SQL> startup
ORACLE instance started.
 
Total System Global Area 1610612736 bytes
Fixed Size                  2177912 bytes
Variable Size             396149896 bytes
DATABASE Buffers         1207959552 bytes
Redo Buffers                4325376 bytes
DATABASE mounted.
ORA-01113: file 2 needs media recovery
ORA-01110: DATA file 2: '/oradata/oracle/ts/undotbs01.

commonly the database unable be startup if UNDO or SYSTEM table space need recovery, if these happen we need correct temporary workaround to handle this, all workaround for each tablespace datafile is similar

do the recovery

SQL> recover DATABASE;
ORA-00279: CHANGE 7516226638 generated at 05/05/2008 12:32:11
needed FOR thread 1
ORA-00289: suggestion : /oradata/oracle/ts/arc/1_42_653916655.dbf
ORA-00280: CHANGE 7516226638 FOR thread 1 IS IN sequence #42
 
Specify log: {ret=suggested | filename | AUTO | CANCEL}
AUTO
ORA-00308: cannot open archived log
‘/oradata/oracle/ts/arc/1_42_653916655.dbf’
ORA-27037: unable TO obtain file STATUS
SVR4 Error: 2: No such file OR directory
Additional information: 3

Open database

SQL> ALTER DATABASE open;
ALTER DATABASE open
*
ERROR at line 1:
ORA-01113: file 2 needs media recovery
ORA-01110: DATA file 2: '/oradata/oracle/ts/undotbs01.dbf'

this condition force us to append archivelog or logfile consist appropriate sequence, if there not available... database unable up till to ever

but we have a temporary solution, below :

• Edit Init file
  Remark parameter undo_management dan undo_tablespace
  add this parameter :
  UNDO_MANAGEMENT=MANUAL
_ALLOW_RESETLOGS_CORRUPTION = TRUE
_ALLOW_ERROR_SIMULATION = TRUE
_CORRUPTED_ROLLBACK_SEGMENTS =(_SYSSMU1,_SYSSMU2,_SYSSMU3, ...)
• get value _CORRUPTED_ROLLBACK_SEGMENTS from [OS] the command cd system_datafile_directory
strings system01.dbf | grep _SYSSMU | cut -d $ -f 1 | sort -u
• shutdown database , and turn on with that initfile already edited. Pfile must be wrote in startup command .

  SQL> startup mount
  pfile='/data1/oracle/product/10.2.0/dbs/initts.ora';
  ORACLE instance started.
  Total System Global Area 1610612736 bytes
  Fixed Size                  2177912 bytes
  Variable Size             396149896 bytes
  DATABASE Buffers         1207959552 bytes
  Redo Buffers                4325376 bytes
  DATABASE mounted.

• Recover database until cancel

  SQL> recover DATABASE until cancel;
  ORA-00279: CHANGE 7516226638 generated at 05/05/2008 12:32:11
  needed FOR thread 1
  ORA-00289: suggestion :
  /oradata/oracle/ts/arc/1_42_653916655.dbf
  ORA-00280: CHANGE 7516226638 FOR thread 1 IS IN sequence #42
  Specify log: {ret=suggested | filename | AUTO | CANCEL}
  CANCEL
  ORA-01547: warning: RECOVER succeeded but OPEN RESETLOGS would get error below
  ORA-01194: file 1 needs more recovery TO be consistent
  ORA-01110: DATA file 1: ‘/oradata/oracle/ts/system01.dbf’
  ORA-01112: media recovery NOT started

• Open database

  SQL> ALTER DATABASE OPEN RESETLOGS;
  DATABASE altered.

after the database up, backup important data using exp/imp