Dominique Devienne <ddevienne@xxxxxxxxx> writes: > But still, arg names are not part of the signature. > So they should be checked after the fact. No, that's not how it works. David's comment about signature reflects the fact that the primary key of pg_proc is name + schema + input argument types. Arg names are independent of that and actually have to be checked before we consider argument type matching, because they help determine which input argument is which. (There was considerable debate when we added output arguments and argument names about whether pg_proc's primary key should be extended. We ended up not, but it was a judgment call.) regards, tom lane
