MySQL Forums
Forum List  »  InnoDB

Re: why must i specify an index in query?
Posted by: Peter Brawley
Date: July 03, 2015 03:06PM

If it needs to read data from the table, and Left Join requires that it read all rows, it may decide the index isn't worth it.

We could chase down the complexities of the original convoluted query, but we'd need Show Create Table results for usersmobile as well as enough Inserts for each table to replicate the problem.

Options: ReplyQuote


Subject
Views
Written By
Posted
Re: why must i specify an index in query?
934
July 03, 2015 03:06PM


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.