Re: Improving Inner Join Performance

Поиск
Список
Период
Сортировка
От Frank Wiles
Тема Re: Improving Inner Join Performance
Дата
Msg-id 20060105132006.19c7cd31.frank@wiles.org
обсуждение исходный текст
Ответ на Improving Inner Join Performance  ("Andy" <frum@ar-sd.net>)
Список pgsql-performance
On Thu, 5 Jan 2006 17:16:47 +0200
"Andy" <frum@ar-sd.net> wrote:

> Hi to all,
>
> I have the following query:
>
> SELECT count(*) FROM orders o
>       INNER JOIN report r ON r.id_order=o.id
>       WHERE o.id_status>3

> How can I improve this query's performace?? The ideea is to count all
> the values that I have in the database for the following conditions.
> If the users puts in some other search fields on the where then the
> query runs faster but in this format sometimes it takes a lot lot of
> time(sometimes even 2,3 seconds).
>
> Can this be tuned somehow???

  Do you have an index on report.id_order ? Try creating an index for
  it if not and run a vacuum analyze on the table to see if it gets
  rid of the sequence scan in the plan.

 ---------------------------------
   Frank Wiles <frank@wiles.org>
   http://www.wiles.org
 ---------------------------------


В списке pgsql-performance по дате отправления:

Предыдущее
От: Markus Schaber
Дата:
Сообщение: Re: What's the best hardver for PostgreSQL 8.1?
Следующее
От: "Qingqing Zhou"
Дата:
Сообщение: Re: Help in avoiding a query 'Warm-Up' period/shared buffer cache