CS614 Data Warehousing GDB Solution Spring 2013

A data mart can be defined as:

“An implementation of a data warehouse with a scope of contents and data warehouse functions which are restricted for serving a single department or part of an organization”.

So, we can conclude that a data mart is a sub set of data warehouse. Keeping the above facts in mind do you think that same modeling techniques used for data marts are also applicable for data warehouse? Justify your answer with logical reasons.

Solution: Third normal form modeling is a classical relational-database modeling technique that minimizes data redundancy through normalization. When compared to a star schema, a 3NF schema typically has a larger number of tables due to this normalization process.

3NF schemas are typically chosen for large data warehouses, especially environments with significant data-loading requirements that are used to feed data marts and execute long-running queries.

The main advantages of 3NF schemas are that they:

  • Provide a neutral schema design, independent of any application or data-usage considerations
  • May require less data-transformation than more normalized schemas such as star schemas