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Tuning option selection (merged 2) [message #511071] Thu, 09 June 2011 07:12 Go to next message
a_oracle
Messages: 98
Registered: November 2010
Member
Hi,
New to tuning terminologies so need your expertise.
Just a general question :--
I have a query which I tuned using two methods:
Method 1: executed query in milliseconds,say 219 milliseconds but the cost is more.
Method 2: executed the query taking slightly more time(say,600 milliseconds) than method 1 but the cost is less.

Now, seeing the performance currently of the tuned query, I can apply any, but need your advice as which method is the best. Should we consider selecting the tuned query which takes minimal cost or the other one.
Re: Tuning option selection (merged 2) [message #511073 is a reply to message #511071] Thu, 09 June 2011 07:28 Go to previous messageGo to next message
cookiemonster
Messages: 13917
Registered: September 2008
Location: Rainy Manchester
Senior Member
Never read too much into cost - it's an approximation of how much work oracle thinks it's going to take and depends on lots of factors.
I'd be more interested in the time. However your times are probably within margin of error.
So get more data in the tables so it takes longer and compare again.
Re: Tuning option selection (merged 2) [message #511664 is a reply to message #511071] Tue, 14 June 2011 08:17 Go to previous message
michael_bialik
Messages: 621
Registered: July 2006
Senior Member
Compare also the number of buffer gets and disk reads performed by each statement.

HTH.
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