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From:misiaq Date:May 12 2011 1:15pm
Subject:Re: Efficiency of NULLIFie expression
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hsv@stripped wrote:
(...)
> 
> Is the optimizer so clever as to set that test outside the expression, and only then
> evaluate it when "houmuch" and "SharePrice" are not equal?
> 
> 

Try it yourself:
mysql > explain extended select * from table1;

and then
mysql > show warnings;

You will see the optimized query.

http://dev.mysql.com/doc/refman/5.0/en/explain.html

Regards,
m
Thread
Efficiency of NULLIFie expressionhsv12 May
Re: Efficiency of NULLIFie expressionmisiaq12 May
  • Re: Efficiency of NULLIFie expressionhsv14 May
Re: Efficiency of NULLIFie expressionmisiaq14 May
  • Re: Efficiency of NULLIFie expressionhsv15 May
Re: Efficiency of NULLIFie expressionhsv17 May