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