How to change owner of PostgreSQL database/schema/table/sequence/views/functions/types?

pg_change_owner.sql

DO $$
DECLARE
	sch RECORD;
	tab RECORD;
	seq RECORD;
	viw RECORD;
	mat RECORD;
	fun RECORD;
	ctype RECORD;
	v_schema_exclude text[] := '{pg_catalog,information_schema,monitor,repack}';
	v_newowner varchar := 'migrations';
BEGIN
	RAISE INFO 'The new owner of tables, sequences, views, mat views, functions, schemas and the database will be [%]', v_newowner;
	FOR sch IN
		SELECT schemaname
		FROM pg_tables WHERE NOT (schemaname = ANY(v_schema_exclude))
		GROUP BY schemaname
	LOOP
		RAISE INFO 'Use schema %', sch.schemaname;
		FOR tab IN
			SELECT tablename
			FROM pg_tables
			WHERE schemaname = sch.schemaname
			ORDER BY 1
		LOOP
			RAISE INFO 'ALTER TABLE %.% OWNER TO %;', sch.schemaname, tab.tablename, v_newowner;
			EXECUTE format('ALTER TABLE %I.%I OWNER TO %I;', sch.schemaname, tab.tablename, v_newowner);
		END LOOP;
		FOR seq IN
			SELECT sequence_name 
			FROM information_schema.sequences
			WHERE sequence_schema = sch.schemaname
			ORDER BY 1
		LOOP
			RAISE INFO 'ALTER SEQUENCE %.% OWNER TO %;', sch.schemaname, seq.sequence_name, v_newowner;
			EXECUTE format('ALTER SEQUENCE %I.%I OWNER TO %I;', sch.schemaname, seq.sequence_name, v_newowner);
		END LOOP;
		FOR viw IN
			SELECT table_name 
			FROM information_schema.views
			WHERE table_schema = sch.schemaname
				AND table_name NOT LIKE 'pg_stat_%'
			ORDER BY 1
		LOOP
			RAISE INFO 'ALTER VIEW %.% OWNER TO %;', sch.schemaname, viw.table_name, v_newowner;
			EXECUTE format('ALTER VIEW %I.%I OWNER TO %I;', sch.schemaname, viw.table_name, v_newowner);
		END LOOP;
		FOR mat IN
			SELECT matviewname
			FROM pg_matviews
			WHERE schemaname = sch.schemaname
			ORDER BY 1
		LOOP
			RAISE INFO 'ALTER TABLE %.% OWNER TO %;', sch.schemaname, mat.matviewname, v_newowner;
			EXECUTE format('ALTER TABLE %I.%I OWNER TO %I;', sch.schemaname, mat.matviewname, v_newowner);
		END LOOP;
		FOR fun IN
			SELECT p.proname AS fname, pg_get_function_identity_arguments(p.oid) AS fargs
			FROM pg_proc p JOIN pg_namespace nsp ON p.pronamespace = nsp.oid JOIN pg_roles r ON p.proowner = r.oid
			WHERE nsp.nspname = sch.schemaname AND r.rolname NOT IN ('postgres')
			ORDER BY 1
		LOOP
			RAISE INFO 'ALTER FUNCTION %.%(%) OWNER TO %;', sch.schemaname, fun.fname, fun.fargs, v_newowner;
			EXECUTE format('ALTER FUNCTION %I.%I(%I) OWNER TO %I;', sch.schemaname, fun.fname, fun.fargs, v_newowner);
		END LOOP;
		FOR ctype IN
			SELECT t.typname as type
			FROM pg_type t 
			LEFT JOIN pg_catalog.pg_namespace n ON n.oid = t.typnamespace 
			WHERE (t.typrelid = 0 OR (SELECT c.relkind = 'c' FROM pg_catalog.pg_class c WHERE c.oid = t.typrelid)) 
			AND NOT EXISTS(SELECT 1 FROM pg_catalog.pg_type el WHERE el.oid = t.typelem AND el.typarray = t.oid)
			AND n.nspname = sch.schemaname
		LOOP
			RAISE INFO 'ALTER TYPE %.% OWNER TO %;', sch.schemaname, ctype.type, v_newowner;
			EXECUTE format('ALTER TYPE %I.%I OWNER TO %I;', sch.schemaname, ctype.type, v_newowner);
		END LOOP;
		RAISE INFO 'ALTER SCHEMA % OWNER TO %;', quote_ident(sch.schemaname), v_newowner;
		EXECUTE format('ALTER SCHEMA %I OWNER TO %I;', quote_ident(sch.schemaname), v_newowner);
	END LOOP;
	RAISE INFO 'ALTER DATABASE % OWNER TO %;', quote_ident(current_database()), v_newowner;
	EXECUTE format('ALTER DATABASE %I OWNER TO %I;', quote_ident(current_database()), v_newowner);
END;
$$;

This script can be used if you have limited access rights to the instance (for example, you use Managed Service for PostgreSQL at a Cloud provider).
If you have full rights and access is available under the postgres user - use the standard SQL command - REASSIGN OWNED