CHAPTER 8 ( Accessing Organizational Information – Data Warehouse )

8.1  Describe the roles and purposes of data warehouses and data marts in an organization

8.2  Compare the multidimensional nature of data warehouses (and data marts) with the two-dimensional nature of databases

8.3  Identify the importance of ensuring the cleanliness of information throughout an organization

8.4  Explain the relationship between business intelligence and a data warehouse

History of Data Warehousing

v In the 1990’s executives became less concerned with the day-to-day business operations and more concerned with overall business functions

v The data warehouse provided the ability to support decision making without disrupting the day-to-day operations, because:

§Operational information is mainly current – does not include the history for better decision making

§Issue of quality information

§Without information history, it is difficult to tell how and why things change over time

v Data warehouse – a logical collection of information – gathered from many different operational databases – that supports business analysis activities and decision-making tasks

v The primary purpose of a data warehouse is to combined information throughout an organization into a single repository for decision-making purposes – data warehouse support only analytical processing

v Extraction, transformation, and loading (ETL) – a process that extracts information from internal and external databases, transforms the information using a common set of enterprise definitions, and loads the information into a data warehouse

v Data warehouse  then send subsets of the information to data mart

v Data mart – contains a subset of data warehouse information

Multidimensional Analysis
and Data Mining 

v Data mining – the process of analyzing data to extract information not offered by the raw data alone. Also known as "knowledge discovery" – computer-assisted tools and techniques for sifting through and analyzing vast data stores in order to find trends, patterns, and correlations that can guide decision making and increase understanding.

v To perform data mining users need data-mining tools

§Data-mining tool – uses a variety of techniques to find patterns and relationships in large volumes of information.

Eg: retailers can use knowledge of these patterns to improve the placement of items in the layout of a mail-order catalog page or Web page

Information Cleansing or Scrubbing 

v An organization must maintain high-quality data in the data warehouse

v Information cleansing or scrubbing – a process that weeds out and fixes or discards inconsistent, incorrect, or incomplete information

v Occur during ETL process and second on the information once if is in the data warehouse

Business Intelligence

v Business intelligence – refers to applications and technologies that are used to gather, provide access, analyze data, and information to support decision making effort.

v these systems will illustrate business intelligence in the areas of customer profiling, customer support, market research, market segmentation, product profitability, statistical analysis, and inventory and distribution analysis to name a few

CHAPTER 7 ( Storing Organizational Information )

7.1  Define the fundamental concepts of the relational database model

7.2  Evaluate the advantages of the relational database model

7.3    Compare relational integrity constraints and business-critical integrity constraints

7.4  Describe the benefits of a data driven Web site

7.5    Describe the two primary methods for integrating information across multiple databases

Relational Database Fundamentals

v Information is everywhere in an organization

v Information is stored in databases

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

v Database models include:

§Hierarchical database model – information is organized into a tree-like structure (using parent/child relationships) in such a way that it cannot have too many relationships

§Network database model – a flexible way of representing objects and their relationships

§Relational database model – stores information in the form of logically related two-dimensional tables

v Entity – a person, place, thing, transaction, or event about which information is stored

v Primary keys and foreign keys identify the various entity classes (tables) in the database

§ Primary key – a field (or group of fields) that uniquely identifies a given entity in a table

§ Foreign key – a primary key of one table that appears an attribute in another table and acts to provide a logical relationship among the two tables

Relational Database Advantages

v Database advantages from a business perspective include\

§Increased flexibility

§Increased scalability and performance

§Reduced information redundancy

§Increased information integrity (quality)

§Increased information security

Increased Flexibility

v A well-designed database should:\§Handle changes quickly and easily

§Provide users with different views

§Have only one physical view

•Physical view – deals with the physical storage of information on a storage device

§Have multiple logical views

•Logical view – focuses on how users logically access information

Increased Scalability and Performance

v A database must scale to meet increased demand,  while maintaining acceptable performance levels

§ Scalability – refers to how well a system can adapt to increased demands

§ Performance – measures how quickly a system performs a certain process or transaction

Reduced Information Redundancy

v Databases reduce information redundancy

§ Redundancy – the duplication of information or storing the same information in multiple places

v Inconsistency is one of the primary problems with redundant information

Increase Information Integrity (Quality)

v Information integrity – measures the quality of information

v Integrity constraint – rules that help ensure the quality of information

§Relational integrity constraint

§Business-critical integrity constraint

Increased Information Security

v Information is an organizational asset and must be protected

v Databases offer several security features including:

§Password – provides authentication of the user

§Access level – determines who has access to the different types of information

§Access control – determines types of user access, such as read-only access

Data-Driven Web Site Business Advantages

v Development

v Content Management

v Future Expandability

v Minimizing Human Error

v Cutting Production and Update Costs

v More Efficient

v Improved Stability

Integrating Information
among Multiple Databases

v Integration – allows separate systems to communicate directly with each other

§Forward integration – takes information entered into a given system and sends it automatically to all downstream systems and processes

§Backward integration – takes information entered into a given system and sends it automatically to all upstream systems and processes