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Re: select distinct slower in 5.0 than 4.1
Posted by: KimSeong Loh
Date: December 27, 2005 06:49PM

If you already have a unique constraint on (pid,lastname), is there a need of the distinct in your select when you have a where condition with = on the lastname?
The distinct seems to be redundant and it makes MySQL do extra work to check for duplicates when there will not be any.

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