1. Managing Data Resources
Chapter 7
Managing Data Resources

2. Objectives
Why do businesses have trouble finding the information they need in their information systems?
How does a database management system help businesses improve the organization of their information?

3. Objectives
How do the principal types of database models affect the way businesses can access and use information?
What are the managerial and organizational requirements of a database environment?
What new tools and technologies can make databases more accessible and useful?

4. Management Challenges
Organizational obstacles to a database environment
Cost/benefit considerations

5. Organizing Data in a Traditional File Environment
File Organization Terms and Concepts
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

6. 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

7. Organizing Data in a Traditional File Environment
The data hierarchy
Figure 7-1

8. Organizing Data in a Traditional File Environment
Entities and attributes
Figure 7-2

9. Organizing Data in a Traditional File Environment
Problems with the Traditional File Environment
Data redundancy
Program-data dependence
Lack of flexibility
Poor security
Lack of data-sharing and availability

10. Organizing Data in a Traditional File Environment
Traditional file processing
Figure 7-3

11. The Database Approach to Data Management
Database Management Systems
Database
Collection of centralized data
Controls redundant data
Data stored so as to appear to users in one location
Services multiple application

12. The Database Approach to Data Management
The contemporary database environment
Figure 7-4

13. The Database Approach to Data Management
Database Management Systems
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

14. The Database Approach to Data Management
Database Management Systems
Three Components to a DBMS
Data definition language: Formal language programmers use to specify structure of database
Data manipulation language: For extracting data from database, e.g. SQL
Data dictionary: Tool for storing, organizing definitions of data elements and data characteristics

15. The Database Approach to Data Management
Sample data dictionary report
Figure 7-5

16. The Database Approach to Data Management
Database Management Systems
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

17. The Database Approach to Data Management
Types of Databases
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

18. The Database Approach to Data Management
The relational data model
Figure 7-6

19. The Database Approach to Data Management
Types of Databases
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

20. The Database Approach to Data Management
The three basic operations of a relational DBMS
Figure 7-7

21. The Database Approach to Data Management
Types of Databases
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

22. The Database Approach to Data Management
A hierarchical database for a human resources system
Figure 7-8

23. The Database Approach to Data Management
Types of Databases
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

24. The Database Approach to Data Management
The network data model
Figure 7-9

25. The Database Approach to Data Management
Types of Databases
Disadvantages of Hierarchical and
Network DBMS
Outdated
Less flexible compared to RDBMS
Lack support for ad-hoc and English language-like queries

26. The Database Approach to Data Management
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

27. Creating a Database Environment
Designing 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

28. 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

29. Creating a Database Environment
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 data structures from complex groups of data when designing a relational database

30. Creating a Database Environment
An entity-relationship diagram
Figure 7-10

31. Creating a Database Environment
An unnormalized relation for ORDER
Figure 7-11

32. Creating a Database Environment
A normalized relation for ORDER
Figure 7-12

33. Creating a Database Environment
Distributing Databases
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

34. Creating a Database Environment
Distributed databases
Figure 7-13

35. Creating a Database Environment
Key organizational elements in the database environment
Figure 7-14

36. Creating a Database Environment
Management Requirements for Database Systems
Data Administration
Develop information policy
Define information requirements
Plan for data
Oversee logical database design and database dictionary development
Monitor use of information

37. Creating a Database Environment
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

38. Creating a Database Environment
Management Requirements for Database Systems
Database Technology, Management,
and Users
Databases require DBMS software and staff
Database design group defines and organizes structure and content of database
Database administration: establish physical database, logical relations, access rules

39. Multidimensional Data Analysis
Database Trends
Multidimensional Data Analysis
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

40. Multidimensional data model
Database Trends
Multidimensional data model
Figure 7-15

41. Data Warehouses and Datamining
Database Trends
Data Warehouses and Datamining
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

42. Components of a data warehouse
Database Trends
Components of a data warehouse
Figure 7-16

43. Data Warehouses and Datamining
Database Trends
Data Warehouses and Datamining
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

44. Data Reveal New Sales Opportunities
Database Trends
Window on Management
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?

45. Data Warehouses and Datamining
Database Trends
Data Warehouses and Datamining
Hypermedia database
Organizes data as network of nodes
Links nodes in pattern specified by user
Supports text, graphic, sound, video and executable programs

46. Database Trends
A hypermedia database
Figure 7-17

47. Linking Internal Databases to the Web
Database Trends
Databases and the Web
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 or CGI scripts

48. Linking internal databases to the Web
Database Trends
Linking internal databases to the Web
Figure 7-18

49. Advantages to Web Access to Databases
Database Trends
Databases and the Web
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

50. Web Access for Royal Bank Statements
Database Trends
Window on Technology
Web Access for Royal Bank Statements
Pays Off
What are the business benefits of providing a Web interface for the Bankbook Reconstruct application?
What value does this application provide the company and its customers?

51. Database Woes Plague Homeland Security and Law Enforcement
Chapter 7 Case Study
Database Woes Plague Homeland Security and Law Enforcement
Briefly summarize why it is important to connect much of the data in many of the federal, state, and local information systems.
Describe the major data management problems in bringing these data together.
Describe the management, organization, and technology issues that need to be addressed to make these data easily available to those who need it.

52. Database Woes Plague Homeland Security and Law Enforcement
Chapter 7 Case Study
Database Woes Plague Homeland Security and Law Enforcement
Suppose you are a consultant to the federal government. Based on what you have read in this chapter, suggest and describe three approaches you might recommend for making this massive amount of data easily and quickly available when needed.