Re: BUG #15247: At 'ALTER TABLE ADD COLUMN fast default' , Set attmissingval to NULL in the pg_attribute, query fail

Andrew Gierth <andrew@tao11.riddles.org.uk> writes:
> "PG" == PG Bug reporting form <noreply@postgresql.org> writes:
>  PG> (4)  update pg_attribute set attmissingval = NULL where attname = 'b';

> Nobody ever claimed that you could update pg_attribute without crashing
> the server; I can think of half a dozen ways to do it.

Specifically, you broke it by not keeping atthasmissing consistent with
attmissingval.  Manually corrupting catalogs like that is not a supported
operation.

            regards, tom lane