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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 DP
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