Willy De la Court <Willy(dot)DelaCourt(at)pandora(dot)be> writes:
> I want to change the default behaviour of the data_in function without
> recompiling postgres. the functionality is the following.
> create table test (d date);
> insert into test values ('');
> this should result in the field d containing NULL and the insert
> command should work without returning an error.
Not possible at present, since a datatype's typinput function can't
return a NULL. I suppose it will be possible after we redo the
function manager interface, but in any case you'd have no hope of
changing the behavior "without recompiling postgres".
regards, tom lane