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Query optimisation

 
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raak

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Joined: 23 May 2006
Posts: 166
Location: chennai

PostPosted: Thu Jan 10, 2008 9:52 am    Post subject: Query optimisation
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Is there any way that this query can be optimised??


SELECT B.SOC_SEC_NUM || ';' ||
B.LAST_NAME || ';' ||
B.FIRST_NAME || ';' ||
IFNULL(CHAR (B.BRTH_BIRTH_D), ' ') || ';' ||
B.GROUP_NUMBER || ';' ||
C.GROUP_NAME
FROM EMP_TABLE B
JOIN
GRP_TABLE C
ON B.GROUP_NUMBER = C.GROUP_NUMBER
WHERE B.PART_KEY IN
(
SELECT DISTINCT A.PART_KEY
FROM PAY_TABLE A
WHERE A.PAY_D > CURRENT DATE - 6 MONTHS
)
AND
B.PAY_STATUS IN
('00', '01', '07')
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stodolas

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Joined: 13 Jun 2007
Posts: 632
Location: Wisconsin

PostPosted: Thu Jan 10, 2008 6:28 pm    Post subject:
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Probably. Have you run an explain on it?
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raak

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Joined: 23 May 2006
Posts: 166
Location: chennai

PostPosted: Thu Jan 10, 2008 6:41 pm    Post subject:
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ya.. it was saying that DISTINCT should be avoided and Nonqualified function ( I think it is the IFNULL condition) should also be avoided.

but I am creating a report out of this and DISTINCT cannot be avoided since there is gud possibility of duplicates occuring in that field.


Any thoughts on this???
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