[HACKERS] Should planner fold stable functions for estimation purposes?

2004-03-12 Thread Tom Lane
I've been toying with the notion of allowing the planner to compute the current values of stable functions when it's trying to estimate selectivities. For instance, in a query like select ... where timestampcol = now() - interval '1 day'; we currently throw up our hands and treat the

Re: [HACKERS] Should planner fold stable functions for estimation purposes?

2004-03-12 Thread Tom Lane
Rod Taylor [EMAIL PROTECTED] writes: It would not be correct to reduce the righthand side to a constant in advance of execution, of course, but is it reasonable to compute its current value solely for purposes of comparison to column statistics? So this means it would be double evaluated? A