Database Repair

How to Restore Lost Oracle Database Files from Backup

Oracle Database is composed of several important files that are necessary to run the application. The DB comprises of Control files, Tablespaces, Data Files, Server Parameter File (SPFILE) and many more. Tablespaces are the storage units which are used by Oracle to save data and media. So, if the Oracle DB gets corrupt then the first thing to do is recover Oracle tablespaces and data files. Oracle Database files can be recovered manually using RMAN or with a professional Oracle Database Recovery software.

The one thing that is to remember that the data should be restored on a new location. As the original location may be damaged or under the influence of corruption, saving files to this location will corrupt it. So, it is advised to restore the files at a safe location. Here we will use RMAN commands and restore/ recover files from backup and later know about the features of Oracle DBF file repair tool for database recovery.

For Restoring Oracle Database to New Location

  • Specify the new names with RMAN SET NEWNAME command
  • Now use SWITCH command to update control file and refer Datafiles with New names set
  • Once the names are set run the RESTORE TABLESPACE and RESTORE DATAFILE as normal and then make use of SET NEWNAME for the new location of file.
  • Remember Once the RESTORE command is run, specify the new names in control file before recovery
  • So, After RESTORE and before RECOVER, use SWITCH command to update the new file names
  • Use SWITCH DATAFILE ALL and update the control file to new names

Here is an example of Restore and Recovery process. The example uses datafiles in tablespaces USERS and TOOLS from /Olddisk to /newdisk.

RUN

{

  SQL 'ALTER TABLESPACE users OFFLINE IMMEDIATE';

  SQL 'ALTER TABLESPACE tools OFFLINE IMMEDIATE';

  # specify the new location for each datafile

  SET NEWNAME FOR DATAFILE '/olddisk/users01.dbf' TO

                           '/newdisk/users01.dbf';

  SET NEWNAME FOR DATAFILE '/olddisk/tools01.dbf' TO

                           '/newdisk/tools01.dbf';

  # to restore to an ASM disk group named dgroup, use:

  # SET NEWNAME FOR DATAFILE '/olddisk/trgt/tools01.dbf'

  #     TO '+dgroup';

  RESTORE TABLESPACE users, tools;

  SWITCH DATAFILE ALL;   # update control file with new filenames

  RECOVER TABLESPACE users, tools;

}

Once the recovery completed successfully bring the tablespaces online by the following command

SQL 'ALTER TABLESPACE users ONLINE';

SQL 'ALTER TABLESPACE tools ONLINE';

So, this is the manual method to recover Oracle files from backup. But, it could cause errors if a single step is skipped and that’s why it is necessary to use a professional database recovery tool. As Oracle has large amount of data, No DBA will want to lose it with a silly mistake, the recovery software promises error free file recovery without any loss. So, repair the database and retrieve DBF file with Stellar Oracle Database Repair tool.

Features of Stellar Oracle Database Repair are

  • Easy and simple user interface
  • Recover XML Data and Schemas
  • Retrieve Tables, columns, schemas, stored procedures and other parameters
  • Compatible with Oracle 9i, 10g, or 11g
  • Recovers Deleted Records of Tables
  • Generates Log Report of the file
  • Display Preview After Scan
  • Can be installed on Windows 10/ 8/ 8.1/ 7

Try the Oracle database recovery tool and bring back the database to a normal state. Download the software for free and recover files.

Leave a Reply

Your email address will not be published. Required fields are marked *