On Thu, 2006-06-08 at 10:27 -0400, Tom Lane wrote: > Simon Riggs <[EMAIL PROTECTED]> writes: > > On Wed, 2006-06-07 at 17:28 -0400, Tom Lane wrote: > >> The overhead seems to be on the order of a couple tens of percent usually. > >> I don't see how that makes the difference between an EXPLAIN ANALYZE you > >> can run and one you can't. > > > Well, thats not my experience and doesn't match others posted on > > -hackers. > > > A simple test with pgbench shows the timing overhead of EXPLAIN ANALYZE > > to be consistently above 500% (or more than +400%, depending upon how > > you style those numbers). > > I think we ought to find out why your machine is so broken.
> I'm too lazy to pull up any of my other machines right now, but this is > generally consistent with my experience ever since EXPLAIN ANALYZE was > written. Great. Well it isn't consistent with mine, or others who've posted to this list. > So: what's your platform exactly? FC5, Intel laptop running cvstip, new in January. But thats irrelevant. I'm not a user, I solve others problems, as you know. Hence my interest in a usable tool to do that. So far we have myself, Kevin, Martijn and Luke all saying there is a distortion or a massive overhead caused by EXPLAIN ANALYZE. http://archives.postgresql.org/pgsql-hackers/2006-03/msg00954.php http://archives.postgresql.org/pgsql-patches/2006-05/msg00168.php It's real. I won't press the point further. -- Simon Riggs EnterpriseDB http://www.enterprisedb.com ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings
