[mythtv-commits] Ticket #4609: Scheduler speedup - SQL with negative values on unsigned int columns.

[MythTV]

#4609: Scheduler speedup - SQL with negative values on unsigned int columns.
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 Reporter:  Mark Buechler <Mark.Buechler at gmail.com>  |       Owner:  ijr    
     Type:  patch                                    |      Status:  new    
 Priority:  minor                                    |   Milestone:  unknown
Component:  mythtv                                   |     Version:  head   
 Severity:  medium                                   |     Mlocked:  0      
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 I've noticed a very long running query in the scheduler "DELETE FROM
 program WHERE manualid = -1 OR  (manualid <> 0 AND -1 = -1);" which is
 invalid due to manualid being defined as an unsigned int (as well as
 recordid). This, on my system running mysql 5.0.41, takes typically 11
 seconds to run. By removing the negative value in the WHERE clause it
 takes 0 seconds.

 Attached is a patch that, instead of doing the check for "RECORDID = -1"
 in SQL, it does it in code thus eliminating the slow WHERE clause.

 There may be more of these but these are the two biggest for me. With this
 patch, my scheduler runs go from 17 seconds average down to 5-6 seconds
 average.

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Ticket URL: <http://svn.mythtv.org/trac/ticket/4609>
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