What is a Data
A data warehouse is a computer system
designed to give business decision makers instant access to
information. The warehouse copies its data from existing systems
like order entry, general ledger, human resources and stores it for
use by executives rather than programmers. Data warehouse users use
special software that allows them to create and access information
when they need it, as opposed to a reporting schedule defined by the
information systems (IS) department.
What are the business
benefits of data warehousing?
Immediate information delivery
Data warehouses shrink
the length of time it takes between when business events occurrence
and executive alert. For example, in many corporations, sales
reports are printed once a month - about a week after the end of
each month. Thus, the June sales reports are delivered during the
first week in July. Using a warehouse, those same reports are
available on a daily basis. Given this data delivery time
compression, business decision makers can exploit opportunities that
they would otherwise miss.
Data integration from across, and even outside, the
To provide a complete picture, warehouses
typically combine data from multiple sources such as a company's
order entry and warranty systems. Thus, with a warehouse, it may be
possible to track all interactions a company has with each customer
- from that customer's first inquiry, through the terms of their
purchase all the way through any warranty or service interactions.
This makes it possible for managers to have answers to questions
like, "Is there a correlation between where a customer buys our
product and the amount typically spent in supporting that customer?"
Future vision from historical trends
analysis frequently includes trend and seasonality analysis. To
support this, warehouses typically contain multiple years of
Tools for looking at data in new ways
Instead of paper
reports, warehouses give users tools for looking at data
differently. They also allow those users to manipulate their data.
There are times when a colour coded map speaks volumes over a simple
paper report. An interactive table that allows the user to drill
down into detail data with the click of a mouse can answer questions
that might take months to answer in a traditional system.
Freedom from IS department resource limitations
the problems with computer systems is that they usually require
computer experts to use them. When a report is needed, the
requesting manager calls the IS department. IS then assigns a
programmer to write a program to produce the report. The report can
be created in a few days or, in extreme cases, in over a year. With
a warehouse, users create most of their reports themselves. Thus, if
a manager needs a report for a meeting in half an hour, they, or
their assistant, can create that report in a matter of minutes.
What can we do with a
warehouse that we can't do today?
to warehouses to answer a limitless variety of questions and in
almost all fields. Data warehouse applications include: