| SET THE OPTIMAL VAULES OF UNDO SEGMENT [message #166569] |
Fri, 07 April 2006 00:42  |
raddisonlee
Messages: 29
Registered: March 2005
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Junior Member |
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HI ,
I SET MY DATABASE(9.2.0.1) UNDO_MANAGEMENT=AUTO ,
AND UNDO TABLESPACE =UNDOTBS01 ,
NOW , WHEN I RUN A LONG TRANSACTION (JUST INSERT TO A TABLE WITHOUT INDEX) 40 million ROWS , AMONG ROLLBACK SEGMENT
_SYSMUN9$ HAVE BEEN GROW UP TO 300 MEGA . AND I WANNA SET A OPTIMAL VALUES TO CONTROL THE SIZE OF ROLLBACK , MAY I ?
AND UNDER UNDO AUTO MANAGEMENT MODE , CAN I SHRINKS THE ROLLBACK SEGMENTS BY MANNUL ??? IF AUTO SHRINKS ROLLBACK SPACE?
WHEN ? IS THERE A PARAMETER TO SET ? THANKS
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| Re: SET THE OPTIMAL VAULES OF UNDO SEGMENT [message #166577 is a reply to message #166569] |
Fri, 07 April 2006 01:21  |
aciolac
Messages: 242
Registered: February 2006
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Senior Member |
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When database is in Automatic Undo Managment, then You cannot chane anything in the managment of rollback segments. You cannot add, delete or alter them. Oracle database make his decisions and change parametrs of rollback segments automatically as they requiered.
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| Re: SET THE OPTIMAL VAULES OF UNDO SEGMENT [message #166578 is a reply to message #166569] |
Fri, 07 April 2006 01:38 |
raddisonlee
Messages: 29
Registered: March 2005
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Junior Member |
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really ?
1 .undo auto manage and mannul manage tow mode exists together ? can it ?
2 .if in UAM mode , why i see that there are 10 rollback segment ? and if my oltp system will occurs for large amount transaction appear together , can i increase the number of rollback segments over 10 by mannul ?
3 .is that oracle set null in each rollback segments for undo tablespace setup on AUM mode ?? so none can change it ???
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| Re: SET THE OPTIMAL VAULES OF UNDO SEGMENT [message #166581 is a reply to message #166578] |
Fri, 07 April 2006 02:05 |
aciolac
Messages: 242
Registered: February 2006
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Senior Member |
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really.
1)when You set UNDO_MANAGEMENT={manual|AUTO} then You set ONE of possible undo managments. You cannot use them both at one time.
2)Thing, that You have 10 rbs meant that Oracle decided to have then so many  . Yet once repeat: when database is in Automatic Undo Managment, then You cannot chane anything in the managment of rollback segments.
3) see p. 2)
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