Pushing LIMIT into sub-queries of a UNION ALL?

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От Dave Johansen
Тема Pushing LIMIT into sub-queries of a UNION ALL?
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Msg-id BANLkTi=XnAaiiCA=5hbX1Sg6jCDQ6ZmChA@mail.gmail.com
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Ответы Re: Pushing LIMIT into sub-queries of a UNION ALL?  (Robert Klemme <shortcutter@googlemail.com>)
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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

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