Data+integrity,+reliability,+redundancy

= Data Redundancy =


 * Data redundancy** occurs in database systems which have a field that is repeated in two or more tables. For instance, in case when customer data is duplicated and attached with each product bought then redundancy of data is a known source of inconsistency, since customer might appear with different values for given attribute. Data redundancy leads to data anomalies and corruption and generally should be avoided by design. Database normalization prevents redundancy and makes the best possible usage of storage. Proper use of foreign keys can minimize data redundancy and chance of destructive anomalies. However sometimes concerns of efficiency and convenience can result redundant data design despite the risk of corrupting the data.

= Data Integrity =

Refers to the validity of data. Data integrity can be compromised in a number of ways: Human errors when data is entered Errors that occur when data is transmitted from one computer to another Software bugs or viruses Hardware malfunctions, such as disk crashes Natural disasters, such as fires and floods There are many ways to minimize these threats to data integrity. These include: Backing up data regularly Controlling access to data via security mechanisms Designing user interfaces that prevent the input of invalid data Using error detection and correction software when transmitting data Data Reliability  Is the question whether databases are capable of performing at a good consistent level. It also refers to the authenticity of the data