Database Management Services

In the database management service, there exists a collection of interrelated files and a set of application programs to access and modify these files. The details of data storage, the way of storing data and its maintenance are safely hidden from the users. The database management services allow not only a single user, but it can be accessed by multiple users at the same time. This feature of multiple usages is allowed by almost every database management service provider.

A database management does not involve the problem of data redundancy or inconsistency. Its design is such that it provides the security mechanism to prevent unwanted users from accessing certain parts or whole of the database. For example, tellers in a bank see only that part of database that has information on customer accounts. They cannot access information about salaries of employees. It has many advantages over the file processing system, which stores the permanent records in various files. In this system the problem of redundancy prevails, as files and application programs are created by different programmers over a long period of time.

Besides keeping a tight control over data redundancy, efficient database management services also ensure the following:
* Enforce user defined rules to ensure the integrity of data in table form.

* Has a centralized data dictionary for the storage of information pertaining to data fields and data manipulation.

* Database management ensures that data can be shared across all applications. It enforces data access authorization.

* Database management service has an automatic, intelligent backup and recovery procedure of data.

A database management service also has its share of overheads. To begin with, its initial cost is very high, as it requires setting up of hardware, software and training, as well as, provision of security, concurrency control, and recovery and integrity functions.

Further on the down side, Database management service provides a generalized approach for defining and processing data. On the other hand, file processing system provides well defined database and applications that are simple and are not expected to change.