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#1
October 16th, 2006, 06:37 AM
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Optimize Query with Left Join
Can anyone give me any tips on making this query perform better;
SELECT GROUP_UNITY.DESCRIPTION, Count(LOCATION.SERIAL_NUM) FROM LOCATION INNER JOIN SERIAL_NOS ON LOCATION.SERIAL_NUM = SERIAL_NOS.SERIAL_NUM LEFT JOIN GROUP_UNITY ON SERIAL_NOS.GROUP_REF = GROUP_UNITY.REF WHERE LOCATION.DATE_ENTER >= '09-Oct-2006' AND LOCATION.DATE_ENTER <= '14-Oct-2006' AND LOCATION.WAREHOUSE = 'ZZ' GROUP BY GROUP_UNITY.DESCRIPTION ORDER BY GROUP_UNITY.DESCRIPTION if i change the left join to an inner join it performs much better, but does not return all the records.
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#2
October 16th, 2006, 08:44 AM
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Can you check it's explain plan?
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