教你快速掌握Oracle中“HINT”的30个用法

SELECT /*+USE_CONCAT*/ * FROM BSEMPMS 
WHERE DPT_NO='TDC506' AND SEX='M';

SELECT /*+NO_EXPAND*/ * FROM BSEMPMS WHERE DPT_NO='TDC506' AND SEX='M';

例如:SELECT /*+MERGE(V) */ A.EMP_NO,A.EMP_NAM,
B.DPT_NO FROM BSEMPMS A (SELET DPT_NO
,AVG(SAL) AS AVG_SAL FROM BSEMPMS B 
GROUP BY DPT_NO) V WHERE A.DPT_NO=V.DPT_NO
AND A.SAL>V.AVG_SAL;

SELECT /*+NO_MERGE(V) */ A.EMP_NO,
A.EMP_NAM,B.DPT_NO FROM BSEMPMS A 
(SELECT DPT_NO,AVG(SAL) 
AS AVG_SAL FROM BSEMPMS B GROUP BY DPT_NO) 
V WHERE A.DPT_NO=V.DPT_NO AND A.SAL>V.AVG_SAL;

SELECT /*+ORDERED*/ A.COL1,B.COL2,C.COL3 FROM 
TABLE1 A,TABLE2 B,TABLE3 C WHERE A.COL1=B.COL1 AND B.COL1=C.COL1;

SELECT /*+ORDERED USE_NL(BSEMPMS)*/ BSDPTMS.DPT_NO,
BSEMPMS.EMP_NO,BSEMPMS.EMP_NAM FROM BSEMPMS,BSDPTMS
WHERE BSEMPMS.DPT_NO=BSDPTMS.DPT_NO;