Left Outer Join - Full Table Scan on Both Table

Dear Experts,

We have an SQL seleting Two Table records using Left Outer Join doing Full Table scan on both Table. How do we avoid the Full Table Scan.

      select A.EMPNO,A.ENAME from EMP A

              LEFT OUTER JOIN EMP1 B 

     ON A.EMPNO= B.EMPNO

    We do have primary key on both Tables compination of EMPNO

    Your expertise help is required to change the logic without doing full table scan.

Regards

Mudhalvan M.M