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POmysql query taking too long to execute
 

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  1. POmysql query taking too long to execute
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    <p>I have a query that is taking way too long to execute (4 seconds) even though all the fields i am querying against are indexed. Below are the query and the explain results. Any ideas what the problem is? (mysql CPU usage shoots up to 100% when executing the query</p> <pre><code>EXPLAIN SELECT count(hd.did) as NumPo, `hd`.`sid`, `src`.`Name` FROM (`hd`) JOIN `result` ON `result`.`did` = `hd`.`did` JOIN `sf` ON `sf`.`fid` = `hd`.`fid` JOIN `src` ON `src`.`sid` = `hd`.`sid` WHERE `sf`.`tid` = 2 AND `result`.`set` = 'xxxxxxx' GROUP BY `hd`.`sid` ORDER BY `NumPo` DESC LIMIT 10; +----+-------------+--------------+--------+-------------------------+---------+---------+--------------------------+------+----------------------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+--------------+--------+-------------------------+---------+---------+--------------------------+------+----------------------------------------------+ | 1 | SIMPLE | sf | ref | PRIMARY,type | type | 2 | const | 4 | Using index; Using temporary; Using filesort | | 1 | SIMPLE | hd | ref | PRIMARY,sid,fid | FeedID | 4 | f2.sf.fid | 3 | | | 1 | SIMPLE | result | ALL | resultset | NULL | NULL | NULL | 5322 | Using where; Using join buffer | | 1 | SIMPLE | src | eq_ref | PRIMARY | PRIMARY | 4 | f2.hd.sid | 1 | | +----+-------------+--------------+--------+-------------------------+---------+---------+--------------------------+------+----------------------------------------------+ </code></pre>
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    1. This table or related slice is empty.
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    1. USapplechief
    1. USapplechief
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
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    1. COWhat kind of join does just `JOIN` do?
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      1. USBrendan Long
    2. CO@BrendanLong INNER JOIN
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      1. USapplechief
 

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