SQL> WITH seven_of_nine
  2          AS (SELECT d.deptno,
  3                     d.dname,
  4                     e.ename,
  5                     e.job,
  6                     e.sal,
  7                     ROW_NUMBER () OVER (PARTITION BY d.deptno ORDER BY e.sal)
  8                        rn
  9                FROM dept d, emp e
 10               WHERE e.deptno = d.deptno)
 11    SELECT s.deptno,
 12           s.dname,
 13           s.ename,
 14           s.job,
 15           s.sal
 16      FROM seven_of_nine s
 17     WHERE s.rn <= 3
 18  ORDER BY s.deptno, s.rn;

    DEPTNO DNAME          ENAME      JOB              SAL
---------- -------------- ---------- --------- ----------
        10 ACCOUNTING     MILLER     CLERK           2100
        10 ACCOUNTING     CLARK      MANAGER         3250
        10 ACCOUNTING     KING       PRESIDENT       5800
        20 RESEARCH       SMITH      CLERK           1600
        20 RESEARCH       ADAMS      CLERK           1900
        20 RESEARCH       JONES      MANAGER         3775
        30 SALES          JAMES      CLERK           1750
        30 SALES          WARD       SALESMAN        2050
        30 SALES          MARTIN     SALESMAN        2050

9 rows selected.

SQL>