Bottom-up approach: First, the data is extracted from external sources (same as happens in top-down approach). Then, the data go through the staging area (as explained above) and loaded into
data marts instead of datawarehouse. The data marts are created first and provide reporting capability. It addresses a single business area.
In the "Bottom-Up" approach, a data warehouse is described as "a copy of transaction data specifical architecture for query and analysis," term the star schema. In this approach, a data mart is created first to necessary reporting and analytical capabilities for particular business processes (or subjects).
The Bottom-up Approach This approach was coined by
Kimball as it can be defined as data after extraction from the source is cleansed and transformed by the staging area, after which the data is sent to the data marts of each theme/subject, and then it is loaded up in the data warehouse.According to the Wikipedia, the design methodologies of data warehouses are: Bottom-up design : In the bottom-up approach,
data marts are first created to provide reporting and analytical capabilities for specific business processes. These data marts can then be integrated to create a comprehensive data warehouse.
