Database management and design

The use of a central repository for data and a database management system that enables programs to share data more efficiently and ensures the consistency of the data across the system is discussed. Relational databases, which represent both entities and relationships using tables, are described. It is shown that by proper design of the relational tables, the redundancy and wasted space of many ad hoc databases can be eliminated. Data are retrieved from a relational database through the use of a procedural query language. The leading query language for relational databases, the Structured Query Language (SQL), is examined