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Re: Index Not being used.
Posted by: Øystein Grøvlen ()
Date: May 27, 2016 12:45AM

Hi,

The optimizer may have determined that the records from 2015 is so large part of the table that it is more efficient to scan the table than to use an index.

You can try forcing the use of the index to see if that gives better performance:

... FROM pos_ord_headers FORCE INDEX(ORD_Date) ...

By the way, does not your query need a GROUP BY clause to be meaningful?

Øystein Grøvlen,
Senior Principal Software Engineer,
MySQL Group, Oracle,
Trondheim, Norway

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Subject Views Written By Posted
Index Not being used. 625 Greg Mundt 05/26/2016 02:29PM
Re: Index Not being used. 329 Peter Brawley 05/26/2016 03:53PM
Re: Index Not being used. 345 Øystein Grøvlen 05/27/2016 12:45AM
Re: Index Not being used. 314 Greg Mundt 05/27/2016 07:05AM
Re: Index Not being used. 311 Rick James 05/27/2016 11:29PM
Re: Index Not being used. 309 Greg Mundt 05/31/2016 07:04AM
Re: Index Not being used. 305 Rick James 05/31/2016 09:26PM
Re: Index Not being used. 341 Greg Mundt 06/01/2016 05:40AM
Re: Index Not being used. 283 Rick James 06/01/2016 11:29AM
Re: Index Not being used. 331 Greg Mundt 06/01/2016 11:41AM
Re: Index Not being used. 333 Rick James 06/04/2016 05:14PM
Re: Index Not being used. 336 Greg Mundt 05/27/2016 10:14AM


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