Book Image

Data Modeling for Azure Data Services

By : Peter ter Braake
Book Image

Data Modeling for Azure Data Services

By: Peter ter Braake

Overview of this book

Data is at the heart of all applications and forms the foundation of modern data-driven businesses. With the multitude of data-related use cases and the availability of different data services, choosing the right service and implementing the right design becomes paramount to successful implementation. Data Modeling for Azure Data Services starts with an introduction to databases, entity analysis, and normalizing data. The book then shows you how to design a NoSQL database for optimal performance and scalability and covers how to provision and implement Azure SQL DB, Azure Cosmos DB, and Azure Synapse SQL Pool. As you progress through the chapters, you'll learn about data analytics, Azure Data Lake, and Azure SQL Data Warehouse and explore dimensional modeling, data vault modeling, along with designing and implementing a Data Lake using Azure Storage. You'll also learn how to implement ETL with Azure Data Factory. By the end of this book, you'll have a solid understanding of which Azure data services are the best fit for your model and how to implement the best design for your solution.
Table of Contents (16 chapters)
1
Section 1 – Operational/OLTP Databases
8
Section 2 – Analytics with a Data Lake and Data Warehouse
13
Section 3 – ETL with Azure Data Factory

Designing Satellite tables

Hubs and Links only contain keys. Hubs only contain the business keys of entities, not descriptive data of those entities. Links only contain foreign keys to Hubs or other Links, but again, no descriptive data. We do create the LoadDate and Source columns, but these are not real descriptive data of the entities or the relationships. We add Satellite tables to the main structure of the Data Vault as defined by the Hubs and the Links. Satellite tables, or just Satellites, contain the "real" data, the descriptive data. This, of course, includes non-unique data values such as product color.

A Satellite is a table containing detailed and historical descriptive data columns of a Hub or a Link. Figure 9.8 shows a Satellite:

Figure 9.8 – Satellite table

A Satellite has the following columns:

  • The hash key of the Hub or Link it belongs to
  • The load date of the row
  • The end date of the row
  • The actual descriptive...