In many ways, the data warehouse requires a simpler set of technological features than its operational predecessors. Online updating with the data warehouse is not needed, locking and integrity needs are minimal, only a very basic teleprocessing interface is required, and so forth. Nevertheless, there are a fair number of technological requirements for the data warehouse. This chapter outlines some of these.
Prior to data warehousing, the terms terabytes and petabytes were unknown; data capacity was measured in megabytes and gigabytes. After data warehousing, the whole perception changed. Suddenly, what was large one day was trifling the next. The explosion of data volume came about because the data warehouse required that both detail and history be mixed in the same environment. The issue of storing and managing large volumes of data is so important that it pervades all other aspects of data warehousing. With this in mind, the first and most important technological requirement for the data warehouse is the ability to manage large amounts of data, as shown in Figure 5-1. There are many approaches, and in a large warehouse environment, more than one approach will be used.
Figure 5.1. Some basic requirements for technology supporting a data warehouse.
Large amounts of data need to be managed in many ways — through ...