Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> It occurs to me that one way to make GEQO less scary would be to
> take out the nondeterminism by resetting its random number generator
> for each query. You might get a good plan or an awful one, but at
> least it'd be the same one each time. DBAs like predictability.
+1 The biggest reason that I've tended to avoid geqo is that I would
never know when it might do something really stupid with a query one
time out of some large number, leading to mysterious complaints which
could eat a lot of time.
For a moment it seemed logical to suggest a session GUC for the seed,
so if you got a bad plan you could keep rolling the dice until you got
one you liked; but my right-brain kept sending shivers down my spine
to suggest just how uncomfortable it was with that idea....
-Kevin