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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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Slow query log 'Rows_examined' vs 'explain select' rows
9914
Ramon Rockx
January 09, 2013 05:26AM
Re: Slow query log 'Rows_examined' vs 'explain select' rows
3660
Rick James
January 10, 2013 08:56PM
Re: Slow query log 'Rows_examined' vs 'explain select' rows
3377
Ramon Rockx
January 15, 2013 09:18AM
Re: Slow query log 'Rows_examined' vs 'explain select' rows
2596
Rick James
January 16, 2013 09:16AM


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