Chapter 8:​ Availability for Azure SQL

Ensuring your applications are available can be critical in the modern world. This chapter looks at various High Availability (HA) and Disaster Recovery (DR) features provided by Azure SQL.

Firstly, there’s a general discussion about HA/DR capabilities, highlighting automatic backups, point-in-time recovery, built-in HA, and Azure redundancy. All these features mean there’s much less infrastructure management for a company to undertake, leaving it to concentrate more on the applications themselves.

Next, backup and restore are examined in more detail, again highlighting automatic backups. Long-term retention backups are discussed, giving the option for longer holding periods. Azure allows the storing backups in a different geo-location, proving protection against data centre outages.

High Availability is further discussed in relation to the various service tiers, namely: General Purpose, Business Critical, and Hyperscale (hopefully these names indicate their underlying functionality).

The chapter ends with a look at various means of monitoring availability, covering database availability, backup and restore history, service availability, and replica status. There’s a useful section on failover reasons, and how they might be investigated using Resource Health within the Azure portal.

A very useful chapter, showing that Azure provides many HA/DR features natively, although you can choose additional options for extra protection.

Chapter 9:​ Extending Your Knowledge of Azure SQL

Having looked at deployment, configuration, security, performance, and High Availability, this chapter aims to extend your Azure SQL knowledge with a miscellany of topics.

The chapter opens with a look at features that extend Azure SQL, including: linked-severs, external tables, database mail, full-text search, and machine learning services.

There’s a brief look at SQL Agent (for Managed instance), and the SQL Database equivalent (Elastic jobs).

Despite our best efforts, errors can still occur. With this in mind, there’s a section on Azure support, covering: handling errors, stack dumps, and troubleshooting using Copilot. Finally, UserVoice can be used to contact Microsoft to provide input/feedback on Azure matters.

Best practices appear with time and usage. Luckily, others have gained experience, so you’re able to take advantage of their best practices. There are links for Best Practice documents for both Security and Performance. Lastly, there’s a useful reminder that Azure Advisor is a great place to look for recommendations for your Azure SQL, it offers recommendations for: cost, security, reliability, operational excellence, and performance.

This chapter was a very enjoyable read, offering plenty of advice on expanding the reach of Azure SQL, job management, support, and how to improve your systems.

Chapter 10:​ Beyond RDBMS

Here the author aims to integrate Azure SQL into the wider world of Azure. It opens with a look at features that are already in-the-box of Azure SQL (but perhaps little used or known), and then those features that are usually viewed as being outside traditional Relation Database Management Systems (RDBMS).

The in-the-box features are:

• JSON and RegEx
• Spatial
• Graph
• Columnstore
• Memory-optimized
• Ledger
• Query Intelligence

In each case, the meaning of each feature is discussed, and example uses and/or links provided. It’s interesting to note that the author still sees customers having problems that could be fixed using these existing features.

The outside-the-box features are:

• REST API integration
• Data API Builder, GraphQL
• Azure Functions
• Hyperscale, Serverless, Pools
• Containers, DevOps, GitHub
• AI
• Fabric

Again, in each case, the meaning of each feature is discussed, and example uses and/or links provided.

I suspect since AI and Fabric are currently very topical within the SQL community, they have been plucked from this section and included in the book’s subtitle (i.e. “The Next-Generation Cloud Database with AI and Microsoft Fabric”). Although AI (Copilot) is discussed in various chapters, AI and Fabric probably constitute less than 3% of the book.

This chapter provides a useful look at how Azure SQL can be extended using features that are both inside and outside the traditional database area.

Conclusion

This book is easy to read, having clear explanations and a good flow within and between chapters. It has helpful diagrams, and useful practical walkthroughs. A degree of humour is given that assists the reading.

It contains useful website links for further information, in fact, the book could easily be 20-50 times bigger if you read all the links.

The author acknowledges that sometimes, the images/instructions in the book may not match those in Azure itself (the product gets updated regularly).

Helpfully, where possible the author explains features in terms of any corresponding on-premise SQL Server features i.e. the audience is assumed to be SQL Server DBAs that want to know about the various types of SQL Server on Azure.

Although there is overlap between Azure SQL Managed Instance and Azure SQL Database, I suspect readers will have one or the other (or deal with one at a time), so having most chapters where they are discussed together, means having to selectively pick through the chapters… It might have been better to have a distinct chapter for each (in a similar manner to having the separate chapter on Azure SQL VM) - however, this would lead to more duplication.

I enjoyed the author’s clear and knowledgeable explanations, which are also in the author’s companion book, SQL Server 2022 Revealed, my review of which is here.

Ignoring the updated links and new screenshots, the book is perhaps 75% the same as the first edition. This is a good thing, since in my opinion, it is the definitive Azure SQL book. Perhaps the major recent change has been the integration of context-sensitive Copilot into Azure.

This book is ideal for SQL Server DBA veterans who want to make the transition to the SQL Server Azure environment.

Overall, this is still the best book I’ve read on using SQL Server with Azure.

For other recommendations of books on cloud computing see Cloud Computing Books Pick Of The Bunch