Designing business vaults
The first version of the Data Vault theory introduced the notion of Hubs, Links, and Satellites. This provided the flexibility over time that we needed for data warehousing. Data Vault 2.0 has a couple of adaptions to the first version. An important change was the introduction of hash keys. But Data Vault 2.0 also introduced the concept of a business vault. This addresses the fact that the structure of a Data Vault as discussed until now will rapidly become complex and difficult to query. The latter leads inevitably to bad query performance.
The introduction of the business vault led to two other new terms: Raw Data Vault and Operational Data Vault. Both terms mean the same and refer to a "pure" Data Vault structure with Hubs, Links, and Satellites as discussed so far in this chapter. The Raw Data Vault stores raw data coming directly from the source database. The columns are stored in different table structures, but the data itself is not changed...
