Re: query optimization

Поиск
Список
Период
Сортировка
От Klint Gore
Тема Re: query optimization
Дата
Msg-id 487FD8A3.6080405@une.edu.au
обсуждение исходный текст
Ответ на query optimization  ("Kevin Duffy" <KD@wrinvestments.com>)
Ответы Re: query optimization  ("Kevin Duffy" <KD@wrinvestments.com>)
Список pgsql-general
Kevin Duffy wrote:
>
> So here are the questions for the PSQL gurus:
>
> Is getsectypekey(‘CFD’) executing for every join (or possible join)
> between positions_gsco and security?
>
> Causing a scan of security for every possible join.
>
> Does ‘ (select getsectypekey('CFD') ) ‘ cause the getsectype()
> function to be executed once and thus
>
> allowing the index on security to be used.
>
> And of couse ‘5’ makes things simple. The index on security is used.
>
> Am I posting this in the right. If not please help me correct my error
> and point me to the correct spot.
>

Is the function stable or volatile?

As Scott Marlowe suggested, you need to look at the explain results to
find out what the plan is in each case.

klint.

--
Klint Gore
Database Manager
Sheep CRC
A.G.B.U.
University of New England
Armidale NSW 2350

Ph: 02 6773 3789
Fax: 02 6773 3266
EMail: kgore4@une.edu.au


В списке pgsql-general по дате отправления:

Предыдущее
От: mikesdenning@gmail.com
Дата:
Сообщение: autovacuum logging 8.1
Следующее
От: Francisco Reyes
Дата:
Сообщение: Reducing memory usage of insert into select operations?