After assigning permissions and restricting access, it can happen that users will be dropped from the system. Unsurprisingly, the commands to do that are the DROP ROLE and DROP USER commands:
test=# \h DROP ROLE Command: DROP ROLE Description: remove a database role Syntax: DROP ROLE [ IF EXISTS ] name [, ...]
Let's give it a try. The following listing shows how this works:
test=# DROP ROLE joe;
ERROR: role "joe" cannot be dropped because some objects depend on it DETAIL: target of policy joe_pol_3 on table t_person target of policy joe_pol_2 on table t_person target of policy joe_pol_1 on table t_person privileges for table t_person owner of table t_user owner of sequence t_user_id_seq owner of default privileges on new relations belonging to role joe in schema public owner of table t_useful
PostgreSQL...