Here is handy steps for any UNDO tablespace issue. Some example are : * undo tablespace was dropped * undo was not recreated * undo was recreated without specifying 'undo' keyword. To resolve the issue, Follow the following steps : 1. set undo_management to MANUAL 2. startup pfile 3. drop undo tablespace (If it was created wrongly without undo keyword) 4. create undo tablespace undotbs datafile '??????' size 1M reuse; 5. shutdown database. 6. set undo_management to AUTO- 7. startup Scott Washburn Oracle Database Administrator Wolseley North America Division 12500 Jefferson Ave Newport News * VA * 23602-4314 T: +1 (757) 223-6404 F: +1 (757) 989 2501 E: scott.washburn@xxxxxxxxxxxx <mailto:scott.washburn@xxxxxxxxxxxx> www.wolseley.com <http://www.wolseley.com> Wolseley plc registered office Parkview 1220 Arlington Business Park Theale Nr Reading Rg7 4GA United Kingdom Registration No. 29846 England ________________________________ From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Srinivas Chintamani Sent: Monday, April 21, 2008 9:16 AM To: oracle-l@xxxxxxxxxxxxx Subject: <URGENT> How do I recover when the UNDO tablespace data file is corrupt? </URGENT> Hi All, I am getting the following errors when I am trying to open my database. There was a power failure to the server over the weekend, that caused me all of this messs. Here are the errrors: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ORA-01122: database file 2 failed verification check ORA-01110: data file 2: 'C:\ORACLE\ORADATA\TRACS3\UNDOTBS01.DBF' ORA-01200: actual file size of 83976 is smaller than correct size of 138240 blocks - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Does anybody have any ideas on how to get my db started back? The last known good back up is about a month-and-a-half old. All other datafiles seem to be ok. I would really appreciate any help on getting my database up. -- Regards, Srinivas Chintamani