Re: Index on a NULL-value

От: Tobias Brox
Тема: Re: Index on a NULL-value
Дата: ,
Msg-id: 20050531033158.GI26100@tobias.exoweb.net
(см: обсуждение, исходный текст)
Ответ на: Re: Index on a NULL-value  (Bruno Wolff III)
Ответы: Re: Index on a NULL-value  (Bruno Wolff III)
Список: pgsql-performance

Скрыть дерево обсуждения

Index on a NULL-value  (Tobias Brox, )
 Re: Index on a NULL-value  (Bruno Wolff III, )
  Re: Index on a NULL-value  (Tobias Brox, )
   Re: Index on a NULL-value  (Bruno Wolff III, )
 Re: Index on a NULL-value  (Tobias Brox, )
  Re: Index on a NULL-value  (Bruno Wolff III, )
   Re: Index on a NULL-value  (Tobias Brox, )
    Re: Index on a NULL-value  (Greg Stark, )
     Re: Index on a NULL-value  (Tom Lane, )
   Re: Index on a NULL-value  (Tom Lane, )
    Re: Index on a NULL-value  (Tobias Brox, )
 Re: Index on a NULL-value  (Tobias Brox, )

[Tobias Brox]
> test=# set enable_seqscan=off;

[Bruno Wolff III - Mon at 10:16:53PM -0500]
> It isn't surprising that an index wasn't used since a sequential scan is
> going to be faster in your test case.
>
> If you want to test this out, you to want use realistically sized tables.

Wrong.  In this case I was not wondering about the planners choise of not
using the index, but the fact that the planner could not find the index at
all.  Reproducing it on a simple table in a test environment was a valid
strategy to solve this specific problem.

--
Tobias Brox, Beijing


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