Oracle Database Discussions

Hello,


I have a question regarding undo tablespace utilization. Currently there are no active transactions, all previous transactions have been commited, there is only one user session on my test database, undo retention is set to 900. I am trying to drop the old undo tablespace (I have created a new one, and switched to it - alter system undo_tablespace= new_undo;) but I get ORA-30013: undo tablespace 'old_undo' is currently in use.

I have bounced the database, but made no progress. dba_undo_extents stiil have active segments from the old_undo and dba_rollback_segs indicate there are two online segments from the old_undo.

Why is the old undo being used? WHo is using it?

Thank you and

Rgds