Azure-Sql-Db

This is the twelfth tale in a series of stories about data. I hope you enjoy the series.

Today’s tale relates to a SQL Server Integration Services (SSIS) package. It used the same architecture as other packages and on the same server, and even though it said it was successful, nothing happened. Let’s discuss why.

Some background information

At the site, a separate SSIS server (using an earlier version of SQL Server i.e., 2014) had been deployed. The server was used to run all the organization’s SSIS packages. These packages connected to several data sources:

2025-11-17

This post describes how the object dependency tracking views provide more reliable insights into object dependencies than previous methods such as the use of the sp_depends system stored procedure.

During a recent consulting engagement, I was asked about the best way to determine which stored procedures and views made use of a particular table. In the past, the methods available from within SQL Server were not very reliable. Way back in SQL Server 2008, significant improvements were made in this area, yet I see so few people using them, at least not directly. Many will use them indirectly via SSMS.

2025-11-14

This second article in a two-part series shows you how to control the execution context of stored procedures. This time, it’s by using digital signatures and code signing.

During a recent consulting engagement, I noticed that the client needed to control the security context a stored procedure was running under but was using a convoluted method to do so. Changing the security context that stored procedures run under is a common requirement, letting users execute code via stored procedures that they aren’t allowed to execute directly.

2025-11-10

This is part 1 of a two-part series that shows you how to use the EXECUTE AS clause to change and control security context for stored procedures. Up next month will be digital signatures.

During a recent consulting engagement, I noticed that the client needed to control the security context that a stored procedure was running under but was using a convoluted method to do so. Changing the security context that stored procedures run under is a common requirement, letting users execute code via stored procedures that they aren’t allowed to execute directly.

2025-11-06

Uniqueness can be implemented by primary keys, unique constraints and unique indexes. The use of primary keys is well understood but confusion exists about unique constraints and unique indexes.

This issue arose from a consulting engagement I was performing earlier in the month. During one of the architectural discussions I was having with the client, an interesting question was suddenly posed: When would you ever use a unique index?

After thinking about this for a moment, I suddenly realized that I almost never would use one and so I raised the topic on a technical discussion forum. An interesting discussion ensued and I’ve summarized the key thoughts in this article.

2025-11-02

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 trying to truncate a table but the command is failing.

Can you give some examples of what can cause a truncate command on a table to fail?

Answer:

One common reason is that the table is referenced by a FOREIGN KEY constraint. (But you can truncate a table that has a foreign key that references itself).

2025-10-31

We spend a lot of time doing performance tuning work for clients. Inappropriate indexing strategy is often high on the list of issues that we identify. Most of these issues can’t be fixed by SQL Server itself and require a detailed understanding of both how the tables are structured and how they are accessed.

However, there is one very common problem however that I believe SQL Server could assist with.

2025-10-21

This is the eleventh tale in a series of stories about data. I hope you enjoy the series.

Recently, I’ve written a series of articles on how the overall size of a financial services database was tamed by the application of table compression, XML compression, and PDF size reduction. I have applied this approach at many sites but recently came across one where the outcome seemed to constantly be getting worse rather than better. Every time I tried to improve the situation, it got worse. Let’s discuss why.

2025-10-13

This is the tenth tale in a series of stories about data. I hope you enjoy the series.

I regularly see code that calculates a count of a set of rows then makes a decision that’s based on the count, but only on whether or not the count is zero. Consider this (slightly contrived) example based on AdventureWorks:

DECLARE @PersonCount int;

SELECT @PersonCount = COUNT(*)
FROM Person.Password
WHERE BusinessEntityID = 12
AND PasswordHash = 0x208394209302;

IF @PersonCount > 0
BEGIN
    PRINT N'Password matches';
END;

Now I’ll start by saying that the last thing I’d ever want to see in SQL Server code is this sort of playing around with users and passwords, but I’m ignoring that for now.

2025-10-09

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 reviewing your development standards and notice that there is a warning about making sure you don’t nest views.

Why would this be an issue?

Answer:

Nested views hide complexity, and worse, the SQL Server optimizer might not be able to eliminate all the tables from the query that it could otherwise have done. This can lead to serious performance issues that could have been avoided.

2025-10-07