Re: Too slow querying a table of 15 million records

Поиск
Список
Период
Сортировка
От John A Meinel
Тема Re: Too slow querying a table of 15 million records
Дата
Msg-id 42C0EF9B.3070308@arbash-meinel.com
обсуждение исходный текст
Ответ на Re: Too slow querying a table of 15 million records  (Tobias Brox <tobias@nordicbet.com>)
Список pgsql-performance
Tobias Brox wrote:

>[kjelle@bingon.no - Tue at 08:33:58PM +0200]
>
>
>>I use FreeBSD 4.11 with PostGreSQL 7.3.8.
>>
>>
>(...)
>
>
>>database=> explain select date_trunc('hour', time),count(*) as total from
>>test where p1=53 and time > now() - interval '24 hours' group by
>>date_trunc order by date_trunc ;
>>
>>
>
>I haven't looked through all your email yet, but this phenomena have been up
>at the list a couple of times.  Try replacing "now() - interval '24 hours'"
>with a fixed time stamp, and see if it helps.
>
>pg7 will plan the query without knowledge of what "now() - interval '24
>hours'" will compute to.  This should be fixed in pg8.
>
>
>
The grandparent was a mailing list double send. Notice the date is 1
week ago. It has already been answered (though your answer is still
correct).

John
=:->


Вложения

В списке pgsql-performance по дате отправления:

Предыдущее
От: Tom Lane
Дата:
Сообщение: Re: Poor index choice -- multiple indexes of the same columns
Следующее
От: Michael Fuhr
Дата:
Сообщение: Re: Postgresql7.4.5 running slow on plpgsql function