MySQL Forums
Forum List  »  Optimizer & Parser

Re: Query not always using indexes
Posted by: Peter Brawley
Date: January 06, 2017 12:28PM

In the slow run, ref=ALL means the optimiser could not find an `sch` index that would be faster than a table scan. To have a chance at suggesting an improvement, we'd need to see the two update queries and Show Create Table results for the referenced tables.

Options: ReplyQuote


Subject
Views
Written By
Posted
2500
January 06, 2017 05:48AM
Re: Query not always using indexes
825
January 06, 2017 12:28PM
906
January 09, 2017 05:18AM


Sorry, you can't reply to this topic. It has been closed.

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.