RE: convert RBS tablespace from DMT to LMT (Oracle 8173) steps?

I just finished this conversion by using Ron's method: looping through RBS00X (X from 1 to 6):

alter rollback segment RBS00X offline;
drop rollback segment RBS00X;

create rollback segment RBS00X storage(initial 2048K next 2048K minextents 2 ) tablespace RBSlmt;
alter rollback segment RBS00X online;

select count(*) from all_objects where status = 'INVALID'; select SEGMENT_NAME ,STATUS from dba_rollback_segs;

I did not encount any problems.

Guang

-----Original Message-----
From: ml-errors_at_fatcity.com [mailto:ml-errors_at_fatcity.com]On Behalf Of Daniel Fink
Sent: Wednesday, July 23, 2003 3:25 PM
To: Multiple recipients of list ORACLE-L Subject: Re: convert RBS tablespace from DMT to LMT (Oracle 8173) steps?

Oracle will not let you drop a rollback segment if there are active transactions using it. However, it will allow you to offline the segment and no new transactions can use it. I don't recall the exact status in v$rollstat, but I think it may say pending offline.

As for the commit across cursors, the minute you commit, your transaction has ended, even if the cursor is still open. When you issue the next statement, you start a new transaction, which should assign you to a new rbs. The one you were using is still offline. Of course, if you online/assign/offline the rbs after each commit, you are reusing the rbs. I have not tested this, so I may be wrong (Thoughts, Kirti?). However, you may step on your own "free segment." Additionally, during the time period of the online/assign/offline, there is a chance that another transaction will be assigned to the rbs.

Daniel

Thomas Day wrote:
>
> How will you make sure that there are no active segments in your current
> rollback segments before you remove the datafiles with the OS? Even after
> you take the rollback segments off-line, Oracle will continue to use them
> as long as they have an active segment.
>
> BTW --- One way to help to avoid the ORA-01555 when you are committing
> across an open cursor is to take the rollback segment that that cursor is
> using off-line. No one else will come in a step on the "free" segment but
> your session will continue to process just fine until you close the
Received on Wed Jul 23 2003 - 13:53:57 CDT