Re: getting count for a specific querry

Ragnar =?ISO-8859-1?Q?Hafsta=F0?= <gnari(at)simnet(dot)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? But otherwise, yeah,
this is a popular solution for paging through some rows. Doesn't really
help with the problem of counting the total dataset though ...

regards, tom lane