DeleteDBUser
From GombeMIWiki
Deleting a Database User
There is no web page for deleting a database user. Deletion must be done with SQL statements by a user with administrative privileges.
Listing All Users
The following query lists all users and groups:
select rolname as "user/group" , rolsuper as administrator from pg_roles order by rolname;
Deleting a User
Before deleting a user the user's schemas must be deleted. Since administrative users do not usually have their own private schemas, schema deletion need only be done for regular users.
First connect to the gombemi_test database, as an administrative user.
drop schema SOMEUSER cascade;
Then connect to the gombemi database, as an administrative user.
drop schema SOMEUSER cascade; drop role SOMEUSER;