Optimizer Stablility

[Chris Reston]

Hi All,

I have a colleague at work who strongly opposes the use of VIEWs in MySQL. One of the reasons he gives is (quote):

"Unpredictable performance, the performance of a query might degrade by orders of magnitude if the optimizer decides on a different solution. This can happen at any time and without warning."

This seems very strange to me. As far as I know the only time the optimizer strategy can change is on database upgrade, but even then the performance should be predictable (i.e. more or less constant under the same circumstances).

Is there anything in his statement?

Chris