Selecting from a view when tables are in more than one schema problem

Question

I give up where am I missing it. Why is the ORA-01031 error being generated on the view u1.bv1. In testing even if I give object access to u3 I still get the same errors:
SQL>
SQL> drop user u1 cascade;
drop user u1 cascade
ERROR at line 1:
ORA-01918: user 'U1' does not exist
SQL> drop user u2 cascade;
drop user u2 cascade
ERROR at line 1:
ORA-01918: user 'U2' does not exist
SQL> drop user u3 cascade;
drop user u3 cascade
ERROR at line 1:
ORA-01918: user 'U3' does not exist
SQL> drop role aRole;
drop role aRole
ERROR at line 1:
ORA-01919: role 'AROLE' does not exist
SQL>
SQL>
SQL> select user from dual;
USER
SYS
1 row selected.
SQL>
SQL> select * from v$version;
BANNER
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - 64bi
PL/SQL Release 10.2.0.1.0 - Production
CORE     10.2.0.1.0     Production
TNS for Solaris: Version 10.2.0.1.0 - Production
NLSRTL Version 10.2.0.1.0 - Production
5 rows selected.
SQL>
SQL> create user u1 identified by u1 default tablespace users
2 quota unlimited on users;
User created.
SQL>
SQL> create user u2 identified by u2 default tablespace users
2 quota unlimited on users;
User created.
SQL>
SQL> create role aRole;
Role created.
SQL>
SQL> create user u3 identified by u3 default tablespace users;
User created.
SQL>
SQL> grant aRole to u3;
Grant succeeded.
SQL>
SQL> alter user u3 default role all;
User altered.
SQL>
SQL> grant create session to u3;
Grant succeeded.
SQL>
SQL> create table u1.t1(c1 number);
Table created.
SQL>
SQL> create table u2.t1(c1 number);
Table created.
SQL>
SQL> grant select on u2.t1 to u1;
Grant succeeded.
SQL>
SQL> create or replace view u1.bv1 as
2 select u1.t1.c1 as c1 ,u2.t1.c1 as c2
3 from u1.t1, u2.t1 where u1.t1.c1 = u2.t1.c1;
View created.
SQL>
SQL> grant select on u1.bv1 to aRole;
Grant succeeded.
SQL>
SQL> create or replace view u1.gv1 as select * from u1.t1;
View created.
SQL>
SQL> grant select on u1.gv1 to aRole;
Grant succeeded.
SQL>
SQL> connect u3/u3
Connected.
SQL>
SQL> select * from u1.bv1;
select * from u1.bv1
ERROR at line 1:
ORA-01031: insufficient privileges
SQL>
SQL> select * from u1.gv1;
no rows selected
SQL>
SQL> spool off

Answer 1

User u1 cannot do a grant on a view to other user if the view uses tables from other schemas unless you do a "with grant option" grant.
You need to do the following to make it work:
SQL> grant select on u2.t1 to u1 with grant option;
Grant succeeded.
SQL>