Chapter 8 : Accessing Organizational Information - Data Warehouse

History of Data Warehousing

• Data warehouses extend the transformation of data into information.
• In the 1990’s executives became less concerned with the day-to-day business operations and more concerned with overall business functions.
• The data warehouse provided the ability to support decision making without disrupting the day-to-day operations.

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.
• The primary purpose of a data warehouse is to aggregate information throughout an organization into a single repository for decision-making purposes.
• 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.
• Data mart – contains a subset of data warehouse information.

Multidimensional Analysis and Data Mining

• Databases contain information in a series of two-dimensional tables.
• In a data warehouse and data mart, information is multidimensional, it contains layers of columns and rows.
• Dimension – a particular attribute of information.
• Cube – common term for the representation of multidimensional information.

• Data mining – the process of analysing data to extract information not offered by the raw data alone.
• 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 and infers rules that predict future behaviour and guide decision making.

Information Cleansing or Scrubbing

• An organization must maintain high-quality data in the data warehouse.
• Information cleansing or scrubbing – a process that weeds out and fixes or discards inconsistent, incorrect, or incomplete information.
• Contact information in an operational system :

• Standardizing Customer name from Operational Systems :

• Information cleansing activities :

• Accurate and complete information :

Business Intelligence

• Business intelligence – information that people use to support their decision-making efforts.
• Principle BI enablers include :

1. Technology
2. People
3. Culture