Configuring Local Undo AND Configuring Shared Undo

Configuring Local Undo:

Shtudown the instance:

SQL> shutdown immediate;

SQL> startup upgrade;

SQL> show con_name

CON_NAME

-----------------------------

CDB$ROOT

Change the Undo mode to “Local Undo”:

SQL> alter database local undo on;

Reboot the instance:

SQL> shutdown immediate;

SQL> startup;

Verify that the Local Undo is now used:

SQL> SELECT PROPERTY_NAME, PROPERTY_VALUE FROM DATABASE_PROPERTIES WHERE PROPERTY_NAME = 'LOCAL_UNDO_ENABLED'

PROPERTY_NAME PROPERTY_VALUE

-------------------- ---------------

LOCAL_UNDO_ENABLED TRUE

Configuring Shared Undo

Shutdown the instance:

SQL> shutdown immediate;

SQL> startup upgrade;

SQL> show con_name

CON_NAME

------------------------------

CDB$ROOT

Change the Undo mode to “Shared Undo”:

SQL> alter database local undo off;

Reboot the instance:

SQL> shutdown immediate;

SQL> startup;

Verify that the new Undo mode is now used:

SQL> SELECT PROPERTY_NAME, PROPERTY_VALUE FROM DATABASE_PROPERTIES WHERE PROPERTY_NAME = 'LOCAL_UNDO_ENABLED'

PROPERTY_NAME PROPERTY_VALUE

-------------------- ---------------

LOCAL_UNDO_ENABLED FALSE