Tagged: Hub


Unknown keys (zero keys or ghost keys) in Hubs for DV2.0

I am still working towards capturing the generation (using BIML in SSIS) and virtualisation (using views / SQL) of the Presentation Layer (in a Dimensional Model). But before we get there, some topics need to be addressed first. One of these is the requirement to have ‘unknown’ keys available in the Hubs. Thankfully, this is one of the easiest concepts to implement. The basic idea is that you create a dummy record in the Hub which...


Data Vault ETL Implementation using SSIS: Step 3 – Hub ETL – part 2 – SQL selection

The outline ETL for Data Vault Hub style ETL using SSIS has been documented in ‘Hub implementation’ and ‘Hub exceptions’. As a minor addition I would like to dive a bit deeper into the selection logic associated with Hub ETL. Following the experiences ‘from the trenches’ there are basically two ways to create SQL for a Hub selection from the Staging Area; Straight-up selection of the business key Selection including a composite business key (e.g. assembled from...


Data Vault ETL Implementation using SSIS: Step 3 – Hub ETL – part 1 – overview

The Staging Area and Historical Staging, both part of the conceptual Staging Layer, are not directly related to Data Vault although at least the Staging Area ETL paves to way with the definition of the Event Date/Time. The Hub however is the first true Data Vault template to be implemented in SSIS. Please note that this is true for DV1.0; for DV2.0 the Staging Area is incorporated into the design a bit more. The Hub...