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We're trying to manage and tune our MySql.

One alert we're getting in phpMyAdmin is this:

Select full joinDocumentation   421     The number of joins that do not use indexes. If this value is not 0, you should carefully check the indexes of your tables. 

Apparently, there are joins that are not using indexes. These have run 421 times since rebooting mysql (last reboot was only hours ago). I've hunted through our code, and run EXPLAIN on dozens and dozens queries trying to identify the culprit, but to no success.

Is there a way I can identify the queries that are triggering this alert so I can attempt to change or improve them?

Thanks in advance.

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1 Answer 1

up vote 3 down vote accepted

In your my.cnf, enable the slow queries log, and add the option log-queries-not-using-indexes could give you some clues about the culprits.

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Thank you. I'll give this a try. – Kevin Mar 21 '13 at 0:13

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