Re: preloading indexes - Mailing list pgsql-performance

From Mike Benoit
Subject Re: preloading indexes
Date
Msg-id 1099529442.18904.4.camel@ipso.snappymail.ca
Whole thread Raw
In response to Re: preloading indexes  (Tom Lane <tgl@sss.pgh.pa.us>)
List 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@opensourceonline.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@snappymail.ca>

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