Dmitry Dolgov <9erthalion6@gmail.com> writes:
> Just to clarify for myself, for evaluating any stable function here would it be
> enough to handle all function-like expressions (FuncExpr / OpExpr /
> DistinctExpr / NullIfExpr) and check a corresponding function for provolatile,
> like in the attached patch?
I think the entire approach is wrong here. Rather than concerning
yourself with Params, or any other specific expression type, you
should be using !contain_volatile_functions() to decide whether
an expression is run-time-constant. If it is, use the regular
expression evaluation machinery to extract the value.
regards, tom lane
