Fundamentals & Ethics of Information Systems IS 201 Chapter 4 Organizing Data and Information Databases and Database Management Systems Chapter 4 – Organizing Data and Information Slide 1

Chapter 4 – Organizing Data and Information Slide 2 Learning Objectives Define general data management concepts and terms Highlight the advantages of the database approach to data management Describe the relational database model and outline its basic features Identify the common functions performed by all database management systems and identify popular user database management systems Identify and briefly discuss current database applications Chapter 4 – Organizing Data and Information Slide 2

Chapter 4 – Organizing Data and Information Slide 3 Chapter Overview Why Learn About Database Systems? What is a Database? The Hierarchy of Data The Database Approach Data Modeling Database Management Systems (DBMS) Data Warehouses, Data Marts, and Data Mining Business Intelligence Online Analytical Processing (OLAP) Object-Oriented Databases Summary Chapter 4 – Organizing Data and Information Slide 3

1. Why Learn About Database Systems? Database systems process and organize large amounts of data Database systems organize all transactions and services in our societies Examples Student registration database system Bank accounts database system Hospital patient record database system Chapter 4 – Organizing Data and Information Slide 4

Chapter 4 – Organizing Data and Information Slide 5 2. What is a Database? Database (DB): an organized collection of data Database Management System (DBMS): group of programs to: Manages and Manipulates database Provides an interface between database and user and other application programs Database administrator (DBA): skilled IS professional who directs all activities related to an organization’s database Chapter 4 – Organizing Data and Information Slide 5

Chapter 4 – Organizing Data and Information Slide 6 Data Management Without data and the ability to process it, an organization could not successfully complete most business activities Data consists of raw facts For data to be transformed into useful information, it must first be organized in a meaningful way Chapter 4 – Organizing Data and Information Slide 6

Chapter 4 – Organizing Data and Information Slide 7 3. The Hierarchy of Data Bit (a binary digit): a circuit that is either on or off Byte: eight bits Character: basic building block of information Each byte represents a character Can be an uppercase letter, lowercase letter, numeric digit, or special symbol Field: typically a name, number, or combination of characters that describes an aspect of a business object or activity Chapter 4 – Organizing Data and Information Slide 7

The Hierarchy of Data (cont.) Record: a collection of related data fields File: a collection of related records Database: a collection of integrated and related files Hierarchy of data: bits, characters, fields, records, files, and databases Chapter 4 – Organizing Data and Information Slide 8

The Hierarchy of Data (cont.) Chapter 4 – Organizing Data and Information Slide 9

Data Entities, Attributes, and Keys Entity: a generalized class of people, places, or things for which data is collected, stored, and maintained (students, teachers, employees, …) Attribute: characteristic of an entity Data item (value): value of an attribute Primary key: field or set of fields that uniquely identifies the record Chapter 4 – Organizing Data and Information Slide 10

Data Entities, Attributes, and Keys (cont.) Keys and Attributes Chapter 4 – Organizing Data and Information Slide 11

Chapter 4 – Organizing Data and Information Slide 12 4. The Database Approach Traditional approach to data management: separate data files are created for each application Results in data redundancy (duplication) Data redundancy conflicts with data integrity Database approach to data management: pool of related data is shared by multiple applications Significant advantages over traditional approach Chapter 4 – Organizing Data and Information Slide 12

The Database Approach to Data Management DB Approach The Database Approach to Data Management Chapter 4 – Organizing Data and Information Slide 13

Advantages of the Database Approach DB Approach (cont.) Advantages of the Database Approach Chapter 4 – Organizing Data and Information Slide 14

Advantages of the Database Approach (continued) DB Approach (cont.) Advantages of the Database Approach (continued) Chapter 4 – Organizing Data and Information Slide 15

Disadvantages of the Database Approach DB Approach (cont.) Disadvantages of the Database Approach Chapter 4 – Organizing Data and Information Slide 16

Chapter 4 – Organizing Data and Information Slide 17 5. Data Modeling Data model: a diagram of data entities and their relationships Entity-relationship (ER) diagrams: data models that use basic graphical symbols to show the organization of and relationships between data entities Chapter 4 – Organizing Data and Information Slide 17

An Entity-Relationship (ER) Diagram for a Customer Order Database Data Modeling (cont.) Entity Relationship An Entity-Relationship (ER) Diagram for a Customer Order Database Chapter 4 – Organizing Data and Information Slide 18

Chapter 4 – Organizing Data and Information Slide 19 Data Modeling (cont.) A Simplified ER Diagram Showing the Relationship Between the Manager, Department, and Project Tables Chapter 4 – Organizing Data and Information Slide 19

Chapter 4 – Organizing Data and Information Slide 20 DB Design Building a database requires two types of designs Logical design Abstract model of how data should be structured and arranged to meet an organization’s information needs Physical design Fine-tunes the logical database design for performance and cost considerations Chapter 4 – Organizing Data and Information Slide 20

Chapter 4 – Organizing Data and Information Slide 21 Building DB When building a database, consider: Content: What data should be collected, at what cost? Access: What data should be provided to which users and when? Logical structure: How should data be arranged to make sense to a given user? Physical organization: Where should data be physically located? Chapter 4 – Organizing Data and Information Slide 21

Chapter3 – Binary Number System Slide 22 Database Models Flat file Databases Plain text files usually contain one record per line Fields can be separated by delimiters such as comma or tab characters Relational Databases 2-D tables Each row represents a record Each column represents an attribute Object oriented Databases Chapter3 – Binary Number System Slide 22

The Relational Database Model Relational model: all data elements are placed in two-dimensional tables, which are the logical equivalent of files In the relational model Each table is an entity Each row of a table represents a record Columns of the table represent attributes Domain: the allowable values for data attributes Chapter 4 – Organizing Data and Information Slide 23

The Relational Database Model (cont.) A Relational Database Model Chapter 4 – Organizing Data and Information Slide 24

Chapter 4 – Organizing Data and Information Slide 25 Manipulating Data Selecting: eliminates rows according to criteria Projecting: eliminates columns in a table Joining: combines two or more tables Linking: relates or links two or more tables using common data attributes Chapter 4 – Organizing Data and Information Slide 25

Linking Data Tables to Answer an Inquiry Chapter 4 – Organizing Data and Information Slide 26

6. Database Management Systems (DBMS) DBMS: a group of programs used as an interface between a database and application programs or a database and the user Creating and implementing the right DBMS ensures that the database will support both business activities and goals user Application DBMS DB Chapter 4 – Organizing Data and Information Slide 27

Overview of Database Types Single user Only one person can use the database at a time Examples: Access, FileMaker, and InfoPath Multiple user Allows dozens or hundreds of people to access the same database system at the same time Examples: Oracle, Sybase, and IBM Chapter 4 – Organizing Data and Information Slide 28

Chapter 4 – Organizing Data and Information Slide 29 DB schema Schema: description of the entire database Large database systems typically use schemas to define the tables and other database features associated with a person or user Chapter 4 – Organizing Data and Information Slide 29

Chapter 4 – Organizing Data and Information Slide 30 Creating a DB schema Data Definition Language (DDL) Collection of instructions/commands that define and describe data and data relationships in a database Data dictionary: a detailed description of all the data used in the database Chapter 4 – Organizing Data and Information Slide 30

Using DDL to define schema Using a Data Definition Language to Define a Schema Chapter 4 – Organizing Data and Information Slide 31

A Typical Data Dictionary Entry Chapter 4 – Organizing Data and Information Slide 32

Storing and Retrieving Data When an application requests data from the DBMS, the application follows a logical access path When the DBMS goes to a storage device to retrieve the requested data, it follows a path to the physical location (physical access path) where the data is stored Chapter 4 – Organizing Data and Information Slide 33

Storing and Retrieving Data (cont.) Logical and Physical Access Paths Chapter 4 – Organizing Data and Information Slide 34

Manipulating Data and Generating Reports Query-By-Example (QBE): a visual approach to developing database queries or requests Data Manipulation Language (DML): commands that manipulate the data in a database Structured Query Language (SQL): ANSI standard query language for relational databases Database programs can produce reports, documents, and other outputs Chapter 4 – Organizing Data and Information Slide 35

Examples of SQL Commands Chapter 4 – Organizing Data and Information Slide 36

Database Administration Database administrator (DBA): directs or performs all activities to maintain a database environment Designing, implementing, and maintaining the database system and the DBMS Establishing policies and procedures Employee training Chapter 4 – Organizing Data and Information Slide 37

Chapter 4 – Organizing Data and Information Slide 38 Popular DBMS Popular DBMSs for end users: Microsoft Access and FileMaker Pro Entire market includes databases by IBM, Oracle, and Microsoft Examples of open-source database systems: PostgreSQL and MySQL Many traditional database programs are now available on open-source operating systems Chapter 4 – Organizing Data and Information Slide 38

Chapter 4 – Organizing Data and Information Slide 39 Selecting a DBMS Important characteristics of databases to consider Size of the database Cost of the system Number of concurrent users Performance Ability to be integrated with other systems Vendor considerations Chapter 4 – Organizing Data and Information Slide 39

Using DBMS with Other Software DBMS are often used with other software packages or the Internet A DBMS can act as a front-end application or a back-end application Front-end application: interacts with users Back-end application: interacts with applications Chapter 4 – Organizing Data and Information Slide 40

Linking Databases to the Internet Linking databases to the Internet is important for many organizations and people Allows people to access and manipulate a number of traditional databases at the same time through the Internet Chapter 4 – Organizing Data and Information Slide 41

7. Data Warehouses and Data Marts Data warehouse: collects business information from many sources in the enterprise Data mart: a subset of a data warehouse Chapter 4 – Organizing Data and Information Slide 42

J. Berri Chapter3 – Binary Number System Slide 43 Data mining Data mining: an information-analysis tool for discovering patterns and relationships in a data warehouse or a data mart J. Berri Chapter3 – Binary Number System Slide 43

Elements of data warehouse Elements of a Data Warehouse Chapter 4 – Organizing Data and Information Slide 44

8. Business Intelligence Business intelligence (BI): gathering the right information in a timely manner and usable form and analyzing it to have a positive impact on business and enterprise Turns data into useful information that is then distributed throughout an enterprise Chapter 4 – Organizing Data and Information Slide 45

Business Intelligence (cont.) Competitive intelligence: aspect of business intelligence limited to information about competitors and the ways that knowledge affects strategy, tactics, and operations Counterintelligence: steps an organization takes to protect information sought by “hostile” intelligence gatherers Chapter 4 – Organizing Data and Information Slide 46

9. Online Analytical Processing (OLAP) Software that allows users to explore data from a number of different perspectives Comparison of OLAP and Data Mining Chapter 4 – Organizing Data and Information Slide 47

10. Object-Oriented Databases Stores both data and its processing instructions Method: a procedure or action Message: a request to execute or run a method Chapter 4 – Organizing Data and Information Slide 48

Chapter 4 – Organizing Data and Information Slide 49 11. Summary Hierarchy of data: bits, characters, fields, records, files, and databases Entity: generalized class of people, places, or things for which data is collected, stored, and maintained Attribute: characteristic of an entity Data model: diagram of data entities and relationships Relational model: describes data in which all elements are placed in two-dimensional tables called relations Chapter 4 – Organizing Data and Information Slide 49

Chapter 4 – Organizing Data and Information Slide 50 Summary (cont.) A database management system (DBMS) is a group of programs used as an interface between: Database and application programs Database and the user Data warehouse: database that collects business information from all aspects of a company’s processes, products, and customers Data mining: an information-analysis tool for discovering patterns and relationships in a data warehouse Chapter 4 – Organizing Data and Information Slide 50