>>>>> "Aleksandr" == Aleksandr Parfenov <a.parfe...@postgrespro.ru> writes:
>> From an implementation point of view your patch is obviously broken >> in many ways (starting with not checking varattno anywhere, and not >> actually checking anywhere if the expression is volatile). Aleksandr> The actual checking if the expression volatile or not is Aleksandr> done inside evaluate_function(). This is called through few Aleksandr> more function in eval_const_experssion(). If it's volatile, Aleksandr> the eval_const_expression() will return FuncExpr node, Const Aleksandr> otherwise. It also checks are arguments immutable or not. You're missing a ton of other possible cases, of which by far the most notable is function inlining: eval_const_expressions will inline even a volatile function and return a new expression tree (which could be almost anything depending on the function body). Aleksandr> I agree about varattno, it should be checked. Even in case Aleksandr> of SRF not replaced, it is better to be sure that Var points Aleksandr> to first (and the only) attribute. It's not a matter of "better", but of basic correctness. Functions can return composite values with columns. -- Andrew (irc:RhodiumToad)
