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Go Back  dBforums > Database Server Software > DB2 > index reverse scan

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Old 12-09-10, 04:47
Pawan Kumar Pawan Kumar is offline
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index reverse scan
Hi ,
Can anyone tell me how index reverse scan actually work with example?
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Pawan Kumar
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Old 12-09-10, 08:37
dav1mo dav1mo is offline
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It, basically, means that DB2 knows you have column_x in this index sorted as ASCENDING, so when you ask for max(column_x) it starts at the end of the tree, instead of the beginning of the tree. It can, also, allow you to avoid a sort if you have ORDER BY column_x DESC, if that index is used by the access path.
Dave
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