Database Management Systems Chapter 1

Database
organized collection of logically related data.
Data
stored representations of meaningful objects and events
Structured Data
numbers, text, dates
Unstructured Data
images, video, documents
Information
data processed to increase knowledge in the person using the data.
Metadata
data that describes the properties and context of user data.
Disadvantages of File Processing
Program-Data Dependence
– All programs maintain metadata for each file they use

Duplication of Data
– Different systems/programs have separate copies of the same data

Limited Data Sharing
– No centralized control of data

Lengthy Development Times
– Programmers must design their own file formats

Excessive Program Maintenance
– 80% of information systems budget

The DATABASE Approach
– Central repository of shared data
– Data is managed by a controlling agent
– Stored in a standardized, convenient form
Database Management System (DBMS)
manages data resources like an operating system manages hardware resources.