And, this is just adding new syntactic support for SQL standards compliance, right? I don't think it's really a new control-flow if you ignore syntactic differ

And, this is just adding new syntactic support for SQL standards compliance, right? I don't think it's really a new control-flow if you ignore syntactic differences. I think you can get the equivalent behavior out of BEGIN/EXCEPT blocks in plpgsql functions. I think this behaves as if you used SAVEPOINT and ROLLBACK TO SAVEPOINT which have been directly supported in postgresql but not in functions.