Aggregate tables are summary tables that store data at higher levels than it was stored when the data was initially captured and saved. Aggregate tables provide quicker access to frequently requested information, while retaining the traditional power of ROLAP to directly query the database to answer any questions. This section describes how and why aggregate tables are used.
MicroStrategy creates aggregates only on fact tables since lookup tables and relationship tables are usually significantly smaller. To understand aggregate tables, you should be familiar with fact tables in the context of data modeling and data warehousing. For more information on these topics, see The Logical Data Model, Warehouse Structure for Your Logical Data Model, and The Building Blocks of Business Data: Facts.