McGraw-Hill/Irwin ©2009 The McGraw-Hill Companies, All Rights Reserved CHAPTER 6 DATABASES AND DATA WAREHOUSES CHAPTER 6 DATABASES AND DATA WAREHOUSES Business Driven Information Systems 2e

McGraw-Hill/Irwin ©2009 The McGraw-Hill Companies, All Rights Reserved SECTION 6.1 DATABASE FUNDAMENTALS

6-3 Database Fundamentals Database – maintains information about various types of objects (inventory), events (transactions), people (employees), and places (warehouses)

6-4 The Value of Transactional and Analytical Information

6-5 The Value of Timely Information Timeliness is an aspect of information that depends on the situation –Real-time information – immediate, up-to- date information –Real-time system – provides real-time information in response to query requests

6-6 The Value of Quality Information Characteristics of high-quality information include: –Accuracy –Completeness –Consistency –Uniqueness –Timeliness

6-7 Understanding the Costs of Poor Information Potential business effects from low quality information: –Inability to accurately track customers –Difficulty identifying valuable customers –Inability to identify selling opportunities –Marketing to nonexistent customers –Difficulty tracking revenue –Inability to build strong customer relationships

6-8 Relational Database Fundamentals Relational database model – stores information in the form of logically related two-dimensional tables Other DB Models –Hierarchical database model –Network database model –Flat –Object oriented

6-9 Entities and Attributes Entity – a person, place, thing, transaction, or event about which information is stored Attribute (field, column) – characteristics or properties of an entity class

6-10 Hierarchy of Data

6-11 Keys and Relationships Primary keys and foreign keys identify the various entities in the database –Primary key – a field (or group of fields) that uniquely identifies a given record in a table –Foreign key – a primary key of one table that appears as an attribute in another table which provide a logical relationship among the two tables

6-12 Potential relational database for Coca- Cola

6-13 Database Concerns Scalability – refers to how well a system can adapt to increased demands Performance – measures how quickly a system performs a certain process or transaction

6-14 Database Advantages Databases reduce information redundancy –Redundancy – the duplication of information or storing the same information in multiple places Inconsistency is one of the primary problems with redundant information

6-15 Increase Information Integrity (Quality) Information integrity – measures the quality of information Integrity constraint – rules that help ensure the quality of information –Relational integrity constraint –Business-critical integrity constraint

6-16 Database Management Systems Database management systems (DBMS) – software through which users and application programs interact with a database

6-17 Integrating Information among Multiple Databases Building a central repository specifically for integrated information

McGraw-Hill/Irwin ©2009 The McGraw-Hill Companies, All Rights Reserved SECTION 6.2 DATA WAREHOUSE FUNDAMENTALS

6-19 DATA WAREHOUSE FUNDAMENTALS Data warehouse – a logical collection of information – gathered from many different operational databases – that supports business analysis activities and decision-making tasks Data mart – contains a subset of data warehouse information

6-20 DATA WAREHOUSE FUNDAMENTALS

6-21 Information Cleansing or Scrubbing Standardizing Customer name from Operational Systems

6-22 Information Cleansing or Scrubbing Accurate and complete information

6-23 Data Mining and Business Intelligence Data mining – the process of analyzing data to extract information not offered by the raw data alone To perform data mining users need data-mining tools Data-mining tools helps users uncover BI