PostgreSQL 확장 플러그인 설치 여부

SELECT n.nspname, p.proname, pg_catalog.pg_get_function_arguments(p.oid) as params
  FROM pg_catalog.pg_proc p
  JOIN pg_catalog.pg_namespace n ON n.oid = p.pronamespace
 WHERE p.proname ~~* '%pgp_sym_encrypt%'
   AND pg_catalog.pg_function_is_visible(p.oid);