Mahendra

• Sep 2nd, 2005

 

Used to store undo data. In a transaction when data is updated , other seesions should not view the uncommited data . Other Sessions will access the undo dara in the Roll Back segment

anandhi80

 Profile Answers by anandhi80 

• Jun 28th, 2006

 

when a user updated a particular table (for example 100 rows)...the old value will be retained in the roll back segments(Oracle 8) and now it is Undo segment (oracle 9i). If the user issue a rollback command the old value will be taken from the rollback segment(that too if undo_retention parameter set properly in the parameter file).