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

From Laurent Martelli
Subject Re: Speeding up select distinct
Date
Msg-id 87br9j4f4d.fsf@stan.aopsys
Whole thread Raw
In response to Re: Speeding up select distinct  (Rod Taylor <pg@rbt.ca>)
Responses Re: Speeding up select distinct
List pgsql-performance
>>>>> "Rod" == Rod Taylor <pg@rbt.ca> writes:

  Rod> On Wed, 2005-03-16 at 18:58 +0100, Laurent Martelli wrote:
  >> Consider this query:
  >>
  >> SELECT distinct owner from pictures;

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

Yes, but I thought that an index might be able to know what distinct
values there are and help optime that query very much.

--
Laurent Martelli
laurent@aopsys.com                                Java Aspect Components
http://www.aopsys.com/                          http://jac.objectweb.org


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