The document discusses databases and data warehouses. It explains the differences between traditional file organization and database management. Relational and object-oriented database models are used to construct and manipulate databases. Data modeling creates a conceptual design for databases. Data is extracted from transactional databases and transformed for loading into data warehouses to support analysis and decision making.

1. Management Information Systems
CSC-373
Databases and Data Warehouses

2. Objectives
• Explain the difference between traditional file
organisation and the database approach to managing
digital data
• Explain how relational and object oriented database
management systems are used to construct databases,
populate them with data, and manipulate the data to
produce information
• Enumerate the most important features and operations of
a relational database, the most popular database model

3. Objectives (continued)
• Understand how data modeling and design creates a conceptual
blueprint of a database
• Discuss how databases are used on the Web
• List the operations involved in transferring data from transactional
databases to data warehouses

4. Managing Digital Data
• Businesses collect and dissect data (analyze data in minute detail)
• Data can be stored in powerful database format
• Easy access and manipulation
• Databases have profound impact on business
• Database technology integrated with Internet

5. The Traditional File Approach
• Traditional file approach: no mechanism for manipulating data
• Database approach: has mechanism for manipulating data
• Traditional approach inconvenient
• Data redundancy:
• Presence of duplicate data in multiple files
• High data redundancy
• Low data integrity

6. • Problems with the traditional file environment (files
maintained separately by different departments)
–Data inconsistency:
• Same attribute has different values
–Data integrity: accuracy of data
–Program-data dependence:
• When changes in program requires changes to data accessed by program
–Lack of flexibility
–Poor security
–Lack of data sharing and availability
The Traditional File Approach (cont.(

7. The use of a traditional
approach to file processing
encourages each functional
area in a corporation to
develop specialized
applications. Each
application requires a
unique data file that is
likely to be a subset of the
master file. These subsets
of the master file lead to
data redundancy and
inconsistency, processing
inflexibility, and wasted
storage resources.
FIGURE 6-2
TRADITIONAL FILE PROCESSING

8. Traditional File Processing
Chapter 5 Data Resource
ManagementChapter 5
8

9. The Traditional File Approach (continued)

10. • Database
– Serves many applications by centralizing data and controlling redundant data
• Database management system (DBMS)
– Interfaces between applications and physical data files
– Separates logical and physical views of data
– Solves problems of traditional file environment
• Controls redundancy
• Eliminates inconsistency
• Uncouples programs and data
• Enables organization to central manage data and data security
Capabilities of Database Management Systems (DBMSs)

11. A single human resources database provides many different views of data, depending on the information
requirements of the user. Illustrated here are two possible views, one of interest to a benefits specialist and
one of interest to a member of the company’s payroll department.
FIGURE 6-3
HUMAN RESOURCES DATABASE WITH MULTIPLE VIEWS

12. The Database Approach
• Database approach: data organised as entities
• Entity: object that has data
• People
• Events
• Products
• Character: smallest piece of data
• Field: single piece of information about entity
• Record: collection of fields

13. The Database Approach (continued)
• File: collection of related records
• Database management system (DBMS): program used to build
databases
• Populates with data
• Manipulates data
• Query: message requesting access to data

14. The Database Approach (continued)
• Database has security issues
• Database administrator (DBA): limits user access to database
• Requires users to enter codes
• DBMS bundled with fourth-generation languages

15. The Database Approach (continued)

16. The Database Approach (continued)

17. The Database Approach (continued)

18. Database Models
• Database model: general logical structure
• How records stored in database
• Records linked differently in different models
• Models constantly changing

19. The Relational Model
• Relational Model: consists of tables
• Based on relational algebra
• Tuple: record
• Attribute: field
• Relation: table
• Key: identifier field
• Used to retrieve records

20. Relational Model (continued)

21. The Relational Model (continued)
• Primary key: unique key
• Uniquely identifies record
• Required in table
• Composite key: combination of fields
• Serves as primary key
• Foreign key: shared field
• Links tables
• Join table: composite of tables

22. The Relational Model (continued)

23. The Relational Model (continued)
• Table relationships with other tables
• One-to-many relationship: one item in table linked to
many items in other table
• Many-to-many relationship: many items in table
linked to many items of other table

24. The Object-Oriented Model
• Object-Oriented model: uses object-oriented approach
• Encapsulation: combined storage of data and relevant procedures
• Allows object to be planted in different data sets
• Inheritance: creates new object by replicating characteristics of existing
(parent) object

25. The Object-Oriented Model (continued)

26. Relational Operations
• Relational operation: create temporary subset of
table
• Create limited list or joined table list
• Select records based on conditions
• Project columns
• Join tables to create temporary table

27. Structured Query Language
• Structured query language: language of
choice for DBMSs
• Advantages
• Standardised language
• Used in many host languages
• Portable

28. The Schema and Metadata
• Schema: plan
• Describes structure of database
• Names and sizes of fields
• Identifies primary keys
• Data dictionary: repository of information about data

29. The Schema and Metadata (continued)
• Metadata: data about data
• Source of data
• Tables related to data
• Field information
• Usage of data
• Population rules

30. The Schema and Metadata (continued)

31. Data Modeling
• Databases must be carefully planned
• Data modeling: analysis and organisation of data
• Proactive process
• Develop conceptual blueprint
• Entity relationship diagram: graphical representation of relationships

32. Data Modeling (continued)
• Entity relationship diagram
• Boxes identify entities
• Lines indicate relationship
• Crossbars indicate mandatory fields
• Circles indicate optional
• Crows feet identify “many”

33. Data Modeling (continued)

34. Data Modeling (continued)

35. Databases on the Web
• Web dependent on databases
• Interface between Web and database required
• CGI
• ASP
• API

36. Databases on the Web (continued)

37. Data Warehousing
• Data collections used for transactions
• Accumulation of transaction data useful
• Data warehouse: large database
• Typically relational
• Supports decision making
• Data copied from transactional database
• Data mart: collection of data focusing on particular
subject

38. From Database to Data Warehouse
• Transactional database not suitable for business
analysis
• Only current data
• Not historic
• Data warehouse requires large storage capacity
• Mainframe computers used
• Scalability issue

39. Phases in Building a Data Warehouse
• Begin building data warehouse after equipment
secured
• Extraction phase
• Create files from transactional database
• Transformation phase
• Cleanse and modify data
• Loading phase
• Transfer files to data warehouse

40. Phases in Building a Data Warehouse
(continued)

41. Summary
• organisations collect vast amounts of data
• Database approach has advantages over traditional
approach
• Character: smallest piece of data
• File: collection of records
• Designer must construct schema to construct
database

42. Summary (continued)
• Database management system enables database
construction and manipulation
• Relational and object-oriented database models have
different advantages
• Keys used to form links among entities
• Object-oriented database maintains links differently
• SQL adopted as international standard

43. Summary (continued)
• Designers conduct data modeling to show required
tables
• Databases often linked to Web
• Data warehouses contain huge collections of historical
data
• Data warehouse allows data extraction,
transformation, and loading
• Invasion of privacy is exacerbated by database
technology

44. Bibliography
• Chapter 6: Databases and Data Warehouses,
Effy Oz “Management Information Systems”. (6th Edition).
Cencage Learning: www.cengage.co.uk/oz
• Kenneth. C. Laudon & Jane P. Laudon “Management Information Systems: Managing a Digital Firm”
(15th Edition) Pearson.
• James A. O’Brien. “Management Information Systems”
(11th Edition) McGraw Hill.