??: [SPAM] dynamic views cosnstency, do they use UNDO?

From: Serol_Luo \(BJ\) <Serol_Luo_at_smics.com>
Date: Tue, 5 Sep 2006 08:19:02 +0800
Message-ID: <B1B44026C565CF4F9753E28AAFB123CD018567@bjex108.smic-bj.com>

Some test can be built like below.  

Begin
For I in
(select * from v$session ) loop
 dbms_lock.sleep(...);
--- Fetch data, do something
end loop;    

---

Regards.
Serol Luo, From Peking,China
Or call me RollingPig
http://rollingpig.itpub.net  

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????: 2006?9?5? 6:14

???: oracle-l_at_freelists.org

??: [SPAM] dynamic views cosnstency, do they use UNDO?
???: ?
 

Hi  

Since v$ views based on x$ are memry structures I guess there is no guarantee that they would give a consistent view correct? For example in some busy systems, for example a 2500 users CRM system running joins of v$ views is time consuming, for example if I try to join v$sesstat with v$session it takes really a while.  

If let's say it takes 10 seconds does Oracle guarantee the values I am seeing are from 10 seconds ago? I am pretty sure undo is not used for memory structures or wrong?  

I Cant seem to find a easy way to test this.  

TIA   Alex      

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Received on Mon Sep 04 2006 - 19:19:02 CDT