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Re: Avoiding "Using temporary; Using filesort"
Posted by: Irfan Ali
Date: July 17, 2011 04:01AM

As long as i know,

"MySQL not uses more than one index per table"

For this particular id index already used from publications table and MySQL can't utilize date key from same table.

It uses primary key id column from publications to join with publication_credits on publication_id column. And author_id from publication_credits table.

The best way to use same key for GROUP BY & ORDER BY clauses which used for filtering records in WHERE clause.

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Re: Avoiding "Using temporary; Using filesort"
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July 17, 2011 04:01AM


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