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Re: Long execution time despite LIMIT 3
Posted by: Rick James ()
Date: June 23, 2011 08:53AM

That's because InnoDB (not MyISAM) silently appends the PRIMARY KEY fields to every secondary key. So, effectively, those indexes are identical. (Sorry, I should have included id so that this puzzle would not arise.)

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Subject Views Written By Posted
Long execution time despite LIMIT 3 1156 Joachim Berger 06/19/2011 12:47PM
Re: Long execution time despite LIMIT 3 489 Joachim Berger 06/19/2011 12:54PM
Re: Long execution time despite LIMIT 3 468 Rick James 06/20/2011 06:33PM
Re: Long execution time despite LIMIT 3 455 Joachim Berger 06/20/2011 11:44PM
Re: Long execution time despite LIMIT 3 478 Joachim Berger 06/21/2011 02:06AM
Re: Long execution time despite LIMIT 3 481 Rick James 06/21/2011 07:23AM
Re: Long execution time despite LIMIT 3 419 Joachim Berger 06/21/2011 07:28AM
Re: Long execution time despite LIMIT 3 501 Joachim Berger 06/21/2011 10:33AM
Re: Long execution time despite LIMIT 3 556 Rick James 06/21/2011 10:08PM
Re: Long execution time despite LIMIT 3 654 Joachim Berger 06/22/2011 12:33AM
Re: Long execution time despite LIMIT 3 509 Rick James 06/22/2011 07:26PM
Re: Long execution time despite LIMIT 3 458 Joachim Berger 06/22/2011 11:45PM
Re: Long execution time despite LIMIT 3 417 Rick James 06/23/2011 08:53AM
Re: Long execution time despite LIMIT 3 530 Joachim Berger 06/24/2011 02:51AM


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