Encyclopedia of Computer Science and Technology

132 database management systemMicrosoft Access is a popular relational database program for personal computers. It can be used for both simple (“flat file”) databases andfor complex databases with many interrelated files.and Oracle is prominent in the UNIX world. Beginningin the 1980s, SQL (Structured Query Language) became awidely used standard for querying and manipulating datatables, and most DBMS implement SQL (see sql).TrendsThe embracing of object-oriented programming principlesstarting in the 1980s has led to development of object-orienteddatabase structures (see object-oriented programming).In this approach tables, queries, views, and othercomponents of the DBMS are treated as objects that presenttheir functionality through interfaces (much in the way aclass in an object-oriented program does). This approachcan improve data integrity, flexibility (such as through theability to define new operations), and the development ofnew capabilities derived from predecessor objects. Objectmodels are also helpful in dealing with a networked worldin which data tables are often stored on separate computers.As important as changes in the architecture of databaseshave been, the impact of a changing environment has probablybeen even more significant. In particular, Web sites ofall kinds are increasingly being driven by databases (such asfor inventory and order processing for e-commerce). In turn,many databases of all sizes and types are now accessible andsearchable via the Web. This has meant a new emphasis onrapid development of database programs, particularly usingscripting languages, as well as fast and efficient Web-baseddatabase processing (see also Ajax). While the traditionalhigh-end corporate database systems such as Oracle andSQL Server are still vital for the enterprise, open-sourcealternatives (particularly MySQL) are in widespread use formany applications including wikis and content-managementsystems. The use of flexibly structured data (see xml andsemantic Web) to link and transform databases has alsoexpanded database concepts in the Web-centric world.Further ReadingAllen, Christopher, Catherine Creary, and Simon Chatwin. Introductionto Relational Databases. Berkeley, Calif.: McGraw-HillOsborne, 2003.