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Re: mySQL performance problem on subqueries
Posted by: KimSeong Loh
Date: May 15, 2006 06:17PM

Do you aware that if the query returns 2377 rows, then the subselect is executed 2377 times, not 1 time.

Counting a lot of rows is very fast and constant time in MyISAM but only if there is no Where condition and no Group by, means all rows in the table, this is beacuse the number of rows is stored in the table, so no actual counting is required.

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Re: mySQL performance problem on subqueries
May 15, 2006 06:17PM

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