Query for PostgreSQL, which return name of tables used by specific materialized view, without using iformation_schema
SELECT DISTINCT pg_class.oid::regclass FROM pg_rewrite JOIN pg_depend ON pg_depend.classid = 'pg_rewrite'::regclass AND pg_depend.objid = pg_rewrite.oid AND pg_depend.refclassid = 'pg_class'::regclass
JOIN pg_class ON pg_class.oid = pg_depend.refobjid
WHERE pg_rewrite.ev_class = 'films_ext'::regclass AND pg_depend.refobjid <> pg_rewrite.ev_class AND pg_class.relkind IN ('r','f','p','v','m')