Great article and information (glad it was reposted on SQLServerCentral today)!

In regard to item #10 - while not denormalizing tables definitely applies to transaction systems (OLTP) - so order entry and other application transaction systems retain their integrity and update efficiencies - the presentation tables in a data warehouse (OLAP) are usually denormalized (as a star schema) to improve performance (and to a lesser extent understandability for the report creation users). This storage of redundant data in data warehouses is deemed worthy to reduce report query response time by limiting the depth of the table joins.

A properly designed star schema for the data warehouse presentation fact and dimension tables makes sure the large fact tables are using foreign keys (and the corresponding primary key in the dimension table) of appropriate size for both space saving and performance reasons and also espected growth as you specified in your article for transaction tables. Also numeric and string fields in both the fact (very important because fact tables get very large) and dimension tables would benefit from the space saving techniques you specified.

Thanks again,

Chris Reeve