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Message Posted: Wed, 07 Oct 2009 @ 08:38:19 GMT


     
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Subj:   Skewness problem in query.
 
From:   Anomy Anom

<-- Anonymously Posted: Wednesday, October 07, 2009 03:52 -->

Hi Folks,

There are two tables A & B which have unique PI and data distribution across the AMPs is perfect, no skewness.

But we have a column, say colx (not part of PI), on which we have to join these tables. Table A has around half of values of colx as default value (say 999) (no of records having this value are around 1 million ). And table B has just one value as 999 for this joining column colx.

So when tables are joined on colx, there is going to be high skewness during join as all these one million rows are gonig to be on same AMP.

After this join we have a agregation in the same query.

This is causing out of spool space error.

Can there be any solution for this.


regards



     
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