Auto Undo Management in Oracle

Oracle 9 introduced a new way to manage rollback / undo data - an Undo Tablespace. To utilize Automatic Undo Management, create a tablespace in the database of type UNDO:

create undo tablespace UNDOTBS1 datafile '/U01/oradata/prod/undotbs_01.dbf'

extent management local uniform size 256k;

Next, modify your init file:

• UNDO_MANAGEMENT=AUTO

• UNDO_TABLESPACE=UNDOTBS1

• UNDO_RETENTION=<# of minutes>