Re: Use of multipart index with "IN"

От: Tom Lane
Тема: Re: Use of multipart index with "IN"
Дата: ,
Msg-id: 400.1067275029@sss.pgh.pa.us
(см: обсуждение, исходный текст)
Ответ на: Use of multipart index with "IN"  (Rob Messer)
Список: pgsql-performance

Скрыть дерево обсуждения

Moving postgresql.conf tunables into 2003...  (Sean Chittenden, )
 Re: Moving postgresql.conf tunables into 2003...  (Rod Taylor, )
  Re: Moving postgresql.conf tunables into 2003...  (Sean Chittenden, )
 Re: Moving postgresql.conf tunables into 2003...  ("scott.marlowe", )
  Re: Moving postgresql.conf tunables into 2003...  (Brian Hirt, )
   Re: Moving postgresql.conf tunables into 2003...  (Sean Chittenden, )
    Re: Moving postgresql.conf tunables into 2003...  (Matthew Hixson, )
  Re: Moving postgresql.conf tunables into 2003...  (Sean Chittenden, )
   Re: Moving postgresql.conf tunables into 2003...  (Tom Lane, )
    Re: Moving postgresql.conf tunables into 2003...  (Sean Chittenden, )
 Re: Moving postgresql.conf tunables into 2003...  ("Michael Mattox", )
  Re: Moving postgresql.conf tunables into 2003...  (Sean Chittenden, )
   Re: Moving postgresql.conf tunables into 2003...  (Martin Foster, )
   Re: Moving postgresql.conf tunables into 2003...  (Bruce Momjian, )
 Re: Moving postgresql.conf tunables into 2003...  (Ron, )
 Re: Moving postgresql.conf tunables into 2003...  (Tom Lane, )
  Re: Moving postgresql.conf tunables into 2003...  (Sean Chittenden, )
   Re: Moving postgresql.conf tunables into 2003...  (Rod Taylor, )
   Re: Moving postgresql.conf tunables into 2003...  (Manfred Koizar, )
    Re: Moving postgresql.conf tunables into 2003...  (Sean Chittenden, )
     Re: Moving postgresql.conf tunables into 2003...  (Manfred Koizar, )
      Re: Moving postgresql.conf tunables into 2003...  (Sean Chittenden, )
       Re: Moving postgresql.conf tunables into 2003...  (Tom Lane, )
        Index correlation (was: Moving postgresql.conf tunables into 2003... )  (Manfred Koizar, )
     Use of multipart index with "IN"  (Rob Messer, )
      Re: Use of multipart index with "IN"  (Tom Lane, )
 Re: Moving postgresql.conf tunables into 2003...  (Josh Berkus, )
  Re: Moving postgresql.conf tunables into 2003...  (Tom Lane, )
  Re: Moving postgresql.conf tunables into 2003...  (Tom Lane, )
  Re: Moving postgresql.conf tunables into 2003...  (Tom Lane, )
  Re: Moving postgresql.conf tunables into 2003...  (Sean Chittenden, )
   Re: Moving postgresql.conf tunables into 2003...  (Josh Berkus, )
    Re: Moving postgresql.conf tunables into 2003...  (Sean Chittenden, )
     Re: Moving postgresql.conf tunables into 2003...  (Josh Berkus, )
   Re: Moving postgresql.conf tunables into 2003...  ("Matthew Nuzum", )
    Re: Moving postgresql.conf tunables into 2003...  (Michael Pohl, )
     Re: Moving postgresql.conf tunables into 2003...  (Martin Foster, )
     Re: Moving postgresql.conf tunables into 2003...  (Bruce Momjian, )
    Re: Moving postgresql.conf tunables into 2003...  (Chris Travers, )
     Re: Moving postgresql.conf tunables into 2003...  ("Jim C. Nasby", )
   Re: Moving postgresql.conf tunables into 2003...  (Andrew Sullivan, )
    Re: Moving postgresql.conf tunables into 2003...  ("Matthew Nuzum", )
     Re: Moving postgresql.conf tunables into 2003...  ("Michael Mattox", )
     Re: Moving postgresql.conf tunables into 2003...  (Tom Lane, )
      Re: Moving postgresql.conf tunables into 2003...  (Kaarel, )
       Re: Moving postgresql.conf tunables into 2003...  ("scott.marlowe", )
        Re: Moving postgresql.conf tunables into 2003...  (Martin Foster, )
  Re: Moving postgresql.conf tunables into 2003...  ("Matthew Nuzum", )

Rob Messer <> writes:
> The problem comes in when we are selecting multiple field_name values
> in one query.  The normal SQL syntax we have been using is like this:

> select field_name, option_tag from ds_rec_fld where recid = 3001 and
> field_name in ('Q3A1', 'Q3A9');

You'd have better luck if field_name were the first column of the
two-column index.  See the archives.

Improving this situation is on the to-do list but it seems not trivial
to fix.

            regards, tom lane


В списке pgsql-performance по дате сообщения:

От: Tom Lane
Дата:
Сообщение: Re: Very Poor Insert Performance
От: Josh Berkus
Дата:
Сообщение: Guesses on what this NestLoop is for?