On Wed, Feb 1, 2012 at 12:48 PM, Alessandro Gagliardi
<alessandro@path.com> wrote:
> LIMIT 65536; Total query runtime: 14846 ms.
> - http://explain.depesz.com/s/I3E
> LIMIT 69632: Total query runtime: 80141 ms.
> - http://explain.depesz.com/s/9hp
>
> So it looks like when the limit crosses a certain threshold (somewhere north
> of 2^16), Postgres decides to do a Seq Scan instead of an Index Scan.
> I've already lowered random_page_cost to 2. Maybe I should lower it to 1.5?
> Actually 60K should be plenty for my purposes anyway.
also, is effective_cache_size set to a reasonable value?
merlin