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Bruno wrote:
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> Hi,
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> Can someone point me to a resource or share their experience on this subject?
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> What is the difference in response time for SELECT, INSERT and UPDATE on a table with regular index on a varchar2 column (all values uppercase) and the same table with the same index but this time function-based, with UPPER function on the same column (with mixed case values).
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> Will INSERT and UPDATE operations be slower with the function-based index? I would assume they should be, but am having hard time finding any resources. I am about to run some benchmarks on this, but am looking for a third-party opinion :-)
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>
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> Thanks!
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> Bruno
Its predominantly related to the cost of the function. If its a low cost expression, then you'll hardly notice the difference. If its (say) a custom plsql function that does 1000 things within in, then you'll certainly notice it.
hth
connor
-- Connor McDonald Co-author: "Mastering Oracle PL/SQL - Practical Solutions" ISBN: 1590592174 web: http://www.oracledba.co.uk web: http://www.oaktable.net email: connor_mcdonald_at_yahoo.com Coming Soon! "Oracle Insight - Tales of the OakTable" "GIVE a man a fish and he will eat for a day. But TEACH him how to fish, and...he will sit in a boat and drink beer all day" ------------------------------------------------------------Received on Thu Nov 11 2004 - 06:02:50 CST