1. Management Information Systems, Sixth Edition
Chapter 7:
Databases and Data Warehouses

2. Objectives
Explain the difference between traditional file organization 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
Management Information Systems, Sixth Edition

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
Management Information Systems, Sixth Edition

4. Managing Digital Data
Businesses collect and dissect data for many purposes
Data can be stored in database format
Easy access and manipulation
Databases have had a profound impact on business
An information industry has been created
Database technology integrated with the Internet has contributed to commerce significantly
Management Information Systems, Sixth Edition

5. The Traditional File Approach
Traditional file approach: no mechanism for tagging, retrieving, or manipulating data
Database approach: provides powerful mechanism for managing and manipulating data
Traditional approach is inconvenient:
Program-data dependency
High data redundancy
Low data integrity
Data redundancy: duplication of data
Data integrity: accuracy of data
Management Information Systems, Sixth Edition

6. The Traditional File Approach (continued)
Management Information Systems, Sixth Edition

7. The Database Approach Database approach: data organized as entities
Entity: an object about which an organization chooses to collect data, such as:
People
Events
Products
Character: smallest piece of data
A single letter or a digit
Field: single piece of information about entity
Management Information Systems, Sixth Edition

8. The Database Approach (continued)
Record: collection of related fields
File: collection of related records
Database fields can hold images, sounds, video clips, etc.
Field name allows easy access to the data
Database management system (DBMS): program used to:
Build databases
Populate a database with data
Manipulate data in a database
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11. The Database Approach (continued)
Query: a message to the database requesting data from specific records and/or fields
Database must be properly secured
Not everyone should have access to all data
Users will have different views of the database, based on the data they are allowed to see
Management Information Systems, Sixth Edition

12. The Database Approach (continued)
Database administrator (DBA): the person responsible for managing the database
Sets user limits for access to data in the database
DBMS is usually bundled with a programming language
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15. Database Models Database model: general logical structure
How records stored in the database
How relationships between records are established
Database models differ in:
How records are linked to each other
How users can navigate the database, retrieve records, and create records
Management Information Systems, Sixth Edition

16. The Relational Model Relational Model: consists of tables
Based on relational algebra
Tuple: record (or row)
Attribute: field (or column)
Relation: table of records
To design a relational database, you must understand the entities to be stored in the database and how they relate
Tables are independent of each other, but can be related to each other
Management Information Systems, Sixth Edition

17. The Relational Model (continued)
Key: a field whose values identify records
Used to retrieve records
Primary key: a field by which records are uniquely identified
Each record in the table must have a unique key value
Composite key: combination of fields that serve as a primary key
Management Information Systems, Sixth Edition

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19. The Relational Model (continued)
Management Information Systems, Sixth Edition

20. The Relational Model (continued)
Foreign key: a field that is common to two tables
Used to link the tables
This field is a primary key in one table and a foreign key in the other
Join table: composite of tables
Two types of table relationships:
One-to-many relationship: one item in a table is linked to many items in the other table
Many-to-many relationship: many items in a table are linked to many items of the other table
Management Information Systems, Sixth Edition

21. The Object-Oriented Model
Object-oriented database model: uses object-oriented approach for the database structure
Encapsulation: combined storage of data and relevant procedures to process it
Allows object to be “planted” in different data sets
Inheritance: the ability to create a new object by replicating the characteristics of an existing (parent) object
Object-oriented databases (ODBs) store data objects, not records
Management Information Systems, Sixth Edition

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23. Relational Operations
Relational operation: creates a temporary subset of a table or tables
Used to create a limited list or a joined table list
Three important relational operations:
Select: a selection of records based on conditions
Project: a selection of certain columns from a table
Join: join data from multiple tables to create a temporary table
Management Information Systems, Sixth Edition

24. Structured Query Language
Structured Query Language (SQL): query language of choice for DBMSs
Advantages of SQL:
It is an international standard
It is provided with most relational DBMSs
It has easy-to-remember, intuitive commands
Management Information Systems, Sixth Edition

25. The Schema and Metadata
Schema: a plan that describes the structure of the database, including:
Names and sizes of fields
Identification of primary keys
Relationships
Data dictionary: a repository of information about the data and its organization
Also called metadata: the data about the data
Management Information Systems, Sixth Edition

26. The Schema and Metadata (continued)
Metadata includes:
Source of the data
Tables related to the data
Field and index information
Programs and processes that use the data
Population rules: what is inserted, or updated, and how often
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28. Data Modeling
Databases must be carefully planned and designed to meet business goals
Data modeling: analysis of an organization’s data and identification of the data relationships
A proactive process
Develops a conceptual blueprint of the database
Entity relationship diagram: a graphical representation of all entity relationships
Management Information Systems, Sixth Edition

29. Data Modeling (continued)
Entity relationship diagram is composed of:
Boxes: identify entities
Lines: indicate relationship between entities
Crossbars: indicate mandatory fields
Circles: indicate optional
Crow’s feet: identify “many”
Management Information Systems, Sixth Edition

30. Data Modeling (continued)
Management Information Systems, Sixth Edition

31. Data Modeling (continued)
Management Information Systems, Sixth Edition

32. Databases on the Web Web is dependent on databases
Organizations must link their databases to the Web
Interface between Web and database required
Interface may be programmed in one of several Web programming languages, including:
Java servlets
Active server pages (ASP)
PHP (Hypertext Preprocessor)
Web application program interfaces (APIs)
Management Information Systems, Sixth Edition

33. Databases on the Web (continued)
Management Information Systems, Sixth Edition

34. Data Warehousing Most data collections are used for transactions
Accumulation of transaction data is useful
Data warehouse: a large repository database that supports management decision making
Typically relational
Data is collected from transactional databases
Data mart: a smaller collection of data focusing on a particular subject or department
Management Information Systems, Sixth Edition

35. From Database to Data Warehouse
Transactional databases are not suitable for business analysis
Contain only current, not historical data
Data warehouse requires large storage capacity:
Mainframe computers are often used
Scalability is an issue
Data warehouses grow continually
Management Information Systems, Sixth Edition

36. Phases in Data Warehousing
Three phases in transferring data from a transactional database to a data warehouse:
Extraction phase: create files from transactional database
Transformation phase: cleanse and modify the data format
Loading phase: transfer files to data warehouse
A properly built data warehouse becomes a single source for all data required for analysis
Data mining and online analytical processing (OLAP) use data in data warehouses
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38. Summary Organizations collect vast amounts of data
Database approach has several advantages over traditional file approach
Character: smallest piece of data
Field: made up of multiple characters
Record: collection of related fields
File: collection of related records
Database management system (DBMS): tool to construct databases
Management Information Systems, Sixth Edition

39. Summary (continued)
Relational and object-oriented database models have different advantages
Keys are used to form links among entities
Primary keys are unique identifiers
Object-oriented database maintains objects that contain data and procedures that process it
Structured Query Language (SQL) is an international standard for querying databases
Database designer must construct a schema to construct a database
Management Information Systems, Sixth Edition

40. Summary (continued)
Database designers conduct data modeling and create entity relationship diagrams to plan databases
Many databases are linked to Web
Data warehouses contain huge collections of historical transaction data
Data warehouse requires data extraction, transformation, and loading of transactional data
Invasion of privacy is exacerbated by database technology
Management Information Systems, Sixth Edition