Building the Data Warehouse

Скачать в pdf «Building the Data Warehouse»
Data Homogeneity/Heterogeneity


At first glance, it may appear that the data found in the data warehouse is homogeneous in the sense that all of the types of records are the same. In truth, data in the data warehouse is very heterogeneous. The data found in the data warehouse is divided into major subdivisions called subject areas. Figure 2.28 shows that a data warehouse has subject areas of product, customer, vendor, and transaction.


The first division of data inside a data warehouse is along the lines of the major subjects of the corporation. But with each subject area there are further subdivisions. Data within a subject area is divided into tables. Figure 2.29 shows this division of data into tables for the subject area product.






product customer









transaction


Figure 2.28 The data in the different parts of the data warehouse are grouped by subject area.

Скачать в pdf «Building the Data Warehouse»