What's faster?

Hello all!

I'm performing a query that returns me hundreds of records... but I
need cut them in pages that have 15 items! (using PHP)

So, is it faster:

select blablabal from _complex_query
if (count($result) > 15) show_pages;
show_only_15_rows($result);

or:

select count(*) from _complex_query
if ($result1 > 15) show_pages;
select blablabal from _complex_query LIMIT ... (see the LIMIT!)
show $result

On the first, I can use pg_num_rows instead of count(), too.

what do you think?

Thank you!