It may happen that we might have an Oracle database crash power down situations and Oracle never comes up. Oracle might never come up due to corrupt
block or any other issues. There may be errors like ORA-01578 or corruption.
There are some simple steps we need to follow
SQL>sqlplus / as
sysdba
SQL> shutdown
immediate
SQL> startup nomount
SQL>alter
database open;
If all these steps go through without any issues then you
the lucky person and there are no issues.
In case there is a real corruption we may have to recover
the database In this Situation we need to recover the database using REDO logs.
Follow below steps
Take a backup of the entire OCU folder
SQL>sqlplus / as
sysdba
SQL> shutdown
immediate
SQL> startup nomount
SQL> SELECT
MEMBER FROM V$LOG G, V$LOGFILE F WHERE G.GROUP# = F.GROUP# AND G.STATUS = 'CURRENT';
This query outputs the
path of the redo log that we need to submit in the next query.
SQL>recover
database until cancel
In this step you
should the path the is obtained in the above step
SQL>alter
database open resetlogs;
If none of the above work then we need to create a new set
of control files in addition to the above steps,
Follow below steps
Take a backup of the entire OCU folder and delete the .CTL
files from the OCU folder.
SQL>sqlplus / as
sysdba
SQL> shutdown
immediate
SQL> startup nomount
SQL>CREATE
CONTROLFILE REUSE DATABASE "WIND" RESETLOGS NOARCHIVELOG
MAXLOGFILES 16
MAXLOGMEMBERS 3
MAXDATAFILES 100
MAXINSTANCES 8
MAXLOGHISTORY 292
LOGFILE
GROUP 1 'D:\ptc\Windchill_9.1\ocu\oradata\wind\WINDREDO01.LOG' SIZE 100M,
GROUP 2 'D:\ptc\Windchill_9.1\ocu\oradata\wind\WINDREDO02.LOG' SIZE 100M,
GROUP 3 'D:\ptc\Windchill_9.1\ocu\oradata\wind\WINDREDO03.LOG' SIZE 100M
DATAFILE
'D:\ptc\Windchill_9.1\ocu\oradata\wind\WINDBLOBS01.DBF',
'D:\ptc\Windchill_9.1\ocu\oradata\wind\WINDINDEX01.DBF',
'D:\ptc\Windchill_9.1\ocu\oradata\wind\WINDSYSAUX01.DBF',
'D:\ptc\Windchill_9.1\ocu\oraata\wind\WINDSYSTEM01.DBF',
'D:\ptc\Windchill_9.1\ocu\oradata\wind\WINDUNDOTBS01.DBF',
'D:\ptc\Windchill_9.1\ocu\oradata\wind\WINDUSERS01.DBF',
'D:\ptc\Windchill_9.1\ocu\oradata\wind\WINDWCAUDIT01.DBF'
;
SQL> SELECT
MEMBER FROM V$LOG G, V$LOGFILE F WHERE G.GROUP# = F.GROUP# AND G.STATUS = 'CURRENT';
This query outputs the
path of the redo log that we need to submit in the next query.
SQL>recover
database until cancel
In this step you
should the path the is obtained in the above step
SQL>alter
database open resetlogs;
These all 3 methods usually suffice to recover a crashed
database. But if even these 3 methods donot recover your database then you need
to get in touch with a database expert.
