As far as I can tell from a quick search through postgresql documentation, the OLD.* pseudorelation is not available for INSERT triggers and rules. And a little googleing I did, haven't pointed me to anything relevant to the following. My apology if I miss in my search such discussion happening earlier (I apreciate a pointer, where I can see pros and cons that've been raisen back then);
If not, I think having OLD.* in INSERT rules/triggers is worth pondering.
The thing is, that it would be a valuable tool to mimic table-propper functionality by a view. The OLD.* preudorelation on INSERT could provide column defaults from the underlaying table definition.
like: CREATE TABLE test (tm timestamp default now(), info text); CREATE TABLE test_view AS SELECT * FROM test; CREATE RULE with_defaults AS ON INSERT to test_view DO INSTEAD INSERT INTO test (tm,info) VALUES ( COALESCE(NEW.tm, OLD.tm), NEW.text);
so: INSERT INTO test_view (info) VALUES ('hello'); and: INSERT INTO test_view (tm, info) VALUES (null, 'hello');
both work just as if test_view was a TABLE with a default tm value defined.