Mark Wong wrote: > On Thu, Nov 13, 2008 at 11:53 AM, Tom Lane <[EMAIL PROTECTED]> wrote: > > Heikki Linnakangas <[EMAIL PROTECTED]> writes: > >> A lot of people have suggested raising our default_statistics target, > >> and it has been rejected because there's some O(n^2) behavior in the > >> planner, and it makes ANALYZE slower, but it's not that crazy. > > > > I think everyone agrees it ought to be raised. Where the rubber meets > > the road is deciding just *what* to raise it to. We've got no > > convincing evidence in favor of any particular value. > > > > If someone actually wanted to put some effort into this, I'd suggest > > taking some reasonably complex benchmark (maybe TPCH or one of the DBT > > series) and plotting planner runtime for each query as a function of > > statistics_target, taking care to mark the breakpoints where it shifted > > to a better (or worse?) plan due to having better stats. > > Almost there... I have a MSA70 plugged into the DL380 I have from HP > and I'm trying to find time to get my scripts updated to deal with how > tools have changed over the years... I'm updating the DBT-2 (tpc-c > kit) I have first
Yes, please test something. I am tired if us saying we need to increase default_statistics_target, but because we don't know the magic number, we do nothing release after release. -- Bruce Momjian <[EMAIL PROTECTED]> http://momjian.us EnterpriseDB http://enterprisedb.com + If your life is a hard drive, Christ can be your backup. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
