Unquestionably, the miner needs the detailed data in order to do analysis. But the summary data is useful at the outset of analysis, when the miner is planning an approach and needs to quickly look over the entire collection of detailed data. When there is a representative sample of different types of summary data, the miner can quickly survey what is and what is not in the warehouse. The summary data can save the miner fruitless iterations of analysis. One of the obvious trends is the need for the management of the warehouse environment.
Data wareh ouses and data marts tend to grow at an amazing rate.
As they grow, the volume of data that finds its way into the data warehouse becomes an obstacle to success. With this growth comes a slowdown in performance and an increase in budget. Soon the organization comes to the realization that the data warehouse infrastructure needs to be managed. One of those peculiarities is that of dormant data that creeps into the warehouse. Dormant data is data that is never used.