On Mon, 2007-01-15 at 10:51 -0800, Richard Troy wrote: > I therefore propose that the engine evaluate - > benchmark, if you will - all functions as they are ingested, or > vacuum-like at some later date (when valid data for testing may exist), > and assign a cost relative to what it already knows - the built-ins, for > example.
That seems pretty unworkable. It is unsafe, for one: evaluating a function may have side effects (inside or outside the database), so the DBMS cannot just invoke user-defined functions at whim. Also, the relationship between a function's arguments and its performance will often be highly complex -- it would be very difficult, not too mention computationally infeasible, to reconstruct that relationship automatically, especially without any real knowledge about the function's behavior. -Neil ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings
