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Re: Difference execution plans for same query
Posted by: Peter Brawley
Date: February 25, 2016 01:51AM

It's a weakness of the MyISAM engine. Two possible remedies: switch to InnoDB, which doesn't depend on Analyze Table, or add Force Index clauses to the query.

BTW the query contains a serious inconsistency: select * ... group by sfol.item_id entails that all returned values for * except sfol.item_id will be arbitrary unless every one of those column values is unique per sfol.item_id. If that's the case, the Group By clause is superfluous.

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Re: Difference execution plans for same query
February 25, 2016 01:51AM

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