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RE: OCP Architecture question

From: Stephen Lee <Stephen.Lee_at_DTAG.Com>
Date: Fri, 15 Aug 2003 06:34:24 -0800
Message-ID: <>


  1. Maybe, maybe not. To make a point, take it to a ridiculous extreme: Suppose you have a tablespace of 100M with two rollback segments made of 1M extents sizes. Then each segment must use 2M each (minextents must be at least 2) which means either segment could possibly grow to use 98M if needed
    (but not at the same time). Now make the extent sizes 25M. Then each
    segment uses 50M with no growth possibility. Now you don't have the ability to extend a segment to 98M; so this could be bad. But neither do you have a case where one segment can extend to 98M leaving the other poor segment stuck at 2M; so this could be good.

So .... "It Depends."  

2. I think this addresses a different issue; i.e. "failed to extend..."  

3. Essentially same reasoning as #1.  

4. Essentially same reasoning as #1.  

5. No comment needed.

-----Original Message-----
Sent: Thursday, August 14, 2003 8:24 PM
To: Multiple recipients of list ORACLE-L

Im using the self test software and here is a question... I dont like the answers. Please tell me if Im wrong.  

Which Three methods can be used to avoid snapshot too old errors. This is for the 8i test.  

  1. User larger extents
  2. Increase MAXEXTENTS for existing rollback segments
  3. Create rollback segments with higher optimal values
  4. Create rollback segments iwth high minextents
  5. Run long queries when transaction processing is high.

Ruling out 5 is obvious. The test says its.  


How does using large extents help this? What about a higher minextents value?

Please see the official ORACLE-L FAQ:
Author: Stephen Lee
  INET: Stephen.Lee_at_DTAG.Com

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Received on Fri Aug 15 2003 - 09:34:24 CDT

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