Re: Select query ignores index on large table

Поиск
Список
Период
Сортировка
От hubert depesz lubaczewski
Тема Re: Select query ignores index on large table
Дата
Msg-id 20110127141245.GD15777@depesz.com
обсуждение исходный текст
Ответ на Select query ignores index on large table  (Michael Kemanetzis <michael.kemanetzis@gmail.com>)
Ответы Re: Select query ignores index on large table
Список pgsql-general
On Thu, Jan 27, 2011 at 04:04:02PM +0200, Michael Kemanetzis wrote:
> Hello, I'm experiencing a strange behavior running a simple select query on
> a table that has about 12 million rows. Specifically, changing the "LIMIT"
> value seems to change the execution plan but the result in one of the cases
> is unjustifiably slow, as if it ignores all indexes.
>
> The table structure, the queries used and the results are here:
> http://pastebin.com/fn36BuKs
>
> Is there anything I can do to improve the speed of this query?

create index qq on vehicleevent (veh_id, event_id)
could help.

Best regards,

depesz

--
Linkedin: http://www.linkedin.com/in/depesz  /  blog: http://www.depesz.com/
jid/gtalk: depesz@depesz.com / aim:depeszhdl / skype:depesz_hdl / gg:6749007

В списке pgsql-general по дате отправления:

Предыдущее
От: Michael Kemanetzis
Дата:
Сообщение: Select query ignores index on large table
Следующее
От: Sim Zacks
Дата:
Сообщение: Re: Queyring for columns which are exist in table.