Managing Data Resources Chapter 7

Data hierarchy Bit Byte Field Record File Database – a group of related files

Basic data concepts An entity is a person, place, thing or event on which we maintain information, for example, a student record An attribute is a field describing a characteristic or quality of an entity, for example, student name A key field is an identifier field

Traditional File Environment Manually create several different data management programs As compared with modern database management systems, traditional file environment has many problems.

Problems with the traditional file environment Data redundancy and confusion Program-data dependence Lack of flexibility Poor security Lack of data-sharing and availability

The database environment Avoid problems happened in the traditional file environment A single database serves multiple applications and also easily allow users to draw together all the information for other applications The database management system acts as the interface between the application programs and the data But is much more expensive and need professional management Can rent it through application software providers (ASP)

Components of a DBMS A data definition language A data manipulation language A data dictionary

A data definition language Is used to specify the content and structure of the database Define each data element

A data manipulation language Is used to manipulate data in the database for some application through some application software Structured query language, or SQL, is a famous data manipulation language

Data dictionary An automated or manual file that stores definition of data elements and data characteristics such as usage, physical representation, ownership, authorization and security

Database trends OLAP vs. OLTP – On line transaction processing does not analyze data using multidimensional data analysis called on line analytical processing Data warehouses are databases that store current and historical data of potential interest to managers throughout the company

Benefits of data warehouses Improved information Easy access The ability to model and remodel the data in the warehouse Uses OLAP and datamining to help refocus businesses

Linking internal DB to the web Legacy system Middle ware SQL Application server customer program Internet Web browser

Key organizational elements in the database environment Data administration Data planning and modeling methodology Database technology and management users

Data administration Data as an organizational resource Administration means to develop information policy, to plan for data including overseeing database design and monitoring how information system specialists and end-users use data The head of it is called CIO

Database administration Define and organize database structure and content Develop security procedures to safeguard the database Develop database documentation Maintains the database management software