Re: Forcing use of a particular index

Поиск
Список
Период
Сортировка
От Jacques Caron
Тема Re: Forcing use of a particular index
Дата
Msg-id 6.2.0.14.0.20050628003823.065c2de8@pop.interactivemediafactory.net
обсуждение исходный текст
Ответ на Forcing use of a particular index  ("Karl O. Pinc" <kop@meme.com>)
Список pgsql-performance
Hi,

At 01:16 28/06/2005, Karl O. Pinc wrote:
>http://www.postgresql.org/docs/8.0/static/indexes-examine.html
>
>Says:
>
>"If you do not succeed in adjusting the costs to be more
>appropriate, then you may have to resort to forcing index
>usage explicitly."
>
>Is there a way to force a query to use a particular index?

Not that I know of.

>If not, what does this sentence mean?

That you can force the planner to use an index (any one) over not using an
index (and using seq scans instead) by setting enable_seqscan to off.

Jacques.



В списке pgsql-performance по дате отправления:

Предыдущее
От: Josh Berkus
Дата:
Сообщение: Re: Poor index choice -- multiple indexes of the same columns
Следующее
От: "Karl O. Pinc"
Дата:
Сообщение: Performance analysis of plpgsql code