Business information system Essay Example | Topics and Well Written Essays - 500 words

Business information system - Essay Example In this paper we will discuss different aspects of data warehouse. This section will explain four main characteristics of data warehouse. These characteristics give a more clear view of data warehouse. First characteristic of data warehouse is â€Å"Subject Oriented† (Kimball & Ralph 2002), It means data warehouse should be built for a specific subject or domain. It also means that Data that provides information about the concerning topic/ subject instead of organizations ongoing processes. Second characteristic is â€Å"integrated† nature of data warehouse. It Means data that is gathered from different sources are integrated into a single structure. Third characteristic is â€Å"Time-variant†: It means all data that is stored in the data warehouse is recognized with a specific time period. Forth and last characteristic is â€Å"Non-volatile† nature of data warehouse. Data is never deleted from data warehouse. But when it exceeds from a certain level, it is archived and stored at differ places (Kimball & Ralph 2002). There is a question about data warehouse: When data warehouse has data in terabits, then how it can handle such amount of data? The answer is: data warehouse uses parallelism approach to handle such amount of data. By this approach data is divided into small parts and parallel unit of data warehouse store retrieve and process them individually (Inmon 1995). Architecture of data warehouse consists of different logical layers (Inmon 1995). First layer is input or source layer, then processing layer, out put layer, decision support layer, etc. At source layer we have our data sources; these can be data bases, legacy system or data from web. After extracting this data from the source a process of transformation is applied on it to bring it into coherent format. Because data can be extracted from any type of sources, it contains