On Thu, May 31, 2012 at 9:17 AM, Robert Haas <robertmh...@gmail.com> wrote: > > Oh, ho. So from this we can see that the problem is that we're > getting huge amounts of spinlock contention when pinning and unpinning > index pages. > > It would be nice to have a self-contained reproducible test case for > this, so that we could experiment with it on other systems.
I just posted a patch under subject "pgbench--new transaction type" that introduces a pgbench -P option. I think that that would do a good job of simulating unique-key look-ups on the inner side of a nested loop (which is basically what we have here) and so creating contention on index pages. Right now I don't have anything with more than 2 CPUs and 2 is not high enough to get much contention so I can't post any meaningful numbers. (pgbench -P might also be of interest in hash index investigation) Cheers, Jeff -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
