Large data warehouse applications are beginning to become more necessary as large amounts of data are collected from the day to day interactions of businesses and their customers. Businesses are now using these enormous amounts of data to decide how and where to advertise, what resources projects will require in the future, and to gauge the general direction of the company to keep it on track. This paper is a case study of the design and implementation of a 1+ terabyte data warehouse for marketing decision support from a systems design and administration perspective. It will include a brief discussion of software selection and a detailed look at the sizing, testing, tuning, and implementation of the data warehouse. The case study will address such issues as sizing, I/O subsystems, I/O bandwidth, backup issues, performance trade-offs, and day to day operations.