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RE: optimize hash join between 2 large tables

From: Christian Antognini <Christian.Antognini_at_trivadis.com>
Date: Fri, 21 Jan 2005 16:28:08 +0100
Message-ID: <2CF83791A616BB4DA203FFD13007824A01E6B269@MSXVS02.trivadis.com>


Hi Paula

>Other then use sort_area_size to sort in memory and parallel query what
>can be done to optimize a pull of 2 large tables joined together where
>most of the rows from both tables are selected???

First of all a hash join use the memory that is configured via = hash_area_size and not sort_area_size.

A possibility to further speed up joins (in addition to memory and PX) = is to use partition-wise joins. In the tuning guide you find information = about it. Notice that to take out the max, the execution of a = partition-wise join should be parallelized.

HTH
Chris

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Received on Fri Jan 21 2005 - 10:39:48 CST

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