--- You can connect to another user without knowing the password, with grant connect through privilege
--- Suppose a user TEST1 wants to connect to TEST2 user and create a table and we don’t know the password of TEST2.
Conn / as sysdba
SQL >alter user TEST2 grant connect through TEST1;
User altered.
SQL >conn TEST1[TEST2]
Enter password:< Give password for TEST1>
SQL >show user
USER is "TEST2"
SQL >create table emp_test as select * from emp;
Table created.
SQL > conn / as sysdba
connected
SQL > select owner from dba_tables where table_name='EMP_TEST';
OWNER
------
TEST2