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Essentials of Management Information Systems Chapter 7 Managing Data Resources

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Managing Data Resources

Chapter 7



• United Asset Coverage (UAC) is a provider of maintenance services for office equipment

• Problem: data used by sales, marketing, customer service, and accounting department were scattered in several isolated information systems

• Solution: E-business suite to organize data based on an enterprise-wide relational database

Case Study



Objectives

1. Why do businesses have trouble finding the information they need in their information systems?

2. How does a database management system help businesses improve the organization of their information?



Objectives

3. How do the principal types of database models affect the way businesses can access and use information?

4. What are the managerial and organizational requirements of a database environment?

5. What new tools and technologies can make databases more accessible and useful?



Management Challenges

1. Organizational obstacles to a database environment

2. Cost/benefit considerations



• Bit: Smallest unit of data; binary digit (0,1)

• Byte: Group of bits that represents a single character

• Field: Group of words or complete number

• Record: Group of related fields

• File: Group of records of the same type

Organizing Data in a Traditional File Environment

File Organization Terms and Concepts



• Database: Group of related files

• Entity: Person, place, thing, or event about which information must be kept

• Attribute: A piece of information describing a particular entity

• Key field: Field that uniquely identifies every record in a file


File Organization Terms and Concepts




The data hierarchy

Figure 7-1




Entities and attributes

Figure 7-2



• Data redundancy

• Program-data dependence

• Lack of flexibility

• Poor security

• Lack of data-sharing and availability


Problems with the Traditional File Environment




Traditional file processing

Figure 7-3



Database

• Collection of centralized data

• Controls redundant data

• Data stored so as to appear to users in one location

• Services multiple application

The Database Approach to Data Management

Database Management Systems




The contemporary database environment

Figure 7-4



Database Management System (DBMS)

• Creates and maintains databases

• Eliminates requirement for data definition statements

• Acts as interface between application programs and physical data files

• Separates logical and physical views of data





Three Components to a DBMS

1. Data definition language: Formal language programmers use to specify structure of database

2. Data manipulation language: For extracting data from database, e.g. SQL

3. Data dictionary: Tool for storing, organizing definitions of data elements and data characteristics






Sample data dictionary report

Figure 7-5



How a DBMS Solves Problems of a Traditional File Environment

• Reduces data redundancy • Eliminates data inconsistency • Uncouples programs from data • Increases access and availability of data • Allows central management of data, data use, and

security





Relational DBMS

• Represents data as two-dimensional tables called relations

• Relates data across tables based on common data element

• Examples: DB2, Oracle, MS SQL Server


Types of Databases




The relational data model

Figure 7-6



Three Basic Operations in a Relational Database

• Select: Creates subset of rows that meet specific criteria

• Join: Combines relational tables to provide users with information

• Project: Enables users to create new tables containing only relevant information


Types of Databases




The three basic operations of a relational DBMS

Figure 7-7



Hierarchical DBMS

• Older system presenting data in tree-like structure

• Models one-to-many parent-child relationships

• Found in large legacy systems requiring intensive high-volume transactions: Banks; insurance companies

• Examples: IBMs IMS


Types of Databases




A hierarchical database for a human resources system

Figure 7-8



Network DBMS

• Older logical database model

• Models many-to-many parent-child relationships

• Example: Student – course relationship: Each student has many courses; each course has many students


Types of Databases




The network data model

Figure 7-9



Disadvantages of Hierarchical and Network DBMS

• Outdated

• Less flexible compared to RDBMS

• Lack support for ad-hoc and English language-like queries


Types of Databases



Object-Oriented Databases (OODBMS)

• Stores data and procedures as objects

• Better able to handle graphics and recursive data

• Data models more flexible

• Slower than RDBMS

• Hybrid: object-relational DBMS


Types of Databases



Two Design Exercises in Creating Database

• Conceptual (logical) design: Abstract model of database from business perspective

• Physical design: How the database is actually arranged on direct access storage devices

Creating a Database Environment

Designing Databases



Conceptual Database Design

• Identifies relationships between data elements • Identifies most efficient way to group data

elements • Identifies redundant data elements • Identifies grouping of data elements needed for

specific applications


Designing Databases



Entity-Relationship Diagram A methodology for documenting databases that

illustrates the relationship between various elements in the database

Normalization The process of creating small, stable, and adaptive

relations (tables) from complex groups of data when designing a relational database


Designing Databases




An entity-relationship diagram

Figure 7-10




An unnormalized relation for ORDER

Figure 7-11




A normalized relation for ORDER

Figure 7-12



Distributed Database

• Partitioned or replicated to more than one location • Increases service and responsiveness • Reduces vulnerability of single, massive central site • Depend on telecommunication lines • Pose security risks through distribution of sensitive data • Central data must be updated or justified with local data


Distributing Databases




Distributed databases

Figure 7-13




Key organizational elements in the database environment

Figure 7-14



Data Administration

• Develop information policy • Define information requirements • Plan for data • Oversee logical database design and database

dictionary development • Monitor use of information


Management Requirements for Database Systems



Data Planning and Modeling Methodology

• Enterprise-wide planning for data • Identify key entities, attributes, and relationships

that constitute the organization’s data


Management Requirements for Database Systems



Online Analytical Processing (OLAP)

• Multidimensional data analysis • Enables users to view the same data in different

ways using multiple dimensions • Each aspect of information – product, price,

region – represents a different dimension

Database Trends

Multidimensional Data Analysis



Database Trends

Multidimensional data model

Figure 7-15



• Data warehouse: Stores current and historical data for reporting, analysis

• Data mart: Subset of data warehouse with summary of data for specific users

• Datamining: Techniques to find hidden patterns, relationships in large pools of data to infer rules for predicting future trends

Database Trends

Data Warehouses and Datamining



Database Trends

Components of a data warehouse

Figure 7-16



Benefits of Data Warehouses

• Improved information and accessibility

• Ability to model and remodel data

• Enable access to data without affecting performance of underlying operational legacy systems

Database Trends




Data Reveal New Sales Opportunities

• How did the use of data warehouses and datamining help management at these companies make better decisions?

• What value do these systems provide?

Database Trends

Window on Management



Hypermedia database

• Organizes data as network of nodes

• Links nodes in pattern specified by user

• Supports text, graphic, sound, video and executable programs

Database Trends




Database Trends

A hypermedia database

Figure 7-17



Linking Internal Databases to the Web

• Database server: – Hosts DBMS – Receives SQL requests – Provides required data

• Middleware: – Works between Web server and DBMS to take requests – Handles connectivity to database – Can be application server in PHP or CGI scripts

Database Trends

Databases and the Web



Database Trends

Linking internal databases to the Web

Figure 7-18



Advantages to Web Access to Databases

• Browser software easy to use; little training

• Web interface requires no changes to internal database

• Costs less than custom interfaces

Database Trends

Databases and the Web



Contemporary Hardware Trends • Cloud Computing:

• A model of computing in which firms and individuals obtain computing resources over the Internet • Cloud infrastructure as a service • Cloud platform as a service • Cloud software as a service

• Public vs. private clouds • Utility computing, on-demand computing • Data storage security is in hands of provider

Databases in the Cloud



Cloud Computing Platform

In cloud computing, hardware and software capabilities are provided as services over the Internet. Businesses and employees have access to applications and IT infrastructure anywhere at any time using an Internet-connected device.




• Cloud computing providers offer database management services, but typically with less functionality

• By moving to a cloud solution, companies are able to scale their computing resources in response to real-time demand while keeping costs low


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Managing Data Resources - KU · PDF file• Problem: data used by sales ... and accounting department were scattered in several isolated information systems ... Chapter 7 Managing