Re: [PERFORM] Find original number of rows before applied LIMIT/OFFSET?

"D. Dante Lorenso" <dante(at)lorenso(dot)com> writes:

> Any thoughts? Sure, the PHP function I'm using above 'works', but is it
> the most efficient? I hope I'm not actually pulling all 100,000 records
> across the wire when I only intend to show 10 at a time. See what I'm
> getting at?

I tend to do it using a separate select count(*). My thinking is that the
count(*) query can be simplified and exclude things like the ORDER BY clause
and any select list entries that require extra work. It can often even exclude
whole joins.

By doing a separate query I can do that extra work only for the rows that i
actually need for display. Hopefully using an index to pull up those rows. And
do the count(*) in the most efficient way possible, probably a sequential scan
with no joins for foreign keys etc.

But I suspect the two methods both work out to suck about equally.

--
greg