daniel alvarez <d-alvarez(at)gmx(dot)de> writes:
> Why should user-defined tables have OIDs by default?
At this point it's just for historical reasons. There actually is a
proposal on the table to flip the default to WITHOUT OIDS, but so far
it's not been accepted because of worries about compatibility. See
the pghackers archives a few weeks back.
regards, tom lane