The idea of the Virtual Data Warehouse was conceived as a result of working on improvements for generation of Data Warehouse loading processes. It is, in a way, an evolution in ETL generation thinking. Combining Data Vault with a Persistent Historical Data Store provides additional functionality because it allows the designer to refactor parts of the Data Warehouse solution. Hybrid approaches for Data Warehousing are designed to be flexible, to be adaptable to accommodate changes in business use and interpretation. Working with data can be complex, and often the ‘right’ answer for the purpose is the result of a series of iterations where business Subject Matter Experts and data professionals collaborate.
In other words, the Data Warehouse model itself is not always something you always can get right in one go. In fact, it can take a long time for a Data Warehouse model to stabilise, and in the current fast-paced environments this may even never be the case. The Virtual Data Warehouse helps maintain both the mindset and capability for a data solution to keep evolving with the business, and to reduce technical debt on an ongoing basis. This mindset also enables some truly fascinating opportunities such as the ability to maintain version control of the data model, the metadata and their relationship - to be able to represent the entire Data Warehouse as it was at a certain point in time - or to even allow different Data Models for different business domains.