Re: Optimize query for listing un-read messages - Mailing list pgsql-performance

From David G Johnston
Subject Re: Optimize query for listing un-read messages
Date
Msg-id 1398979195531-5802157.post@n5.nabble.com
Whole thread Raw
In response to Optimize query for listing un-read messages  (Andreas Joseph Krogh <andreas@visena.com>)
Responses Re: Optimize query for listing un-read messages  (Andreas Joseph Krogh <andreas@visena.com>)
List pgsql-performance
How does something like:

WITH unreads AS (
SELECT messageid FROM message
EXCEPT
SELECT messageid FROM message_property WHERE personid=1 AND has_read
)
SELECT ...
FROM unreads
JOIN messages USING (messageid)
;

perform?

David J.




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