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Re: timestamp, datetime as default value as current_timestamp [PARTITION]
Posted by: Rick James
Date: August 31, 2012 09:52AM

> 3. the optimizer will use a fraction of the partitions (10 first up to now, that may be fixed in a later release) to estimate the index cardinalities.

See
http://dev.mysql.com/doc/refman/5.0/en/innodb-parameters.html#sysvar_innodb_use_legacy_cardinality_algorithm (5.0.82 / 5.1.35)
and
http://dev.mysql.com/doc/refman/5.1/en/innodb-parameters.html#sysvar_innodb_stats_sample_pages ( 5.1.38, not in 5.0 )
and
"persistent statistics" (5.6.2):
http://blogs.innodb.com/wp/2011/04/innodb-persistent-statistics-at-last/

All of those are kludges. If you use any of them to fix one problem, you are potentially making another problem worse.

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Re: timestamp, datetime as default value as current_timestamp [PARTITION]
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