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Message Posted: Thu, 23 Apr 2015 @ 12:48:37 GMT


     
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Subj:   Re: Impact of using NOT IN vs AND condition
 
From:   Dave Wellman

Hi,

If the explain plans are the same then performance will be the same.

Where have you read or in what context have you been told that "not in" should be avoided in queries? The most obvious / common place where there might be an issue with "not in" is when using a sub-query that may return a NULL 'row'. In this case you will always get 0 rows back from the query. (And if you are seeing the "AND" and "NOT IN" queries generating the same explain plan then I think it unlikely that you are using a sub-query).

Whether the plan shows an FTS or indexed access to a table is probably nothing to do with NOT IN or multiple AND'd conditions.


Cheers,

Dave

Ward Analytics Ltd - Information in motion (www.ward-analytics.com)



     
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