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