List:General Discussion« Previous MessageNext Message »
From:hsv Date:February 5 2013 8:10pm
Subject:RE: IF and CASE
View as plain text  
>>>> 2013/02/05 17:06 +0000, Rick James >>>>
As a Rule of Thumb, function evaluation time is not significant to the overall time for
running a query.  (I see IF and CASE as 'functions' for this discussion.)

Do you have evidence that says that IF is slower?  Perhaps using BENCHMARK()? 
Not BENCHMARK: I did a query with one, and also with the other, and repeated each at least
a dozen times, and looked at the reported time. The IF-variant took ever so slightly more
time than the CASE-variant.

But which of the arguments are always evaluated, which only at need? This could be a
difference, that IF s arguments always are, CASE s only at need.

IF and CASEhsv5 Feb
  • RE: IF and CASERick James5 Feb
    • RE: IF and CASEhsv5 Feb