T 4.28 Loss of data in a database

Loss of data in a database can be caused by a wide variety of factors, including inadvertent manipulation of data (for example, through unintentional deletion of data), database crashes and deliberate intrusions.

As a result, the availability and completeness of the data is no longer guaranteed, and the following consequences might arise:

• Applications which rely on the data in the database can no longer be executed or offer only partial function..

• The correlation of data is lost.

• Considerable time and effort are required to recover lost data.

Depending on the cause of the data loss, it can be difficult or even impossible to determine precisely which data has been lost. This can lead to further financial losses and security risks.

Example:

When a database model is changed, the old tables and structures must first be saved and deleted. Then the new tables are created. The occurrence of an error during any of these procedures can easily cause data to be lost or render it incapable of transfer.