DRAFT

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Introduction
Many people think of a Data Warehouse as a recent Computer technology or systems construct, when in actuality the first data warehouses date back 20 years to the mid-1980’s.
In the beginning, a Data Warehouse was used, just as the name implies, for warehousing transactional and operational data to off-load the production systems each year. In a way it was where data went to die. That is until some savvy business analysts started to use the archive to do analytical reporting, year over year analysis, and use many other modeling technologies to understand where the company had been and what had affected its performance.


A Brief History of DW Time
Data Warehousing is often considered to be new technology, when in actuality it is over 20 years since the first warehouses were developed. In the early eighties, companies, driven by mainframe computers, went through an annual process of archiving last year’s operational data, to clear room (high-priced disk space) for the coming year. Usually, this data was archived to magnetic tape and if special reporting needs arose for historic data, this year’s data was rolled out to tape, last year’s data was rolled back in, the reporting operation was completed and the data sets were swapped back to where they originated. [See Slide 1.]
Cardinal


What is a Data Warehouse?
A Data Warehouse is a computer construct used to manipulate data in dimensional models for on-line analytical processing (OLAP) and reporting and for other applications such as support of Balanced Score Card and Master Data Management. The Data Warehouse process consists of six steps. [See Slide 6 as illustration for the following sections.]
Step