Data Recovery from databases

Data recovery is the process of restoring data that has been lost, accidentally deleted, corrupted or made inaccessible for any reason. In enterprise information technology (IT), data recovery typically refers to the restoration of data to a desktop, laptop, server, or external storage system from a backup.

A recovery-only file restore can be useful in the following situation:

A database is restored piecemeal. After restore of the primary file group is complete, one or more of the unrestored files are consistent with the new database state, perhaps because it has been read-only for some time. These files only have to be recovered; data copying is unnecessary.

A recovery-only restore operation brings the data in the offline file group online; no data-copy, redo, or undo phase occurs. The ability to restore databases from valid backups is a vital part of ensuring business continuity. Backup integrity and restorations are an important piece of the IT Governance Institute’s IT Control Objectives for Sarbanes-Oxley, 2nd Edition. In many instances, IT auditors merely confirm whether backups are being performed either to disk or to tape, without considering the integrity or viability of the backup media.

One of the key responsibilities of a database administrator (DBA) is to prepare for the possibility of media, hardware and software failure as well as to recover databases during a disaster. Should any of these failures occur, the major objective is to ensure that the database is available to users within an acceptable time period, while ensuring that there is no loss of data. DBAs should evaluate their preparedness to respond effectively to such situations by answering the following questions:

  • How confident is the DBA that the data on which the company business depends are backed up successfully and that the data can be recovered from these backups within the permissible time limits, per a service level agreement (SLA) or recovery time objective, as specified in the organization’s disaster recovery plan?

 

  • Has the DBA taken measures to draft and test the procedures to protect as well as recover the databases from numerous types of failures?

The following is a checklist for database backup and recovery procedures

  • Develop a comprehensive backup plan.
  • Perform effective backup management.
  • Perform periodic databases restore testing.
  • Have backup and recovery SLAs drafted and communicated to all stakeholders.
  • Have the disaster recovery plan (DRP) database portion drafted and documented.
  • Keep your knowledge and know-how on database and OS backup and recovery tools up to date.

A data recovery company in Houtston Texas has developed some advanced sql recovery techniques for the seriously damaged cases, they can be found at http://www.datanalyzers.com/houston-data-recovery/  Also, a well recommendable commercial sql data recovery software can be found at SQL Database Recovery Software

Either way I would recommend creating a backup copy before sending out the database to a specialized data recovery lab or even before attempting a do it yourself recovery (DIY) with some of the recomended software products. One of the main problems is that commercial sql recovery software will attempt to find corruptions within pages and if the application can not repair the page within the record, it will simply delete the page and record entry. This can sometimes leave the database in a state that is functional, but neverthelsess the relations of the database tables can produce undesired results when your front ent application attempts to query certain database records.

 

 

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