Re: How to optimize select count(*)..group by?

David Fetter wrote:
> On Thu, Jul 28, 2005 at 09:19:49AM -0700, Bryan Field-Elliot wrote:
>
>>We have this simple query:
>>
>>select status, count(*) from customer group by status;
>>
>>There is already a btree index on status, but, the customer table is
>>huge, and this query must be executed very frequently... an
>>"explain" on this query shows that it is quite costly (and we notice
>>it runs slowly)...
>>
>>Can someone recommend the best technique to optimize this? We can
>>create new indices, we can re-write this query.. But we'd rather not
>>add new tables or columns if possible (not just to solve this
>>problem).
>
>
> You're pretty much stuck with either writing triggers that modify a
> cache table or having your performance the way it is now.
>
> Cheers,
> D
How about the new bitmap index? I wonder if that'll result in better performance
for that type of query?

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