Re: Speeding up select distinct - Mailing list pgsql-performance

From Rod Taylor
Subject Re: Speeding up select distinct
Date
Msg-id 1110996623.1132.244.camel@home
Whole thread Raw
In response to Speeding up select distinct  (Laurent Martelli <laurent@aopsys.com>)
Responses Re: Speeding up select distinct  (Laurent Martelli <laurent@aopsys.com>)
List pgsql-performance
On Wed, 2005-03-16 at 18:58 +0100, Laurent Martelli wrote:
> Consider this query:
>
> SELECT distinct owner from pictures;

The performance has nothing to do with the number of rows returned, but
rather the complexity of calculations and amount of data to sift through
in order to find it.

> Any ideas, apart from more or less manually maintaining a list of
> distinct owners in another table ?

This would be the proper thing to do, along with adding a foreign key
from pictures to the new owner structure for integrity enforcement.
--


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