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Re: Slow query log 'Rows_examined' vs 'explain select' rows
Posted by: Rick James
Date: January 10, 2013 08:56PM

Please provide SHOW CREATE TABLE so we don't have to guess.

Do you have an index _starting_ with vss_datelastvisited ?

Sometimes InnoDB gets the "statistics" wrong, and does a table scan when it clearly should not. 5.6 has some features that _may_ provide relief from that.

The EXPLAIN will use the current statistics, and may not reflect the actual query plan used.

Something like this:
PARTITION BY RANGE (TO_DAYS(vss_datelastvisited))
would make it run faster, even when it goes berserk.

Tips on PARTITIONing -- see start of http://mysql.rjweb.org/doc.php/partitionmaint

Did you notice that your timespan is 1 second shy of a whole number of hours?

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Re: Slow query log 'Rows_examined' vs 'explain select' rows
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January 10, 2013 08:56PM


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