Azure-Sql-Db

Upcoming processors are likely to have even more cores than now. Have you ever tried to write multiprocessor-style code? A friend of mine recently said that he learned some of this style of coding but later when he came back to it, he realised how much he thought he knew but didn’t.

For languages like T-SQL, we don’t have inherent support for multi-threading. In fact, the only trace I can see of this in T-SQL today is the ability to have multiple readers on a service broker queue.

2025-12-22

This is a post in the SQL Interview series. These aren’t trick or gotcha questions, they’re just questions designed to scope out a candidate’s knowledge around SQL Server and Azure SQL Database.

Section: Development Level: Medium

Question:

You are writing a query that involves inner joins across five tables. Does the order of the tables within the query affect the query plan?

Answer:

No. SQL Server determines the best order for you to join the tables in.

2025-12-21

This is a post in the SQL Interview series. These aren’t trick or gotcha questions, they’re just questions designed to scope out a candidate’s knowledge around SQL Server and Azure SQL Database.

Section: Development Level: Medium

Question:

If you are SELECTing from a table and the ORDER BY clause in your query is in the same order as a non-clustered index, will the non-clustered index be used?

Answer:

It might or it might not.

2025-12-19

This is a post in the SQL Interview series. These aren’t trick or gotcha questions, they’re just questions designed to scope out a candidate’s knowledge around SQL Server and Azure SQL Database.

Section: Development Level: Intro

Question:

A developer in your team has suggested that better formatted and laid-out SQL code will perform better?

Is this true?

Answer:

Because the optimiser reduces queries down to a format that it can work with the format of your code doesn’t make a difference. Better formatted code is more readable and maintainable though, so it’s always a good idea.

2025-12-17

SQL Server has a number of built-in database roles. The ones I see used the most are db_datareader and db_datawriter. They let you either read from all tables or read and write from all of them. Curiously, what has never been supplied is a db_procexecutor.

Developers and administrators who set up the use of these permissions think they are at least not using dbo or sa and while that’s true,

2025-12-16

This is a post in the SQL Interview series. These aren’t trick or gotcha questions, they’re just questions designed to scope out a candidate’s knowledge around SQL Server and Azure SQL Database.

Section: Development Level: Medium

Question:

You have created a table named dbo.Customers. The column CustomerID has been declared as

INT NOT NULL IDENTITY(1, 1)

No contraints are defined on the table.

Can the CustomerID contain a duplicate value? If so, how?

Answer:

2025-12-15

When you create a new query file in SSMS, it automatically becomes part of a solution. You can view it in Solution Explorer. In this example, I have created two query files, and renamed the tabs without saving them, as Query 1 and Query 2:

They are in the Miscellaneous Files section as they weren’t part of a script project.

SSMS can now compare multiple files. If I highlight both the files, and right-click, I get this option:

2025-12-11

One surprise in the release plans for SQL Server 2025 is that SQL Server Reporting Services (SSRS) is being discontinued as a brand. If you have a paid license for SQL Server, you are now able to install Power BI Report Server. Previously, that option required you to have an Enterprise Edition license for SQL Server or a premium level license for Power BI.

But Reporting Services was also previously available for SQL Server Express. That will no longer be supplied, and there’s no option to use Power BI Report Server.

2025-12-10

This is a post in the SQL Interview series. These aren’t trick or gotcha questions, they’re just questions designed to scope out a candidate’s knowledge around SQL Server and Azure SQL Database.

Section: Development Level: Medium

Question:

If you have two values where you want to return the first if it’s not NULL, and otherwise return the second, is there any difference at all between using the ISNULL and COALESCE functions?

2025-12-09

Anyone who has worked with SSMS for long, will have the experience of opening a number of query windows for short-term work, not wanting to save the scripts, and then being unable to find the one they want in the drop-down list of scripts:

The alternative to this was to save them all somewhere so you could give them a name. Then you need to clean them all up later.

2025-12-08