On Monday, March 17, 2014, Atri Sharma <
atri.jiit@gmail.com> wrote:
I'm not opposed to planner hints (or plan mandates), but also not optimistic they will ever get implemented, much less accepted. But if they were, I don't see a use for such fudge factors. By mandating a plan, I am already asserting I know more than the optimizer does. Maybe I am right, maybe I am wrong, but either way I have taken it out of the optimizer's hands and would not welcome it snatching control back.
If it is too deranged for me to trust, why would it not become somewhat more deranged and so decide to ignore my hints? The only setting for such a factor I would ever see myself using was the minimum, or the maximum.
The feature I would like in such hints, if they are to exist, is to set a version to which they apply. Often a fix is made very quickly after the problem is pointed out, but it could take well over a year for the fix to see production if it is not backpatched and it lands at the wrong part of the release cycle.
Cheers,
Jeff