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Re: Slow query
Posted by: Peter Brawley
Date: December 11, 2015 05:00PM

What version of MySQL?

Exists( Select ... ) can be slow.

OR in the Where clause may not optimise well, depending on the engine and the version.

If you don't get satisfactoty results from changing In(Select...) to Join, and writing the two queries as Unions rather than Ors, post the Explain Extended results, Show Create Table results (not Describe!) and Show Tabke Status results for each table

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