Re: Updating pg_attribute - Permission denied

"Trewern, Ben" <Ben(dot)Trewern(at)mowlem(dot)com> writes:
> I was trying to update attnotnull = 't' in the pg_attribute to add Not Null
> constraint to a table. It gave me a Permission denied.
> Is this standard? Am I not allowed to change system catalogues (I am using
> the postgres superuser!)

I don't believe it --- are you *sure* you were superuser? Or perhaps
you'd turned off pg_shadow's usecatupd for yourself?

I get this behavior:

play=> update pg_attribute set attnotnull = 't' where attrelid = 334893 and
play-> attname = 'f1';
ERROR: pg_attribute: Permission denied.
play=> \c - postgres
You are now connected as new user postgres.
play=# update pg_attribute set attnotnull = 't' where attrelid = 334893 and
play-# attname = 'f1';
UPDATE 1
play=#

> Or can you only change attnotnull to false i.e. remove a not null
> constraint? I suppose this would make some kind of sense, as there
> could already be Nulls in the field.

It's up to you to worry about that sort of consistency issue if you
reach in and hack pg_attribute directly. Certainly the permission
check is not concerned with it.

regards, tom lane