On Wed, Apr 4, 2012 at 4:34 PM, Simon Riggs <simon@2ndquadrant.com> wrote:
> Interesting. You've spoken at length how this hardly ever happens and
> so this can't have any performance effect. That was the reason for
> kicking out my patch addressing clog history, wasn't it?
Uh, no, the reason for kicking out your clog history patch was that it
caused throughput to drop by a factor of 3 on a pgbench test at scale
factor 300. I assume you've got a bug there somewhere, or maybe
there's some other effect that hasn't been quantified.
> Why is this pgbench run accessing so much unhinted data that is > 1
> million transactions old? Do you believe those numbers? Looks weird.
Seems pretty normal to me, for the reasons Greg Stark states.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
