From: Benjamin Arai <me@benjaminarai.com>
To: pgsql-performance@postgresql.org
To: pgsql-general@postgresql.org
Subject: Parrallel query execution for UNION ALL Queries
Date: Wed, 18 Jul 2007 09:14:35 -0700 (PDT)
Message-ID: <39160.131.107.65.118.1184775275.squirrel@webmail.benjaminarai.com> (raw)
Hi,
If I have a query such as:
SELECT * FROM (SELECT * FROM A) UNION ALL (SELECT * FROM B) WHERE
blah='food';
Assuming the table A and B both have the same attributes and the data
between the table is not partitioned in any special way, does Postgresql
execute WHERE blah="food" on both table simultaiously or what? If not, is
there a way to execute the query on both in parrallel then aggregate the
results?
To give some context, I have a very large amount of new data being loaded
each week. Currently I am partitioning the data into a new table every
month which is working great from a indexing standpoint. But I want to
parrallelize searches if possible to reduce the perofrmance loss of having
multiple tables.
Benjamin
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To: pgsql-performance@postgresql.org
Cc: me@benjaminarai.com, pgsql-general@postgresql.org
Subject: Re: Parrallel query execution for UNION ALL Queries
In-Reply-To: <39160.131.107.65.118.1184775275.squirrel@webmail.benjaminarai.com>
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