Grant issue

Hi,

I am little confused with the Grant Usage.

As a owner of schema cant i give grant Usage on my own schema to other users?

Login as S1 and my schema name is also S1:

Create a table:

-->create table S1.test2 as select * from test1;
CREATE TABLE

Grant same table to another user called sch2:

-->grant select on S1.test2 to sch2;
WARNING 5682: USAGE privilege on schema "S1" also needs to be granted to "sch2"
GRANT PRIVILEGE

As per the above message i tried to grant usage on my schema to other user sch2:

-->grant usage on schema s1 to sch2;
ROLLBACK 2061: "USAGE" privilege(s) for schema "S1" could not be granted to "sch2"
HINT: Check grantor's granting options

Then i logged in as Super user and chek the info of the schema:

vertadm=> select * from grants where object_name='S1';
-[ RECORD 1 ]----------+----------------------------------------------------------------------------
grant_id | 81064793496193290
grantor_id | 45035996273704962
grantor | admin
privileges_description | INSERT*, SELECT*, UPDATE*, DELETE*, REFERENCES*, USAGE*, CREATE*, TRUNCATE*
object_schema |
object_name | S1
object_id | 81064793496192044
object_type | SCHEMA
grantee_id | 45035996273704962
grantee | admin
-[ RECORD 2 ]----------+----------------------------------------------------------------------------
grant_id | 81064793496193292
grantor_id | 45035996273704962
grantor | admin
privileges_description | USAGE, CREATE
object_schema |
object_name | S1

object_type | SCHEMA
grantee_id | 45035996273704962
grantee | admin

Thanks in advance.