Enable LOCAL_UNDO for PDBs

Starting with 12.2, we can enable LOCAL_UNDO for each PDBs while creating an Oracle database as Container, and if we forget it then we can ebale this option after creation:

Check if the option is enabled or not:

SQL> SELECT property_name, property_value FROM database_properties WHERE property_name = 'LOCAL_UNDO_ENABLED'; 

no rows selected

Note: No rows means this option is disabled

SQL> select con_id, tablespace_name from   cdb_tablespaces where  contents = 'UNDO' order by con_id;

    CON_ID TABLESPACE_NAME
---------- ------------------------------
         1 UNDOTBS

Note. Just we have an UNDO tablespace in the CDB$ROOT as CON_ID=1

Enable LOCAL_UNDO: with startup upgrade mode

SQL> shut immediate
SQL> startup upgrade
SQL> alter database local undo on;
SQL> shut immediate
SQL> startup 

Check again the enabled option:

SQL> select property_name, property_value from   database_properties where  property_name = 'LOCAL_UNDO_ENABLED';
PROPERTY_NAME                PROPERTY_VALUE
-----------------------      -----------------------
LOCAL_UNDO_ENABLED           TRUE

Check the Undo tablespaces:

SQL> select con_id, tablespace_name from   cdb_tablespaces where  contents = 'UNDO' order by con_id;

    CON_ID TABLESPACE_NAME
---------- ------------------------------
         1 UNDOTBS
         3 UNDO_1
         4 UNDO_1

Enjoy!