From: | Mike Benoit <ipso(at)snappymail(dot)ca> |
---|---|
To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
Cc: | stuff(at)opensourceonline(dot)com, pgsql-performance(at)postgresql(dot)org |
Subject: | Re: preloading indexes |
Date: | 2004-11-04 00:50:42 |
Message-ID: | 1099529442.18904.4.camel@ipso.snappymail.ca |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-performance |
If your running Linux, and kernel 2.6.x, you can try playing with the:
/proc/sys/vm/swappiness
setting.
My understanding is that:
echo "0" > /proc/sys/vm/swappiness
Will try to keep all in-use application memory from being swapped out
when other processes query the disk a lot.
Although, since PostgreSQL utilizes the disk cache quite a bit, this may
not help you.
On Wed, 2004-11-03 at 15:53 -0500, Tom Lane wrote:
> <stuff(at)opensourceonline(dot)com> writes:
> > The caching appears to disappear overnight.
>
> You've probably got cron jobs that run late at night and blow out your
> kernel disk cache by accessing a whole lot of non-Postgres stuff.
> (A nightly disk backup is one obvious candidate.) The most likely
> solution is to run some cron job a little later to exercise your
> database and thereby repopulate the cache with Postgres files before
> you get to work ;-)
>
> regards, tom lane
>
> ---------------------------(end of broadcast)---------------------------
> TIP 9: the planner will ignore your desire to choose an index scan if your
> joining column's datatypes do not match
--
Mike Benoit <ipso(at)snappymail(dot)ca>
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