Re: getting count for a specific querry

Поиск
Список
Период
Сортировка
От Ragnar Hafstað
Тема Re: getting count for a specific querry
Дата
Msg-id 1112979349.7447.42.camel@localhost.localdomain
обсуждение исходный текст
Ответ на Re: getting count for a specific querry  (Tom Lane <tgl@sss.pgh.pa.us>)
Список pgsql-sql
On Fri, 2005-04-08 at 12:32 -0400, Tom Lane wrote:
> Ragnar Hafstað <gnari@simnet.is> writes:
> > you might reduce the performance loss if your dataset is ordered by
> > a UNIQUE index.
> 
> > select * from mytable where somecondition 
> >                       ORDER by uniquecol limit 50;
> 
> > and next:
> 
> > select * from mytable where somecondition AND uniquecol>? 
> >                       ORDER by uniquecol limit 50 OFFSET 50;
> 
> > where the ? is placeholder for last value returned by last query.
> 
> Uh, you don't want the OFFSET there do you? 

ooops! of course not. the uniquecol>? is meant to REPLACE
the OFFSET.

gnari




В списке pgsql-sql по дате отправления:

Предыдущее
От: Rod Taylor
Дата:
Сообщение: Re: getting count for a specific querry
Следующее
От: "Joel Fradkin"
Дата:
Сообщение: Re: getting count for a specific querry