Essay Data Warehousing
Delvin and Murphy as noted earlier defined a data warehouse as a “single logical storehouse of all the information used to report on the business” (Bouman & van Dongen, 2009). Bill Inmon, the father acknowledged father of data warehousing described a data warehouse as “subject oriented, time variant, nonvolatile, and integrated collection of data in support of management decisions” (Inmon, 1996 in Ponniah, 2010). According to Inmon, data warehouses as subject oriented where all entities and events relating to a specific subject are linked together, time variant where all changes to the data are tracked to enable reporting that shows changes over time, nonvolatile where data that is entered into the data warehouse is never overwritten or deleted, and integrated where the data warehouse contains data from multiple source systems after being cleaned and conformed (Bouman & van Dongen, 2009).
In light of the above definitions, a data warehouse in simple terms can be defined as a pool of integrated data designed to support managerial decision making and solving functions. The databases involved serve as a repository of detailed current and historical data of many categories, subjects, or areas which tend to be of potential interest to managers throughout the organization (Turban, Sharda & Delen, 2010).
Data warehouse maintains