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callkris_cit
New User
Joined: 22 Apr 2006 Posts: 44
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Query1 and Query2 which one is efficient.
( Note: LAT_TP is present in Index )
Query1:
Code: |
SELECT A.ROLLNO,COUNT(*),
SUM(A.MARK)
FROM GKK.MARK_DTL A
WHERE LAT_TP <= ( SELECT MAX(LAT_ENT_TP)
FROM GKK.LOAD_DTL )
AND LAT_TP >= ( SELECT MAX(LAT_BEG_TP)
FROM GKK.LOAD_DTL )
GROUP BY A.ROLLNO; |
Query2:
Code: |
SELECT A.ROLLNO,COUNT(*),
SUM(A.MARK)
FROM GKK.MARK_DTL A,
( SELECT MAX(LAT_ENT_TP) ENDTP
FROM GKK.LOAD_DTL ) AS B,
( SELECT MAX(LAT_BEG_TP) BEGTP
FROM GKK.LOAD_DTL ) AS C
WHERE LAT_TP <= B.ENDTP AND LAT_TP >= C.BEGTP
GROUP BY A.ROLLNO; |
Edited - poster needs to learn to use the "Code" tag |
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dick scherrer
Moderator Emeritus
Joined: 23 Nov 2006 Posts: 19244 Location: Inside the Matrix
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Hello,
Quote: |
LAT_TP is present in Index |
Being in an index is far less important than being the high-order part of an index. . .
What happens when you execute these queries? |
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callkris_cit
New User
Joined: 22 Apr 2006 Posts: 44
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Query 2 execute faster than query 1 |
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