S 2.135 Safe transfer of data to a database

Initiation responsibility: IT Security Officer, Head of IT

Implementation responsibility: Administrator

In many database systems, it is necessary for applications to accept the data from other systems. Basically, two different categories can be differentiated in principle:

Transfer of initial or old data

When transferring data from old systems, for example when a new database system has been purchased for use in the production environment, it must be ensured in particular that

• the data is available in a format that can be accepted in the destination database,
• the data is complete, i.e. there must be data available for all of the fields in the destination database to be filled with data, and
• the consistency and integrity of the data in the database are guaranteed.

A concept for the transfer of data must be drawn up specifying how the data to be transferred needs to be prepared and how the data transfer is to be performed in detail. Furthermore, a complete backup of the old data must be made. If the data is transferred in several steps, an independent data backup should be performed before each step.

Regular data transfers

If the destination database already contains data that must not be changed during the transfer or if data is transferred to a database at regular intervals,

• a full backup of the database must be performed before transferring the data,
• the data should be transferred outside of the regular office hours, if possible,
• precautions must be taken to prevent the same data from being transferred more than once,
• a concept must be drawn up before the first data transfer specifying how the data to be transferred needs to be prepared and/or how the data transfer should be performed in detail. In particular, this concept must also take into consideration how conflicts between the data already present in the destination database and the data to be transferred can be avoided, i.e. the extent to which the integrity and consistency of the destination database can be maintained.

Before updating a database, the users affected must be informed of the pending data transfer in due time, especially if it is expected that there will be limited database availability or longer database response times because of the update.

Before performing a data transfer, the actions to take in case of errors must be specified. For example, this includes whether or not the transfer should continue with the next record after a faulty record is detected or whether or not the entire data transfer must be cancelled. Furthermore, it is also necessary to specify how the data transfer will be resumed after it has been cancelled.

Review questions:

• Is there a concept for transferring data from other systems into an existing database?
• Is a full backup of the database made before transferring any data?
• Will the affected users be informed of a pending data transfer in due time and comprehensively?
• Has an approach as to how to handle errors during data transfer been defined?