SQLÓÅ»¯¹ý³ÌÖг£¼ûOracle HINTµÄÓ÷¨
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1. /*+ALL_ROWS*/
±íÃ÷¶ÔÓï¾ä¿éÑ¡Ôñ»ùÓÚ¿ªÏúµÄÓÅ»¯·½·¨,²¢»ñµÃ×î¼ÑÍÌÍÂÁ¿,ʹ×ÊÔ´ÏûºÄ×îС»¯.
ÀýÈç:
SELECT /*+ALL+_ROWS*/ EMP_NO,EMP_NAM,DAT_IN from BSEMPMS WHERE EMP_NO='SCOTT';
2. /*+FIRST_ROWS*/
±íÃ÷¶ÔÓï¾ä¿éÑ¡Ôñ»ùÓÚ¿ªÏúµÄÓÅ»¯·½·¨,²¢»ñµÃ×î¼ÑÏìӦʱ¼ä,ʹ×ÊÔ´ÏûºÄ×îС»¯.
ÀýÈç:
SELECT /*+FIRST_ROWS*/ EMP_NO,EMP_NAM,DAT_IN from BSEMPMS WHERE EMP_NO='SCOTT';
3. /*+CHOOSE*/
±íÃ÷Èç¹ûÊý¾Ý×ÖµäÖÐÓзÃÎʱíµÄͳ¼ÆÐÅÏ¢,½«»ùÓÚ¿ªÏúµÄÓÅ»¯·½·¨,²¢»ñµÃ×î¼ÑµÄÍÌÍÂÁ¿;
±íÃ÷Èç¹ûÊý¾Ý×ÖµäÖÐûÓзÃÎʱíµÄͳ¼ÆÐÅÏ¢,½«»ùÓÚ¹æÔò¿ªÏúµÄÓÅ»¯·½·¨;
ÀýÈç:
SELECT /*+CHOOSE*/ EMP_NO,EMP_NAM,DAT_IN from BSEMPMS WHERE EMP_NO='SCOTT';
4. /*+RULE*/
±íÃ÷¶ÔÓï¾ä¿éÑ¡Ôñ»ùÓÚ¹æÔòµÄÓÅ»¯·½·¨.
ÀýÈç:
SELECT /*+ RULE */ EMP_NO,EMP_NAM,DAT_IN from BSEMPMS WHERE EMP_NO='SCOTT';
5. /*+FULL(TABLE)*/
±íÃ÷¶Ô±íÑ¡ÔñÈ«¾ÖɨÃèµÄ·½·¨.
ÀýÈç:
SELECT /*+FULL(A)*/ EMP_NO,EMP_NAM from BSEMPMS A WHERE EMP_NO='SCOTT';
6. /*+ROWID(TABLE)*/
ÌáʾÃ÷È·±íÃ÷¶ÔÖ¸¶¨±í¸ù¾ÝROWID½øÐзÃÎÊ.
ÀýÈç:
SELECT /*+ROWID(BSEMPMS)*/ * from BSEMPMS WHERE ROWID>='AAAAAAAAAAAAAA'
AND EMP_NO='SCOTT';
7. /*+CLUSTER(TABLE)*/
ÌáʾÃ÷È·±íÃ÷¶ÔÖ¸¶¨±íÑ¡Ôñ´ØÉ¨ÃèµÄ·ÃÎÊ·½·¨,ËüÖ»¶Ô´Ø¶ÔÏóÓÐЧ.
ÀýÈç:
SELECT /*+CLUSTER */ BSEMPMS.EMP_NO,DPT_NO from BSEMPMS,BSDPTMS
WHERE DPT_NO='TEC304' AND BSEMPMS.DPT_NO=BSDPTMS.DPT_NO;
8. /*+INDEX(TABLE INDEX_NAME)*/
±íÃ÷¶Ô±íÑ¡ÔñË÷ÒýµÄɨÃè·½·¨.
ÀýÈç:
SELECT /*+INDEX(BSEMPMS SEX_INDEX) USE SEX_INDEX BECAUSE THERE ARE FEWMALE BSEMPMS */ from BSEMPMS WHERE SEX='M';
9. /*+INDEX_ASC(TABLE INDEX_NAME)*/
±íÃ÷¶Ô±íÑ¡ÔñË÷ÒýÉýÐòµÄɨÃè·½·¨.
ÀýÈç:
SELECT /*+INDEX_ASC(BSEMPMS PK_BSEMPMS) */ from BSEMPMS WHERE DPT_NO='SCOTT';
10. /*+INDEX_COMBINE*/
Ϊָ¶¨±íÑ¡Ôñλͼ·ÃÎÊ·¾,Èç¹ûINDEX_COMBINEÖÐûÓÐÌṩ×÷Ϊ²ÎÊýµÄË÷Òý,½«Ñ¡Ôñ³öλͼË÷ÒýµÄ²¼¶û×éºÏ·½Ê½.
ÀýÈç:
SELECT /*+INDEX_COMBINE(BSEMPMS SAL_BMI HIREDATE_BMI)*/ * from BSEMPMS
WHERE SAL <5000000 AND HIREDATE <SYSDATE;
11. /*+INDEX_JOIN(TA
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