sql 전문가 각이드 2과목 2장 6절 윈도우 함수중에
SQL> SELECT MGR, ENAME, HIREDATE, SAL, MIN(SAL) OVER(PARTITION BY MGR ORDER BY HIREDATE) as MGR_MIN FROM EMP; MGR ENAME HIREDATE SAL MGR_MIN ---------- ---------- --------- ---------- ---------- 7566 FORD 03-DEC-81 3000 3000 7566 SCOTT 09-DEC-82 3000 3000 7698 ALLEN 20-FEB-81 1600 1600 7698 WARD 22-FEB-81 1250 1250 7698 TURNER 08-SEP-81 1500 1250 7698 MARTIN 28-SEP-81 1250 1250 7698 JAMES 03-DEC-81 950 950 7782 MILLER 23-JAN-82 1300 1300 7788 ADAMS 12-JAN-83 1100 1100 7839 JONES 02-APR-81 2975 2975 7839 BLAKE 01-MAY-81 2850 2850 7839 CLARK 09-JUN-81 2450 2450 7902 SMITH 17-DEC-80 800 800 KING 17-NOV-81 5000 5000
위 부분에서 제가 예상한 결과는
MGR ENAME HIREDATE SAL MGR_MIN ---------- ---------- --------- ---------- ---------- 7566 FORD 03-DEC-81 3000 3000 7566 SCOTT 09-DEC-82 3000 3000 7698 ALLEN 20-FEB-81 1600 950 7698 WARD 22-FEB-81 1250 950 7698 TURNER 08-SEP-81 1500 950 7698 MARTIN 28-SEP-81 1250 950 7698 JAMES 03-DEC-81 950 950 7782 MILLER 23-JAN-82 1300 1300 7788 ADAMS 12-JAN-83 1100 1100 7839 JONES 02-APR-81 2975 2450 7839 BLAKE 01-MAY-81 2850 2450 7839 CLARK 09-JUN-81 2450 2450 7902 SMITH 17-DEC-80 800 800 KING 17-NOV-81 5000 5000
이렇게 예상을 했는데 예상과 다른 결과가 나오더군요. 그 이유를 좀 알고싶습니다.