One of the key components of the business intelligence (BI) architecture is a semantic layer. The semantic layer provides a translation of the underlying database structures into business user oriented terms and constructs. It is usually part and parcel of the query and reporting tool. OLAP or cube databases also include a BI semantic layer. […]

Drilling across separate business processes is one of the most powerful applications in a data warehouse. We often describe drilling across as magic: separately open connections to the dimensional models for each business process, fetch answer sets from each process labeled identically with row headers drawn from specially conformed dimensions, then deliver the result by […]

Many organizations are embracing agile development techniques for their DW/BI implementations. While we strongly concur with agile’s focus on business collaboration to deliver value via incremental initiatives, we’ve also witnessed agile’s “dark side.” Some teams get myopically focused on a narrowly-defined set of business requirements. They extract a limited amount of source data to develop […]

Ralph introduced the concept of slowly changing dimension (SCD) attributes in 1996. Dimensional modelers, in conjunction with the business’s data governance representatives, must specify the data warehouse’s response to operational attribute value changes. Most Kimball readers are familiar with the core SCD approaches: type 1 (overwrite), type 2 (add a row), and type 3 (add […]