От: Matthew Wakeling
Тема: GiST index performance
Дата: ,
Msg-id: alpine.DEB.1.10.0906041702320.4147@aragorn.flymine.org
(см: обсуждение, исходный текст)
Ответы: Re: GiST index performance  (Robert Haas)
Re: GiST index performance  (Bruce Momjian)
Список: pgsql-performance

Скрыть дерево обсуждения

GiST index performance  (Matthew Wakeling, )
 Re: GiST index performance  (Robert Haas, )
  Re: GiST index performance  (Matthew Wakeling, )
   Re: GiST index performance  (Tom Lane, )
    Re: GiST index performance  (Matthew Wakeling, )
     Re: GiST index performance  (Tom Lane, )
      Re: GiST index performance  (Matthew Wakeling, )
       Re: GiST index performance  (Tom Lane, )
        Re: GiST index performance  (Matthew Wakeling, )
         Re: GiST index performance  (Matthew Wakeling, )
          Re: GiST index performance  (Matthew Wakeling, )
           Re: GiST index performance  (Tom Lane, )
           Re: GiST index performance  (Adam Gundy, )
        Re: GiST index performance  (Heikki Linnakangas, )
      Re: GiST index performance  (Greg Smith, )
       Re: GiST index performance  (Robert Haas, )
 Re: GiST index performance  (Bruce Momjian, )
  Re: GiST index performance  (Robert Haas, )
  Re: GiST index performance  (Matthew Wakeling, )
   Re: GiST index performance  (Robert Haas, )
   Re: GiST index performance  (Yeb Havinga, )
    Re: GiST index performance  (Yeb Havinga, )
     Re: GiST index performance  (Yeb Havinga, )
      Re: GiST index performance  (Yeb Havinga, )
       Re: GiST index performance  (Yeb Havinga, )
        Re: GiST index performance  (Kenneth Marshall, )
         Re: GiST index performance  (Yeb Havinga, )
          Re: GiST index performance  (Matthew Wakeling, )
           Re: GiST index performance  (Yeb Havinga, )
            Re: GiST index performance  (Matthew Wakeling, )

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.


В списке pgsql-performance по дате сообщения:

От: "Kevin Grittner"
Дата:
Сообщение: Re: Scalability in postgres
От: "Kevin Grittner"
Дата:
Сообщение: Re: Scalability in postgres