The emergence of problems is the continuous advancement of technology. In order to better realize the promotion of value!
create view tab1 select * from B.tab1; //Execute under User A
grant CREATE SYNONYM to A; //DBAOr authorized users
create synonym tab1 for B.tab1;
grant select on B to A; //AUsers can view tables under User B without prefixes, just like queries under User B.
Note: Authorization of table access to A user by B user is required.