Database Data Recovery – From SQL To Oracle
Loosing a singe file because of hard drive failure may have serious consequences. Imagine loosing a database on which rely thousands of users. Database is a complex system of files and applications that serve data to many users. Usually it is installed on some server that has a RAID disk system for data protection or uses SAN for storage. But even the most protected server system can fail. There are two general types of database failure:
- Database hardware malfunction
- Database system corruption
Database Hardware Malfunction
Any electronic device can fail. This applies also to big servers and huge disk arrays. They have redundant components to minimize the possibility of system failure but this is still not 100% fail-safe. Because of this even large databases need to have backups. Without proper (daily) backup we may run into trouble. Database data recovery is possible but involves two complex operations. Hard drive data recovery itself is not a simple task. RAID data recovery presents additional problems because all the files are distributed over many hard drives. And even when you painfully manage to recover data from all hard drives you still have to deal with database system corruption.
Database System Corruption
Since database is a system of files all of them need to be in perfect condition in order the database to function properly. Any error in some table may lead to problems accessing the database. Once the hardware is working you need to focus on the database itself. Database recovery involves checking all tables and repairing possible errors. While basic database repair is available in most database applications, for any major database failure you may need expert database data recovery service.
Database Data Recovery Services
Many companies specialize in data recovery with emphasis on databases. Each database stores megabytes of valuable information and when hardware fails or a bug in the application corrupts database tables you need data recovery experts to save the data. They will first make images of all the hard drives and them analyze each disk. Once the data from the disks will be rescued they will check all database tables for consistency and repair any errors due to hard drive failure or software bugs.
Most companies can restore data from popular database types: MS SQL, MySQL, Oracle, Exchange, SharePoint, Access, Lotus Notes, Sybase, etc. Database recovery goes beyond hard drive repair and data recovery. It is not enough to rescue few files from a single disk. There are may files that need to be in perfect shape for the database to work again. The data may be encrypted or password protected which further complicates data recovery. Database recovery services are not cheap but usually the price of loosing a database is much higher.
In addition to hardware/software failure and database corruption there are cases when you accidentally drop some table or delete data that you still need. In such cases the data is still in the database but is marked as deleted so you need either special database data recovery software or help from data recovery services.
In order to prevent data loss you need to use reliable hardware with enough redundancy to cope with standard failures. Typical computer components that fail are disk drives and power supplies. But even reliable hardware is not enough. Database servers are loaded with many queries—you need to regularly perform maintenance tasks to keep the database in good shape. But if the worst case happens and you lose data you can rely on database recovery experts.