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Curated SQL Posts

Common Mistakes in T-SQL Code

Published 2024-02-23 by Kevin Feasel

Rich Benner builds a list:

One potential issue here is the lack of time to delve really deeply into each programming language at one’s disposal. The thing about SQL Server is that it is a language that performs very differently than, say, C#. Those languages are row based, which means it’s common to iterate through a data set and process each row individually. This works quite well in those languages, but quite terribly in SQL Server. Being a set-based language, SQL Server prefers to deal with the whole data set at once.

Because of these nuances, it’s easy for developers to make mistakes when creating SQL server code. Let’s go through some common errors that we see.

Read on for several common mistakes that we often find in our code.

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Adding Superscripts and Subscripts to Axis Labels in R

Published 2024-02-22 by Kevin Feasel

Steven Sanderson changes the script:

Before we dive into the code, let’s quickly review what superscripts and subscripts are.

  • Superscripts: These are smaller-sized characters or numbers that appear above the baseline of the text. They are often used to denote exponents or indices.
  • Subscripts: On the other hand, subscripts are smaller-sized characters or numbers that appear below the baseline of the text. They are commonly used in mathematical expressions or chemical formulas.

Read on to see how you can generate these in R visuals.

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GUID Conversion and the Serverless SQL Pool

Published 2024-02-22 by Kevin Feasel

Reitse Eskens hits a weird error:

One of the transformations is to change one primary key column from integer to GUID. This is something you can do with some trickery you’ll see in the code. But what I found was that, even though the primary key is unique, the GUID’s weren’t. And then the fun starts digging into the why…

Read on for the research Reitse performed. I don’t even have a good guess for this, it’s so weird. It feels like a bug but it’s weird regardless.

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Full and Incremental Loads in Microsoft Fabric

Published 2024-02-22 by Kevin Feasel

John Miner continues a series on data engineering in Microsoft Fabric:

In a data lake, we have a bronze quality zone that supposed to represent the raw data in a delta file format. This might include versions of the files for auditing. In the silver quality zone, we have a single version of truth. The data is de-duplicated and cleaned up. How can we achieve these goals using the Apache Spark engine in Microsoft Fabric?

Read on for John’s take on the answer. I’ve found that I have a fairly good answer for smaller datasets, though as the size of the data gets larger, the less I like answers for the raw layer.

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Community Updates to Community Stored Procedures

Published 2024-02-22 by Kevin Feasel

Erik Darling shares some updates:

If you’re the kind of person who needs quick and easy ways to troubleshoot SQL Server performance problems, and you haven’t tried my free scripts yet, you’re probably going to keep having SQL Server performance problems.

I don’t get a lot of visitor contributions to my code (and here I thought it was just because it’s perfect), but I had a couple cool recent additions to sp_QuickieStore, my free tool for searching and analyzing Query Store data.

Read on to see what’s new in a few procedures. Also, Die verboten Toten would absolutely be the name of my German punk rock or possibly DC hardcore style band.

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The Risk of Query Failure on Readable Secondaries in SQL Server

Published 2024-02-22 by Kevin Feasel

Kendra Little explains a problem:

If you use readable secondaries in Availability Groups or Read-Scale out instances in Azure SQL Managed Instance, you may have queries fail repeatedly if there is a glitch and statistics are not successfully “refreshed” on the secondary replica. Those queries may keep failing until you manually intervene.

This has been the case for a few years, and it’s unclear if Microsoft will fix this. There is a well established support deflection article which documents the issue and provides ‘workarounds’.

Read on for Kendra’s thoughts. I haven’t run into this before, myself, but I also don’t tend to make very heavy use of readable secondaries.

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Updating Records in a Kusto Database

Published 2024-02-21 by Kevin Feasel

Vincent-Philippe Lauzon shows off a feature now in public preview:

Kusto databases, either in Azure Data Explorer or in Fabric KQL Database, are optimize for append ingestion.

In recent years, we’ve introduce the .delete command allowing you to selectively delete records.

Today we are introducing the .update command.  This command allows you to update records by deleting existing records and appending new ones in a single transaction.

This command comes with two syntaxes, a simplified syntax covering most scenarios efficiently and an expanded syntax giving you the maximum of control.

Read on for more information and a pair of examples of how updating works.

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Transactional Replication in SQL Server on Linux

Published 2024-02-21 by Kevin Feasel

I finish up a series on SQL Server on Linux:

In this video, we will briefly cover the various forms of replication available in SQL Server, as well as what is in SQL Server on Linux. Then, we will create a simple publication and subscription using T-SQL.

As I joke about in the video, this is the video I expect to get the least traction on, if only because DBAs tend to run away from replication. If I were 20% more inclined toward Quixotic endeavors, I’d create an entire series on replication and show that it’s not magic and it’s only 70% as painful as most DBAs think, and even that’s because there’s a relatively limited amount of information out there on how things work.

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Renaming a Column in Microsoft Fabric via Python Notebook

Published 2024-02-21 by Kevin Feasel

Gilbert Quevauvilliers performs a rename:

I thought it would be good to help others in terms of my learning journey when working with partner notebooks and Microsoft fabric.

In today’s blog post, I am going to show you how to rename a column. In my experience this came up because I had a column name which had a forward slash “/” in it which caused the loading of the data for the table to fail because this is a reserved character.

Read on for the code an example of how it works in action.

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Power BI Visual Calculations Now Available

Published 2024-02-21 by Kevin Feasel

Marc Lelijveld jumps into a new feature:

You might have seen some buzz around already, although the official blog post is not out yet, the February release of Power BI desktop is already available to download. After a month waiting (traditionally, there is no January update) it has some great new features in it! Not only Tabular Model Definition Language is there now, but more towards solution development, we now have Power BI Visual Calculations! It was announced for a while already, the more excited I am that we finally can start exploring Visual Calculations in practice!

Read on to learn what a visual calculation is and why it’s a big deal.

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