Re: Efficiency of NULLIFie expression

[misiaq]

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