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 evalua

[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