FW: optimize query with a maximum(date) extraction

bad address kep his from going to the list on my first try ... apologies to the moderators.

-----Original Message-----
From: Gregory Williamson
Sent: Wed 9/5/2007 4:59 AM
To: JS Ubei; pgsql-performance(at)postgresql(dot)org
Subject: RE: [PERFORM] optimize query with a maximum(date) extraction

In order to help others help you, you might provide the following:

table description (columns, types, indexes) (\d tablename from psql does nicely)

the same query run as "EXPLAIN ANALYZE <your query here>;"

Greg Williamson
Senior DBA
GlobeXplorer LLC, a DigitalGlobe company

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-----Original Message-----
From: pgsql-performance-owner(at)postgresql(dot)org on behalf of JS Ubei
Sent: Wed 9/5/2007 3:53 AM
To: pgsql-performance(at)postgresql(dot)org
Subject: [PERFORM] optimize query with a maximum(date) extraction

Hi all,

I need to improve a query like :

SELECT id, min(the_date), max(the_date) FROM my_table GROUP BY id;

Stupidly, I create a B-tree index on my_table(the_date), witch is logically not used in my query, because it's not with a constant ? isn't it ?

I know that I can't create a function index with an aggregative function.

How I can do ?

thanks,

jsubei

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