Decision support systems assist the user in making important business decisions
by providing a specific result based on a business question.
Here are a few examples of business questions
that might be answered by a decision support system:
* Who are the top salespeople in each district;
what are their best-selling products?
* What time of year does each product sell best?
* What was the result of lowering the price of an item?
* What is the average commission for salespeople by district?
Decision support systems are different from OLTP
in that the user of a decision support system expects the result of a complex query
to take a significant amount of time to be returned.
Decision support queries can take anywhere from seconds to minutes to hours to complete.
This does not mean that response time is not important,
but some compromises can be made between throughput (performance for all users)
and response time (performance for each user).
Source:
Microsoft SQL Server 2000 Administrator's Companion eBook