>Sent: Monday, March 14, 2011 8:52 PM
>To: Johan De Meersman
>Subject: Re: "IF"
>>>>> 2011/03/14 16:08 +0100, Johan De Meersman >>>>
>I'm afraid I'm not authoritative on this, but it seems to me that it would be
>very very bad if the third, unused expression were to be evaluated - not only
>from a performance point of view, but who is to say that that expression is
>a user-defined function that modifies the database ?
>Yes, but Access s "IIF", of the same use, evaluates all three, and the
>documentation explicitly says so. MySQL s, that I have seen, says neither.
>Assuming the worst is safer, and then one uses CASE ..., but if not, ....
[JS] Also some optimizers (and I don't know if MySQL is that clever) will
figure out which term is the cheapest to evaluate, and will change the order
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