Re: Creating tons of tables to support a query

Поиск
Список
Период
Сортировка
От Jan Ploski
Тема Re: Creating tons of tables to support a query
Дата
Msg-id 12285029.1031529248654.JavaMail.jpl@remotejava
обсуждение исходный текст
Ответ на Creating tons of tables to support a query  (Jan Ploski <jpljpl@gmx.de>)
Ответы Re: Creating tons of tables to support a query  (Bruno Wolff III <bruno@wolff.to>)
Список pgsql-general
On Sun, Sep 08, 2002 at 06:51:55PM -0500, Bruno Wolff III wrote:
> On Sun, Sep 08, 2002 at 23:58:44 +0200,
>   Jan Ploski <jpljpl@gmx.de> wrote:
> >
> > select count(*) from message where sectionID = ? and dateSent > ?
>
> If the dateDent is the same for each query, you should probably be doing
> it in one query. Something like:
> select sectionID, count(*) from message where dateSent > ? group by sectionID

Bruno,

The dateSent is not same for each section, though it may be same
for several sections (in my app, sections belong to forums, and dateSent
is same for all sections of the same forum). Anyway, I would like to avoid
counting by traversing a huge number of rows, and I think it's what the
backend does behind the scenes for such a query.

-JPL


В списке pgsql-general по дате отправления:

Предыдущее
От: Jan Ploski
Дата:
Сообщение: Re: Creating tons of tables to support a query
Следующее
От: "Nathan Hopper"
Дата:
Сообщение: Using the right tool