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Principles of Database Design, P. I. MBAA 609 R. Nakatsu. Support Strategies for Competitive Advantage. Support Business Decision Making. Support Business Processes and Operations. Major Roles of Information Systems. File-Processing Systems. Problems with File-Processing Systems.
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Principles ofDatabase Design,P. I MBAA 609 R. Nakatsu
Support Strategies for Competitive Advantage Support Business Decision Making Support Business Processes and Operations Major Roles of Information Systems
Problems with File-Processing Systems • Data are separated and isolated • Data are often duplicated • Incompatible data files • Program-Data Dependence
The Relational Model • Data is represented in two-dimensional tables • Each of the tables is a matrix consisting of a series of row/column intersections • Files are called tables or relations • Fields (i.e. columns) of the tables are called attributes • Records (i.e. rows) of the tables are called tuples (rarely used terminology) • Information in more than one table can be easily extracted and combined
What is a database? • A database is an integrated collection of logically related data elements. A database consolidates records previously stored in separate files. • A database can be viewed as the topmost element of a data hierarchy: • database (a set of related files) • file (a collection of related records) • record (a group of logically related fields) • field (an attribute) • character (single alphabet, number, or other symbol)
Database Management System (DBMS) A DBMS (database management system) is a set of computer programs that is used to create, maintain, and provide controlled access to user databases What are some of the DBMS products on the marketplace today?
DBMS: Main Functions • Data definition • Define what data is stored, the type of data, how the data is related. • Specify how the data can be formatted and validated • Data manipulation • You can select which data you want, filter it, sort it, join it with other data, summarize it (querying data) • Data control • Allows you to specify security, as well as how the data can be shared. • Backup and recovery tools • Application Development • Graphical tools to develop menus, forms, and reports