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 Link tables

A Link table, or just Link, can be one of the following two things:

  • A relationship between two or more Hub tables
  • A (business) transaction

Before we go into these two cases, have a look at Figure 9.6. Figure 9.6 shows the column structure of a Link table:

Figure 9.6 – Link table

A Link consists of two or more foreign keys. These can be hash keys from Hubs or from other Links. Like Hub tables, Link tables have a LoadDate column and a Source column. The primary key of a Link table is the hash value calculated over all the foreign keys together with the load date. The foreign keys are, of course, hash values themselves because they reference the hash keys of the Hub tables. The columns shown in Figure 9.6 are mandatory and should always be created in the order shown. This makes automatically generating Link tables easier, the same argument as used for Hub tables.

You can choose to add some optional columns, such...