Recovery from Corrupted/deleted Undo datafile without backup, after last Clean Shutdown in NOARCHIVE/ARCHIVE mode.

Transcription

1 Recovery from Corrupted/deleted Undo datafile without backup, after last Clean Shutdown in NOARCHIVE/ARCHIVE mode. After last clean shutdown, while restarting DB we see database not coming up and found datafile to corrupted/deleted. In this case steps remain same for Archive and NoArchive mode. Contents 1) Check DB is NOArchive mode and Clean Shutdown DB ) Corrupt the UNDO datafile Simulate the scenario ) Now Start the DB, and initiate recover database command as below ) Try to Offline the corrupted undo Datafile and open Database ) Change the undo_management to Manual parameters and Restart DB ) Drop undo tablespace ) Create undo TBS, Reset undo_management to AUTO and restart the DB ) Re-check if the Parameters were unset ) Verify the user data and database Page 1 of 8

2 1) Check DB is NOArchive mode and Clean Shutdown DB SQL> select,open_mode,log_mode from v$database; OPEN_MODE LOG_MODE D041 READ WRITE NOARCHIVELOG SQL> archive log list Database log mode No Archive Mode Automatic archival Disabled Archive destination C:\Oracle\oradata\d041\arch Oldest online log sequence 24 Current log sequence 26 SQL> shut immediate; Database closed. Database dismounted. ORACLE instance shut down. 2) Corrupt the UNDO datafile Simulate the scenario C:\Oracle\oradata\d041>dbv FILE=UNDOTBS01.DBF DBVERIFY: Release Production on Sun Dec 29 11:17: Copyright (c) 1982, 2009, Oracle and/or its affiliates. All rights reserved. DBVERIFY - Verification starting : FILE = C:\ORACLE\ORADATA\D041\UNDOTBS01.DBF DBVERIFY - Verification complete Total Pages Examined : 2560 Total Pages Processed (Data) : 0 Total Pages Failing (Data) : 0 Total Pages Processed (Index): 0 Total Pages Failing (Index): 0 Total Pages Processed (Other): 168 Total Pages Processed (Seg) : 20 Total Pages Failing (Seg) : 0 Total Pages Empty : 2392 Total Pages Marked Corrupt : 0 Total Pages Influx : 0 Total Pages Encrypted : 0 Highest block SCN : ( ) Now Corrupt Undo file ================================ Manually adding data to undo file to the end of file to simulate corruption. C:\Oracle\oradata\d041>echo A >> UNDOTBS01.DBF C:\Oracle\oradata\d041>dbv FILE=UNDOTBS01.DBF DBVERIFY: Release Production on Sun Dec 29 11:18: Copyright (c) 1982, 2009, Oracle and/or its affiliates. All rights reserved. DBV-00600: Fatal Error - [21] [5] [0] [0] OR If you Edit using the Edit plus, and delete some content from middle of file. C:\Oracle\oradata\d041>dbv FILE=UNDOTBS01.DBF DBVERIFY: Release Production on Sun Dec 29 10:35: Copyright (c) 1982, 2009, Oracle and/or its affiliates. All rights reserved. DBV-00102: File I/O error on FILE (C:\ORACLE\ORADATA\D041\UNDOTBS01.DBF) during end read operation (7680) Page 2 of 8

3 3) Now Start the DB, and initiate recover database command as below. SQL> startup ORACLE instance started. Total System Global Area bytes Fixed Size bytes Variable Size bytes Database Buffers bytes Redo Buffers bytes Database mounted. ORA-01157: cannot identify/lock data file 3 - see DBWR trace file ORA-01110: data file 3: 'C:\ORACLE\ORADATA\D041\UNDOTBS01.DBF' SQL> select,open_mode,log_mode from v$database; OPEN_MODE LOG_MODE D041 MOUNTED NOARCHIVELOG Whenever DB shuts cleanly, CHECKPOINT_CHANGE# and LAST_CHANGE# must always be sync else they need to do crash/media recovery, as below SQL> set line 200 col LAST_TIME for a25 col name for a45 select,status,checkpoint_change#,last_change#,to_char(last_time,'dd-mon-yyyy HH24:MI:SS') LAST_TIME from v$datafile; STATUS CHECKPOINT_CHANGE# LAST_CHANGE# LAST_TIME C:\ORACLE\ORADATA\D041\SYSTEM01.DBF SYSTEM DEC :58:30 C:\ORACLE\ORADATA\D041\SYSAUX01.DBF DEC :58:30 C:\ORACLE\ORADATA\D041\UNDOTBS01.DBF DEC :58:30 C:\ORACLE\ORADATA\D041\USERS01.DBF DEC :58:30 C:\ORACLE\ORADATA\D041\EXAMPLE01.DBF DEC :58:30 SQL> recover database; ORA-00283: recovery session canceled due to errors ORA-01110: data file 3: 'C:\ORACLE\ORADATA\D041\UNDOTBS01.DBF' ORA-01157: cannot identify/lock data file 3 - see DBWR trace file ORA-01110: data file 3: 'C:\ORACLE\ORADATA\D041\UNDOTBS01.DBF' SQL> set line 200 col error for a20 select * from v$recover_file; FILE# _ ERROR CHANGE# TIME FILE NOT FOUND 0 Page 3 of 8

4 4) Try to Offline the corrupted undo Datafile and open Database. SQL> alter database datafile 3 offline; (Use this for Archive Log Mode) alter database datafile 3 offline * ERROR at line 1: ORA-01145: offline immediate disallowed unless media recovery enabled SQL> alter database datafile 3 offline for drop; (Use this for NOArchive Log Mode) Database altered. SQL> alter database open; Database altered. SQL> select name,open_mode from v$database; OPEN_MODE D041 READ WRITE SQL> select * from v$recover_file; FILE# _ ERROR CHANGE# TIME OFFLINE OFFLINE FILE NOT FOUND 0 SQL> col name for a45 set line 200 select name,status from v$datafile; STATUS C:\ORACLE\ORADATA\D041\SYSTEM01.DBF SYSTEM C:\ORACLE\ORADATA\D041\SYSAUX01.DBF C:\ORACLE\ORADATA\D041\UNDOTBS01.DBF OFFLINE C:\ORACLE\ORADATA\D041\USERS01.DBF C:\ORACLE\ORADATA\D041\EXAMPLE01.DBF SQL> drop tablespace undotbs1 including contents and datafiles; drop tablespace undotbs1 including contents and datafiles * ERROR at line 1: ORA-30013: undo tablespace 'UNDOTBS1' is currently in use On checking parameter undo_management found to be AUTO as below, so it is not all allowing to Drop. SQL> show parameter undo TYPE VALUE undo_management string AUTO Page 4 of 8

5 undo_tablespace string UNDOTBS1 SQL> show parameter rollback_segments TYPE VALUE rollback_segments string 5) Change the undo_management to Manual parameters and Restart DB SQL> alter system set undo_management='manual' scope=spfile; System altered. SQL> alter system set rollback_segments=system scope=spfile; System altered. SQL> shut immediate; Database closed. Database dismounted. ORACLE instance shut down. SQL> Startup ORACLE instance started. Total System Global Area bytes Fixed Size bytes Variable Size bytes Database Buffers bytes Redo Buffers bytes Database mounted. Database opened. SQL> select * from v$recover_file; FILE# _ ERROR CHANGE# TIME OFFLINE OFFLINE FILE NOT FOUND 0 SQL> select name,status from v$datafile; STATUS C:\ORACLE\ORADATA\D041\SYSTEM01.DBF SYSTEM C:\ORACLE\ORADATA\D041\SYSAUX01.DBF C:\ORACLE\ORADATA\D041\UNDOTBS01.DBF OFFLINE C:\ORACLE\ORADATA\D041\USERS01.DBF C:\ORACLE\ORADATA\D041\EXAMPLE01.DBF SQL> SELECT SEGMENT_, XACTS ACTIVE_TX, V.STATUS FROM V$ROLLSTAT V, DBA_ROLLBACK_SEGS WHERE TABLESPACE_ = 'UNDOTBS1' AND SEGMENT_ID = USN; no rows selected Page 5 of 8

6 6) Drop undo tablespace. SQL> drop tablespace undotbs1 including contents and datafiles; Tablespace dropped. SQL> select * from v$rollname ; USN SYSTEM SQL> select SEGMENT_,SEGMENT_ID,status,tablespace_name from dba_rollback_segs ; SEGMENT_ SEGMENT_ID STATUS TABLESPACE_ SYSTEM 0 SYSTEM 7) Create undo TBS, Reset undo_management to AUTO and restart the DB. SQL> select * from v$tablespace; TS# INC BIG FLA ENC SYSTEM YES NO YES 1 SYSAUX YES NO YES 4 USERS YES NO YES 3 TEMP NO NO YES 6 EXAMPLE YES NO YES SQL> create undo tablespace UNDOTBS1 datafile 'C:\ORACLE\ORADATA\D041\UNDOTBS01.DBF' size 20M reuse; Tablespace created. SQL> Alter System set undo_management=auto scope=spfile; System altered. SQL> Alter System Reset rollback_segments; System altered. SQL> show parameter undo TYPE VALUE undo_management string MANUAL undo_retention integer 900 undo_tablespace string UNDOTBS1 SQL> shut immediate; Database closed. Database dismounted. Page 6 of 8

7 ORACLE instance shut down. SQL> startup ORACLE instance started. Total System Global Area bytes Fixed Size bytes Variable Size bytes Database Buffers bytes Redo Buffers bytes Database mounted. Database opened. 8) Re-check if the Parameters were unset. SQL> show parameter rollback_segments TYPE VALUE rollback_segments string SQL> show parameter undo TYPE VALUE undo_management string AUTO undo_retention integer 900 undo_tablespace string UNDOTBS1 SQL> select SEGMENT_,SEGMENT_ID,status,tablespace_name from dba_rollback_segs ; SEGMENT_ SEGMENT_ID STATUS TABLESPACE_ SYSTEM 0 SYSTEM _SYSSMU20_ $ 20 UNDOTBS1 _SYSSMU19_ $ 19 UNDOTBS1 _SYSSMU18_ $ 18 UNDOTBS1 _SYSSMU17_ $ 17 UNDOTBS1 _SYSSMU16_ $ 16 UNDOTBS1 _SYSSMU15_ $ 15 UNDOTBS1 _SYSSMU14_ $ 14 UNDOTBS1 _SYSSMU13_ $ 13 UNDOTBS1 _SYSSMU12_ $ 12 UNDOTBS1 _SYSSMU11_ $ 11 UNDOTBS1 11 rows selected. SQL> SELECT SEGMENT_, XACTS ACTIVE_TX, V.STATUS FROM V$ROLLSTAT V, DBA_ROLLBACK_SEGS WHERE TABLESPACE_ = 'UNDOTBS1' AND SEGMENT_ID = USN; SEGMENT_ ACTIVE_TX STATUS _SYSSMU11_ $ 0 _SYSSMU12_ $ 0 _SYSSMU13_ $ 0 _SYSSMU14_ $ 0 _SYSSMU15_ $ 0 Page 7 of 8

8 _SYSSMU16_ $ _SYSSMU17_ $ _SYSSMU18_ $ _SYSSMU19_ $ _SYSSMU20_ $ rows selected. 9) Verify the user data and database. SQL> conn scott/tiger Connected. SQL> set line 200 select * from emp; EMPNO E JOB MGR HIREDATE SAL COMM DEPTNO SMITH CLERK DEC ALLEN SALESMAN FEB WARD SALESMAN FEB JONES MANAGER APR MARTIN SALESMAN SEP BLAKE MANAGER MAY CLARK MANAGER JUN SCOTT ANALYST APR KING PRESIDENT 17-NOV TURNER SALESMAN SEP ADAMS CLERK MAY JAMES CLERK DEC FORD ANALYST DEC MILLER CLERK JAN rows selected. SQL> col name for a45 select name,status from v$datafile; STATUS C:\ORACLE\ORADATA\D041\SYSTEM01.DBF SYSTEM C:\ORACLE\ORADATA\D041\SYSAUX01.DBF C:\ORACLE\ORADATA\D041\UNDOTBS01.DBF C:\ORACLE\ORADATA\D041\USERS01.DBF C:\ORACLE\ORADATA\D041\EXAMPLE01.DBF SQL> select * from v$recover_file; no rows selected Page 8 of 8