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Re: JOIN query too slow
Posted by: Rick James
Date: October 16, 2012 07:48PM

There is virtually no reason for the JOINs. All the info is fetched from the first table. The other tables seem to verify that each of the 4980 rows has a friend 4 levels removed.

The estimated number of rows to fetch is
4980 * 1 * 5 * 5 * 5 = 600K
So, it takes a lot of work.

Check to see if key_buffer_size is set properly:
http://mysql.rjweb.org/doc.php/memory

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