Database Administration Database Management System

Database Administration database management system (DBMS) is a program that lets one or more computer users create and access data in a database (Database Management System, TechTarget). The DBMS manages requests from users and other programs in a way that they do not need to understand where the data is physically located and who else may also be accessing the data. In handling user requests, the DBMS ensures the security and integrity of the data.

The database security and authorization subsystem is responsible for ensuring the security of portions of a database against unauthorized access. There are two types of security mechanisms, discretionary and mandatory (Database Security and Administration, 2001). A discretionary security mechanism grants privileges to users, including the capability to access specific data files, records, or fields in a specified mode such as read, insert, delete, or update. A mandatory security mechanism enforces multilevel security by classifying the data and users into various security classes (or levels) and then implementing the appropriate security policy.

Access control prevents unauthorized persons from accessing the system itself to obtain information or make changes (Database Security and Administration, 2001). Access control is handled by creating user accounts and passwords to control the log-in process by the DBMS. Controlling the access to a statistical database, which is used to provide statistical information or summaries of values based on various criteria, is also required. Further, data encryption adds an important layer of protection. Any user trying to access the data needs the right password and the encryption key as well. One advantage of data encryption is that files can be unreadable to people who have access to the database, but no databases privileges.

Database application programs must usually be designed to be executed concurrently by many users. By grouping related database queries into transactions, DBMS systems can guarantee that each transaction satisfies the ACID properties: Atomicity, Consistency, Isolation, and Durability. However, if a database application is decomposed into transactions in an incorrect manner, the application may fail when executed concurrently.