Making postgres tables be default-owned by one "master" user, regardless of who created them.

nightmare.sql

Run as `postgres`:
------------------

BEGIN;

DO
$body$
BEGIN
    IF NOT EXISTS (SELECT 1 FROM pg_user WHERE usename = 'table_owner') THEN
        CREATE GROUP table_owner;
    END IF;
END
$body$;

CREATE OR REPLACE FUNCTION change_owner() RETURNS event_trigger AS $$
BEGIN
    IF NOT EXISTS (SELECT 1 FROM pg_user WHERE usename = current_user and usesuper = true) THEN
        REASSIGN OWNED BY current_user TO table_owner;
    END IF;
END;
$$ LANGUAGE plpgsql;

DROP EVENT TRIGGER IF EXISTS change_owner;
CREATE EVENT TRIGGER change_owner ON ddl_command_end EXECUTE PROCEDURE change_owner();

COMMIT;

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Then on each user who will be creating/modifying tables etc:

grant table_owner to USERNAME;