Re: Vacuum thoughts

Neil Conway <neilc@samurai.com>

From: Neil Conway <neilc@samurai.com>
To: Greg Stark <gsstark@mit.edu>
Cc: PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2003-10-17T20:48:31Z
Lists: pgsql-hackers
On Fri, 2003-10-17 at 16:22, Greg Stark wrote:
> If it's just a matter of all the read i/o from vacuum then we're best off
> sleeping for a few milliseconds every few kilobytes. If it's the cache then
> we're probably better off reading a few megabytes and then sleeping for
> several seconds to allow the other buffers to get touched and pushed back to
> the front of the LRU.

Uh, no -- if it is the cache, we're better off fixing the buffer
replacement policy, not trying to hack around it. Replacement policies
that don't suffer from sequential flooding are well known.

-Neil