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Message Posted: Sat, 14 Jan 2012 @ 22:41:21 GMT

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Subj:   Solutions to Data Skewing
From:   Anomy Anom

<-- Anonymously Posted: Saturday, January 14, 2012 17:21 -->


I wondered what solutions might? be extant for 'real' data that has skewed.

Consider this data distribution

     Value       count (*)

     2323232     12 million

     3545        120K

     34349       450K

     3434        45K    etc

If we had skewing caused by NULLS and 'default data' values we can perhaps try some random number solns to make it look better, on a join column.

What about 'real' data? ( the same column is joined and selected ) that causes 'lumpy' distribution causing rowhashes to run amuck when that data get hashed , causing skewed CPU, increasing Impact values and degrading performance .

Thank You

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