将rollback segment 改为UNDO tablespace.

参考文档： SAP Note 600141

SQL> create undo tablespace PSAPUNDO   datafile '/oracle/UP1/sapdata1/undo_1/undo.data1' size 2000 M reuse
         autoextend off;    (注：不能用SAPDBA建立，否则DB会起不来）

Remark: An Undo tablespace always has the following attributes
   - extent management:        LOCAL (LMTS)
   - allocation type:          SYSTEM (autoallocate)
   - segment space management: MANUAL

ADD following parameter in  /oracle/UP1/920_64/dbs/initUP1.ora
 
 undo_tablespace = PSAPUNDO

undo_retention = 43200 # 12h as start value

undo_management = AUTO

Delete following lines from initSID.ora

   Parameter: 'rollback_segments'
   Parameter: 'transactions' 
   Parameter: 'transactions_per_rollback_segment'
   Parameter: 'max_rollback_segments'

SQL> shutdown immediate;
SQL> startup mount;
SQL> alter database open;
SQL> DROP ROLLBACK SEGMENT <name>;

DROP ROLLBACK SEGMENT PRS_0;
DROP ROLLBACK SEGMENT PRS_1;
DROP ROLLBACK SEGMENT PRS_2;
DROP ROLLBACK SEGMENT PRS_3;
DROP ROLLBACK SEGMENT PRS_4;
DROP ROLLBACK SEGMENT PRS_5;
DROP ROLLBACK SEGMENT PRS_6;
DROP ROLLBACK SEGMENT PRS_7;
DROP ROLLBACK SEGMENT PRS_8;
DROP ROLLBACK SEGMENT PRS_9;
DROP ROLLBACK SEGMENT PRS_10;
DROP ROLLBACK SEGMENT PRS_11;
DROP ROLLBACK SEGMENT PRS_12;
DROP ROLLBACK SEGMENT PRS_13;
DROP ROLLBACK SEGMENT PRS_14;
DROP ROLLBACK SEGMENT PRS_15;
DROP ROLLBACK SEGMENT PRS_16;
DROP ROLLBACK SEGMENT PRS_17;
DROP ROLLBACK SEGMENT PRS_18;
DROP ROLLBACK SEGMENT PRS_19;

SQL> DROP TABLESPACE PSAPROLL including contents and datafiles;

手工在操作系统下删除相关的文件目录。