Re: Pagination - 1 or 2 queries?
От | scott.marlowe |
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Тема | Re: Pagination - 1 or 2 queries? |
Дата | |
Msg-id | Pine.LNX.4.33.0309050837300.30535-100000@css120.ihs.com обсуждение исходный текст |
Ответ на | Pagination - 1 or 2 queries? (CSN <cool_screen_name90001@yahoo.com>) |
Ответы |
Re: Pagination - 1 or 2 queries?
Re: Pagination - 1 or 2 queries? |
Список | pgsql-general |
On Fri, 5 Sep 2003, CSN wrote: > Since you usually need to know the total number of > rows a query would return, do you think it's better > to: > > a) Do one query with a LIMIT and OFFSET to get the > results, and another COUNT query to get the total > number of rows? > > b) Do a single query without a LIMIT and OFFSET, then > do a seek or similiar to get at the rows you want? > > Most tutorials, code, etc. I've seen do "a". The > eclipse library does "b". Either way works. Does the eclipse library use a cursor, or grab the whole dataset and then seek on the client side? If it uses a cursor, I'd expect it to be the fastest and simplest implementation. Since a lot of libs are designed to work with MySQL, they often are written in the first method, where select count(*) is quite quick on MySQL, and MySQL doesn't have cursor support. With Postgresql, the cursor is likely to be the faster method.
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