Abstract
For a couple of decades, data and database management system has been evolving steadily and extensively to make data available for almost all of the commercial applications such as ERP, CRM, SCM that handle on-going day-to-day operations including business status update, record accumulation and reporting. These data are in two-dimensional tabular format called "Relational" and are typically involved in transaction processing. On the other hand, in order to make data available for high-level decision-makers, two types of extensions were made. One extension was made in a number of dimensions known as "Data Warehouse" and the other was in attributes to accommodate structured or nested relations known as "Nested Relational Database (NRDB)", which allow users to ask summarized and high-level questions more intuitively.