Database management system

Database management system

 

All database management systems consist of a number of components that together allow the data they store to be accessed simultaneously by many users while maintaining its integrity. A characteristic of all databases is that the structure of the data they contain is defined and stored separately from  data itself in database schema.
Database management systems emerged to address the problem of storing and retrieving large amounts of data accurately and quickly. One of the earliest such systems was IBM Information Management System. which is still widely deployed more than 40 years later. IMS stores data hierarchically. The first commercially available relational database management system was available from Oracle in 1980.

The extensible markup language has become a popular format for data representation in recent years. Although XML data can be stored in normal file systems, it is commonly held in relational databases to take advantage of robust implementation verified by both theoretical and practical effort As an evolution of the Standard Generalized Markup Language (SGML), XML's text based structure offers advantage of being both machine and human readable.