Problem with function aclcontains, features or bug?

Hi All,

I have some problem with get permission for table/view before make real
SELECT/UPDATE/INSERT/DELETE operations.

spidermon=# \d objects_view
          View "objects_view"
...

spidermon=# \z objects_view
   Access permissions for database "spidermon"
   Relation   |        Access permissions        
--------------+----------------------------------
 objects_view | {"=","pvi=r","group netadmin=r"}
(1 row)

spidermon=# SELECT aclcontains ( ( SELECT relacl FROM pg_class where
relname = 'objects_view' ), 'user pvi=r' );
 aclcontains 
-------------
 t
(1 row)

It's result OK.
But, next result is wrong.

spidermon=# SELECT aclcontains ( ( SELECT relacl FROM pg_class where
relname = 'objects_view' ), 'user pvi=w' );
 aclcontains 
-------------
 t
(1 row)

Same problem with permission for group.

How I can know permission for user/group before make real operations?

FreeBSD 4.2,  postgresql 7.0.3.

Thanks

-- 

 Vadim I. Passynkov, Axxent Corp.
 mailto:pvi@axxent.ca