Re: Support NOT VALID / VALIDATE constraint options for named NOT NULL constraints

hi.

attached patch is for address pg_dump inconsistency
when parent is "not null not valid" while child is "not null".


The following query before/after pg_dump should return the same result.
select conrelid::regclass::text, conname, convalidated, coninhcount,
conislocal, conparentid, contype
from pg_constraint
where conrelid::regclass::text = ANY('{inhnn, inhnn_cc, inhnn_cc_1}')
order by 1,2;

--test cases:
CREATE TABLE inhnn (a INTEGER);
ALTER TABLE inhnn ADD CONSTRAINT cc not null a NOT VALID;
CREATE TABLE inhnn_cc(a INTEGER) INHERITS(inhnn);
CREATE TABLE inhnn_cc_1(a INTEGER) INHERITS(inhnn_cc, inhnn);

master pg_dump output is:

CREATE TABLE public.inhnn (a integer);
CREATE TABLE public.inhnn_cc (a integer) INHERITS (public.inhnn);
CREATE TABLE public.inhnn_cc_1 (a integer) INHERITS (public.inhnn_cc,
public.inhnn);
ALTER TABLE public.inhnn ADD CONSTRAINT cc NOT NULL a NOT VALID;


with the attached patch, pg_dump output is:
CREATE TABLE public.inhnn (a integer);

CREATE TABLE public.inhnn_cc (a integer CONSTRAINT cc NOT NULL)
INHERITS (public.inhnn);
CREATE TABLE public.inhnn_cc_1 (a integer CONSTRAINT cc NOT NULL)
INHERITS (public.inhnn_cc, public.inhnn);

ALTER TABLE public.inhnn ADD CONSTRAINT cc NOT NULL a NOT VALID;
-------------

As you can see, in master, pg_dump will make {inhnn, inhnn_cc, inhnn_cc_1}
not-null constraint's pg_constraint.convalidated set as false.
but we should only make inhnn's not-null constraint convalidated as false.