Comments on: Upgrade to 10gR2 and Undo Retention Changes

By: Alex Gorbachev

Alex Gorbachev — Mon, 23 Jul 2007 16:50:37 +0000

Venkat, I suggest you re-read the post once again. You’d find there the answer to your question.

By: Venkat.S

Venkat.S — Thu, 19 Jul 2007 08:33:54 +0000

Hi,
In our cutomer production box the undo tablespace size is 200GB and it is now only having 6 GB free space. There are no active transactions and and the UNDO_RETENTION period is 8 hours. But the problem is the UNDO space is not geting freed up after 2 days also. 2 days before the used space is 193 GB and still it is in the same position. The UNDO_RETENTION period is 8 hours and the EXTENT_MANAGEMENT is Manual. Please suggest how to free up the space ?

By: Shervin Sheidaei

Shervin Sheidaei — Wed, 20 Jun 2007 03:45:09 +0000

Comment from 10g admin doc :

Under certain circumstances, you must set the undo retention period by setting the
UNDO_RETENTION initialization parameter. The only time you must set this parameter
is when:
â– The undo tablespace has the AUTOEXTEND option enabled
â– You want to set undo retention for LOBs
â– You want retention guarantee

In all other cases, this parameter is ignored, and the database automatically tunes for maximum undo retention.

By: Shervin

Shervin — Wed, 20 Jun 2007 03:39:59 +0000

Let me add some comments from 10g Admin doc :
Under certain circumstances, you must set the undo retention period by setting the
UNDO_RETENTION initialization parameter.
The only time you must set this parameter is when:
â– The undo tablespace has the AUTOEXTEND option enabled
â– You want to set undo retention for LOBs
â– You want retention guarantee
In all other cases, this parameter is ignored, and the database automatically tunes for maximum undo retention