Pushing LIMIT into sub-queries of a UNION ALL? - Mailing list pgsql-performance

From Dave Johansen
Subject Pushing LIMIT into sub-queries of a UNION ALL?
Date
Msg-id BANLkTi=XnAaiiCA=5hbX1Sg6jCDQ6ZmChA@mail.gmail.com
Whole thread Raw
Responses Re: Pushing LIMIT into sub-queries of a UNION ALL?
List pgsql-performance
I am using Postgres 8.3 and I have an issue very closely related to the one described here:
http://archives.postgresql.org/pgsql-general/2005-06/msg00488.php

Basically, I have a VIEW which is a UNION ALL of two tables but when I do a select on the view using a LIMIT, it scans the entire tables and takes significantly longer than writing out the query with the LIMITs in the sub-queries themselves. Is there a solution to get the view to perform like the sub-query version?

Thanks,
Dave

pgsql-performance by date:

Previous
From: Andrey Vorobiev
Date:
Subject: Performance degradation of inserts when database size grows
Next
From: STA
Date:
Subject: Re: Modifying shared_buffers causes despite plenty of ram