's worth it!  ("Kevin Grittner", )
     Re: moving pg_xlog -- yeah, it's worth it!  (Alvaro Herrera, )
  Re: moving pg_xlog -- yeah, it's worth it!  (Greg Smith, )
   Re: moving pg_xlog -- yeah, it's worth it!  ("Kevin Grittner", )
    Re: moving pg_xlog -- yeah, it's worth it!  (Ben Chobot, )

Alvaro Herrera wrote:
> Kevin Grittner wrote:

> > Anyway, given that these are replication
> > targets, and aren't the "database of origin" for any data of their
> > own, I guess there's no reason not to try asynchronous commit.
>
> Yeah; since the transactions only ever write commit records to WAL, it
> wouldn't matter a bit that they are lost on crash.  And you should see
> an improvement, because they wouldn't have to flush at all.

Actually, a transaction that performed no writes doesn't get a commit
WAL record written, so it shouldn't make any difference at all.

--
Alvaro Herrera                                http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support


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Subject: Re: moving pg_xlog -- yeah, it's worth it!