greatest/least semantics different between oracle and postgres

[Bruno Wolff III <bruno@xxxxxxxx>]

The following is just FYI.
I was recently doing some stuff with greatest() on oracle (9.2.0.8.0) and
noticed that it returned null if ANY of the arguments were null. Out of
curiosity I checked postgres' definition of that function and found that it
returns null only if ALL of the arguments are null.