Re: select question

Tom Lane writes:
> g <brian(at)wuwei(dot)govshops(dot)com> writes:
> > Use the limit clause.
> > SELECT message_text FROM messages ORDER BY creation_date LIMIT $limit,
> > $offset.
>
> > LIMIT 10, 0 gets you the first batch.
> > LIMIT 10, 10 gets you the second batch.
> > LIMIT 10, 20 gets you the third, etc.
>
> BTW, a little tip that a number of people have gotten burnt by not
> knowing: when you do this you *must* use an ORDER BY clause that's
> strong enough to order the result rows completely. Otherwise you
> are asking for slices out of an undefined ordering of the rows.
> You could get a different ordering on each request, leading to
> inconsistent slices --- in other words, missing or repeated rows.
>
> This does actually happen in Postgres 7.0, because the planner
> optimizes queries with small limit+offset differently from those
> without.
>
> regards, tom lane

Hi, I wonder if one must activate the LIMIT clause somewhere, bacause
for me it does nothing.

I'm using postgresql Version: 7.0.2 in a Debina potato system.

Thanx.

--
______________________________________________________

Felipe Alvarez Harnecker. QlSoftware.

Tel. 09.874.60.17 e-mail: felipe(dot)alvarez(at)qlsoft(dot)cl

Potenciado por Debian GNU/Linux http://www.qlsoft.cl/
______________________________________________________