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Message Posted: Mon, 20 Jun 2011 @ 19:56:31 GMT


     
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Subj:   Re: Distinct vs. group by in TD 13 onwards
 
From:   Pluebell, Fred

Prior to TD13:

DISTINCT performs better when the results are already nearly unique (few duplicates are being eliminated).

GROUP BY will perform better when large numbers of duplicates are being eliminated.


Starting with TD13, the optimizer will cost the alternative strategies rather choosing based on the syntax used.



     
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