Sql-Server

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:

You are reviewing the design of a database and note that in the dbo.Customers table, there is a column called CustomerTimestamp that has the timestamp data type.

Can you extract the date from the CustomerTimestamp column by using the CONVERT function?

2026-01-08

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: Administration Level: Medium

Question:

You are tracing queries using Extended Events. Two queries have exactly the same execution plan, and the same plan costs. In the trace, one query showed a duration of 2 minutes. The other query showed a duration of over an hour.

2026-01-07

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: Administration Level: Intro

Question:

You successfully create a full backup of a database that is in full recovery model.

As part of the backup, is the transaction log shrunk?

Answer:

No — a full database backup does not shrink or truncate the transaction log.

2026-01-06

I can’t tell you how many sessions for developers that I have attended, where the demonstration shows an application connecting to a database as the database owner (dbo) or as a system administrator (like sa). Are we then surprised when developers do this in their own applications?

Please don’t do this.

If you’re running a utility application that’s only used by administrators, and is run within a secure part of the environment, that might be ok. But for normal user applications, it’s just not safe to do so, and it’s really poor practice.

2026-01-05

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: Administration Level: Intro

Question:

You are configuring database mail so that applications can send emails.

Does database mail have a dependency on Microsoft Exchange ?

Answer:

No, Database Mail does not depend on Microsoft Exchange.

Database Mail in SQL Server:

2026-01-04

If you are working with really long script files in SSMS, you might need to work on more than one part of the script at the same time. Perhaps you need to work on a function, and also on the code that calls the function.

On the Window menu, there is a Split option.

When you first do this, you’ll see a split window with the same query at top and bottom:

2026-01-03

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: Administration Level: Intro

Question:

You are using Object Explorer in SQL Server Management Studio (SSMS) to browse the contents of a SQL Server. In the System Databases folder, there is a database named model. What is its purpose?

2025-12-31

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:

Does a stored procedure automatically provide a transaction i.e., if a statement within a stored procedure fails, are all previous data modification statements rolled back?

Answer:

No, a stored procedure does not automatically provide an implicit transaction.

2025-12-30

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: Administration Level: Advanced

Question:

When checkpoint writes occur, is only committed data written, or is uncommitted data written?

If only committed data, explain why.

If both, explain why.

Answer:

Checkpoint is a background process that:

• Flushes dirty pages (pages in memory that have been modified since they were read from disk) to disk.
• Records a log sequence number (LSN) in the transaction log that marks the point at which the database is known to be consistent on disk.

This means that SQL Server doesn’t flush only committed transactions — it flushes all dirty pages, whether the transactions that modified them are committed or not.

2025-12-28

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: Administration Level: Advanced

Question:

You know that the master database in SQL Server is now separate to the resource database (mssqlsystemresource).

Can you list three types of instance-level metadata that still live in the master database?

Answer:

2025-12-27