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Home -> Community -> Mailing Lists -> Oracle-L -> RE: Long-running SQL
<<It is using the index. Range scans are not "smart" so to speak. In
Harrison's sql tuning book, he states that a range scan is not
intelligent.>>
Well, depends on the type of range scan. There are two kinds, bonded and unbounded. Bounded is indeed intelligent and starts and stops at specific points. This kind of range scan you will find, for example, when the WHEN clause contains something like:
where range_id > 100 and range_id < 300
An unbounded range scan, starts at a specific place in the index and reads basically the remainder of the index. A bounded range scan is caused by such actions like
Where range_id > 100
RF
Robert G. Freeman - Oracle8i OCP
Oracle DBA Technical Lead
CSX Midtier Database Administration
The Cigarette Smoking Man: Anyone who can appease a man's conscience can take his freedom away from him.
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Please see the official ORACLE-L FAQ: http://www.orafaq.com
--
Author: Freeman, Robert
INET: Robert_Freeman_at_csx.com
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