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Re: Index Not being used.
Posted by: Rick James ()
Date: May 31, 2016 09:26PM

You have aggregates (SUM) and no GROUP BY? So, you should get one line of output. Yet, you are saying it returns millions of rows.

If it does return millions of rows, what will you do with them? That is a lot to process. Can you 'process' them in sql, and return some smaller resultset.

If ORD_DATE is in the `lines` table, why have `LEFT`? The WHERE clause will exclude them anyway. Once you remove `LEFT`, the optimizer is free to start with `lines`. But then you need these two indexes:

pos_ord_headers: INDEX(ORD_ID) -- perhaps you already have it as a PRIMARY KEY.
pos_ord_lines: INDEX(ORD_DATE)

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Subject Views Written By Posted
Index Not being used. 632 Greg Mundt 05/26/2016 02:29PM
Re: Index Not being used. 330 Peter Brawley 05/26/2016 03:53PM
Re: Index Not being used. 349 Øystein Grøvlen 05/27/2016 12:45AM
Re: Index Not being used. 315 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. 310 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. 342 Greg Mundt 06/01/2016 05:40AM
Re: Index Not being used. 284 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. 339 Greg Mundt 05/27/2016 10:14AM


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