On Thu, Feb 25, 2010 at 6:42 PM, Bruce Momjian <bruce@xxxxxxxxxx> wrote: > Was there every any conclusion on this issue? I don't think so. ...Robert > --------------------------------------------------------------------------- > > Matthew Wakeling wrote: >> >> Revisiting the thread a month back or so, I'm still investigating >> performance problems with GiST indexes in Postgres. >> >> Looking at http://wiki.postgresql.org/wiki/PostgreSQL_8.4_Open_Items I'd >> like to clarify the contrib/seg issue. Contrib/seg is vulnerable to >> pathological behaviour which is fixed by my second patch, which can be >> viewed as complete. Contrib/cube, being multi-dimensional, is not affected >> to any significant degree, so should not need alteration. >> >> A second quite distinct issue is the general performance of GiST indexes >> which is also mentioned in the old thread linked from Open Items. For >> that, we have a test case at >> http://archives.postgresql.org/pgsql-performance/2009-04/msg00276.php for >> btree_gist indexes. I have a similar example with the bioseg GiST index. I >> have completely reimplemented the same algorithms in Java for algorithm >> investigation and instrumentation purposes, and it runs about a hundred >> times faster than in Postgres. I think this is a problem, and I'm willing >> to do some investigation to try and solve it. >> >> Do you have a recommendation for how to go about profiling Postgres, what >> profiler to use, etc? I'm running on Debian Linux x86_64. >> >> Matthew >> >> -- >> Jadzia: Don't forget the 34th rule of acquisition: Peace is good for business. >> Quark: That's the 35th. >> Jadzia: Oh yes, that's right. What's the 34th again? >> Quark: War is good for business. It's easy to get them mixed up. >> >> -- >> Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) >> To make changes to your subscription: >> http://www.postgresql.org/mailpref/pgsql-performance > > -- > Bruce Momjian <bruce@xxxxxxxxxx> http://momjian.us > EnterpriseDB http://enterprisedb.com > PG East: http://www.enterprisedb.com/community/nav-pg-east-2010.do > + If your life is a hard drive, Christ can be your backup. + > > -- > Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-performance > -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
