Re: CREATE/DROP ROLE transactional? GRANT/REVOKE?

> On 06/03/2023 14:19 CET Dominique Devienne <ddevienne(at)gmail(dot)com> wrote:
>
> Perhaps I missed it in the doc (e.g. [1]), but are DDLs around ROLEs and
> GRANTs transactional?

Have you tried? DDL is transactional unless stated otherwise (cf. CREATE DATABASE,
CREATE INDEX CONCURRENTLY, CREATE TABLESPACE).

Run the following psql script:

drop role if exists alice, bob;

\du

begin;
create role alice;
\du
rollback;

\du

begin;
create role alice;
create role bob;
commit;

\du

begin;
grant alice to bob;
\du
rollback;

\du

begin;
drop role alice;
\du
rollback;

\du

Output:

DROP ROLE
List of roles
Role name | Attributes | Member of
-----------+------------------------------------------------------------+-----------
postgres | Superuser, Create role, Create DB, Replication, Bypass RLS | {}

BEGIN
CREATE ROLE
List of roles
Role name | Attributes | Member of
-----------+------------------------------------------------------------+-----------
alice | Cannot login | {}
postgres | Superuser, Create role, Create DB, Replication, Bypass RLS | {}

ROLLBACK
List of roles
Role name | Attributes | Member of
-----------+------------------------------------------------------------+-----------
postgres | Superuser, Create role, Create DB, Replication, Bypass RLS | {}

BEGIN
CREATE ROLE
CREATE ROLE
COMMIT
List of roles
Role name | Attributes | Member of
-----------+------------------------------------------------------------+-----------
alice | Cannot login | {}
bob | Cannot login | {}
postgres | Superuser, Create role, Create DB, Replication, Bypass RLS | {}

BEGIN
GRANT ROLE
List of roles
Role name | Attributes | Member of
-----------+------------------------------------------------------------+-----------
alice | Cannot login | {}
bob | Cannot login | {alice}
postgres | Superuser, Create role, Create DB, Replication, Bypass RLS | {}

ROLLBACK
List of roles
Role name | Attributes | Member of
-----------+------------------------------------------------------------+-----------
alice | Cannot login | {}
bob | Cannot login | {}
postgres | Superuser, Create role, Create DB, Replication, Bypass RLS | {}

BEGIN
DROP ROLE
List of roles
Role name | Attributes | Member of
-----------+------------------------------------------------------------+-----------
bob | Cannot login | {}
postgres | Superuser, Create role, Create DB, Replication, Bypass RLS | {}

ROLLBACK
List of roles
Role name | Attributes | Member of
-----------+------------------------------------------------------------+-----------
alice | Cannot login | {}
bob | Cannot login | {}
postgres | Superuser, Create role, Create DB, Replication, Bypass RLS | {}

> Since I'm creating many ROLEs and making many GRANTs, based info I read from
> PostgreSQL itself (in pg_catalog and elsewhere), should everything be in a
> single transaction?

If it should be atomic and the commands are allowed in transactions, then yes,
use transactions.

--
Erik