Dropping UNDO Tablespace

CREATE UNDO TABLESPACE APPS_UNDOTS2 DATAFILE '/u06/oratest/db/apps_st/data/undoo01.dbf' SIZE 2048M REUSE AUTOEXTEND OFF;

ALTER SYSTEM SET UNDO_TABLESPACE = APPS_UNDOTS2;

DROP TABLESPACE APPS_UNDOTS1;

SQL> ALTER SYSTEM SET UNDO_TABLESPACE = APPS_UNDOTS2(Optional);

System altered.

SQL> DROP TABLESPACE APPS_UNDOTS1;

Tablespace dropped.