Re: Optimizing a request

On Tue, 31 Aug 2004 21:16:46 +0100, Gary Doades <gpd(at)gpdnet(dot)co(dot)uk> wrote:

> I can only presume you mean 1 GB RAM. What exactly are your
> settings for shared buffers and effective_cache_size?

for 1 GB RAM,
shared_buffers = 65536
effective_cache_size = 16384

>
> Can you increase default_statistics_target and re-test? It is possible
> that with such a large table that the distribution of values is skewed and
> postgres does not realise that an index scan would be better.

OK, tomorrow, I'll try with the new value of default_statistics_target

> It seems very odd otherwise that only on row out of 10,000,000 could
> match and postgres does not realise this.
>
> Can you post an explain analyse (not just explain) for this query?

yes, of course

--
Jean-Max Reymond
CKR Solutions
http://www.ckr-solutions.com