Andre Ranieri (12/17/2012)
if the left side of the equal sign is a calculation, then the WHERE clause is "non sargeable", meaning that the optimizer can't use simple search arguments and must instead build an efficient query plan and must calculate every field in your table in this matter.
That just simply isn't true. The sql engine does not care at all which side of the equal sign a given predicate is located. If it were that simple to make it sargable you could switch the order of the equals predicate. I know that even the wiki article mentions the left side of the equation but consider this from the wiki example.
Non-Sargable: Select ... WHERE Year(date) = 2012
If it were try that to make it sargable the function can't be on the left side then that is like saying that the following is sargable
WHERE 2012 = Year(date)
The above is no more sargable than the first but the left side of the equation is a constant and not a function.
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