Stephen Frost <sfrost@snowman.net> writes:
> Honestly, I really disliked the code which assumed pg_attribute had no
> NULLable/toastable columns and used what seemed like pretty gruesome
> hacks to create pg_attribute structures.
Agreed, but that seems orthogonal to the point here, which is that a
column's default expression is a distinct object for dependency purposes
and so it needs its own ID. An OID in the pg_attrdef catalog works
nicely for that; the alternatives I've thought of seem like kluges.
> If we were to accept the pg_attrdef approach, why aren't we
> doing a pg_attracl table instead of adding a column to pg_attribute?
That's actually not an unreasonable question. If you were to do that
then you could attach OIDs to the attribute ACLs, which might be a nicer
representation in pg_shdepend than you were thinking of using.
regards, tom lane
