Re: "nice"/low priority Query

On Tue, Aug 02, 2005 at 12:19:30PM -0400, Tom Lane wrote:
> Tobias Brox <tobias@nordicbet.com> writes:
> > Is there any ways to give postgresql a hint that a
> > particular SQL call should be run at lower priority?  Since every db
> > connection has a pid, I can manually run "renice" to scheduele it by the OS
> > - but of course I can't do it manually all the time.
>
> And it won't help you anyway, because renice only affects CPU priority
> not I/O scheduling ... which, by your description, is the real problem.

Actually, from what I've read 4.2BSD actually took priority into account
when scheduling I/O. I don't know if this behavior is still present in
FreeBSD or the like, though. So depending on the OS, priority could play
a role in determining I/O scheduling.
--
Jim C. Nasby, Database Consultant               decibel@decibel.org
Give your computer some brain candy! www.distributed.net Team #1828

Windows: "Where do you want to go today?"
Linux: "Where do you want to go tomorrow?"
FreeBSD: "Are you guys coming, or what?"