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Re: Query optimization
Posted by: Jan Kowalski
Date: May 22, 2013 08:08AM

I,ve read here http://www.mysqlperformanceblog.com/2011/10/13/when-explain-estimates-can-go-wrong/ that mysql uses “the number of rows” estimation to pick and choose indexes.
In my case explain shows 261099 rows when query uses status_modifiedgmt index without any forcement, and 260903 rows when I force type_status_date index. So why mysql stubbornly chooses status_modifiedgmt index?

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May 22, 2013 08:08AM


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