Press "Enter" to skip to content

Curated SQL Posts

Alternatives to GREATEST and LEAST in SQL Server 2022

Published 2023-09-19 by Kevin Feasel

Drupal Grupal gives us alternatives:

If you haven’t already heard, SQL 2022 has introduced a new built-in system function called GREATEST. Simply put, it is to a set of columns, variables, expressions etc. what the MAX function is to a set of values (i.e., rows) of a single column or expression. The opposite of GREATEST function is LEAST function which returns the smallest value from the supplied list of columns, variables, constants etc. GREATEST & LEAST can be considered a pair, just as MIN/MAX functions are.

In other situations, GREATEST() and LEAST() are known as ARGMAX() and ARGMIN(), respectively.

Drupal shows us two alternatives to the built-in function and includes a performance comparison.

Comments closed

Dueling Sequences for Positive and Negative Numbers

Published 2023-09-19 by Kevin Feasel

Jose Manuel Jurado Diaz hears banjo music:

SQL Server’s INT data type, by design, provides a range from -2,147,483,648 to 2,147,483,647. But often, developers only utilize the positive range for primary keys and other identifier fields, effectively wasting half of its potential. What if we could harness this full range to temporarily extend the capacity of an INT column? In this article, we explore this idea in-depth.

I’m of two minds here. On the one hand, surrogate keys don’t have a meaning (by definition!), so it doesn’t really matter if that number is positive or negative. Also, including negative numbers makes sense when you expect the steady state table size to be above 2 billion but below 4 billion rows (assuming that you’re using an INT datatype), or you’ve found out that the steady state size is that big after the fact.

On the other hand, I don’t like having a caller define whether they want positive or negative values, as that now imbues meaning to the surrogate key, where positive keys mean one thing and negative keys mean another.

Comments closed

Microsoft Fabric Data Warehouse in a Database Project

Published 2023-09-19 by Kevin Feasel

Kevin Chant creates a database project:

In this post I want to cover how you can share a Microsoft Fabric Data Warehouse Database Project with the new target platform.

Which is now possible thanks to the latest Azure Data Studio Insiders update. You can view the ‘Add projects support for Fabric DW‘ pull request in the public azuredatastudio GitHub repository.

Kevin takes us through creating the database project in Azure Data Studio and then using Azure DevOps or Azure Data Studio to deploy it back out.

Comments closed

Azure SQL Edge Update for September 2023

Published 2023-09-19 by Kevin Feasel

Kendal Van Dyke has an update for us:

The motivation behind these two updates is simple: we are listening to where and how our customers are using Azure SQL Edge.

In discussions with customers and hardware partners, we see that SQL Edge on AMD64 is the architecture of choice for production deployments and developers on Windows. SQL Edge on ARM64 has been primarily popular with developers writing SQL Server applications on Apple hardware with M1 and M2 chipsets because SQL Edge has, until recently, been the only version of SQL Server that will run in containers on Apple M1/M2 silicon.

There goes SQL Server on a Raspberry Pi.

Comments closed

An Overview of Flink SQL

Published 2023-09-18 by Kevin Feasel

Martijn Visser continues a series on Kafka and Flink:

In the first two parts of our Inside Flink blog series, we explored the benefits of stream processing with Flink and common Flink use cases for which teams are choosing to leverage the popular framework to unlock the full potential of streaming. Specifically, we broke down the key reasons why developers are choosing Apache Flink® as their stream processing framework, as well as the ways in which they are putting it into practice. These range from streaming data pipelines to train ML models, to real-time inventory management in retail and predictive maintenance in manufacturing.

Next, we’ll dive into Flink SQL, which is a powerful data processing engine that allows developers to process and analyze large volumes of data in real time. We’ll cover how Flink SQL relates to the other Flink APIs and showcase some of its built-in functions and operations with syntax examples.

I’m naturally predisposed to blog posts which validate Feasel’s Law, so of course I was going to pick this one to recommend.

Comments closed

ML with Keras and TensorFlow over Streaming Kafka Data

Published 2023-09-18 by Kevin Feasel

Paul Brebner gives us a streaming scenario for model training:

One of the goals of incremental learning is to train a model continuously from streaming data. Incremental learning from streaming data means you don’t need all the data in memory at once, and the model is as up-to-date as possible, which can matter for real-time use cases. The third driver for incremental learning that I mentioned in the previous blog is when there is concept drift in the data itself—but we’ll ignore this aspect for the time being. 

In the last blog we demonstrated batch training with TensorFlow, and mentioned that TensorFlow, being a neural network framework, has the potential for incremental learning—just like animals and people do. In this blog, we will set ourselves the task of using TensorFlow to demonstrate incremental learning from the same static drone delivery data set of busy/not busy shops that we used in the last blog. 

Read on to see the code, results, and warnings.

Comments closed

Selective Fire for Trigger Execution

Published 2023-09-18 by Kevin Feasel

Erik Darling holds trigger fire until he sees the whites in their eyes:

I was helping a client with an issue recently where they wanted to allow certain admin users to override changes currently in a table, but not allow anyone else to make changes.

The thing is, users had to be allowed to make other changes to the table, so it wasn’t something that could be handled easily with security features.

The example I’m going to show here is simplified a bit to get the code across to you, so keep that in mind.

This is a somewhat wacky scenario, but Erik does get it working.

Comments closed

Service Level Agreements (RPO and RTO) and SQL Server

Published 2023-09-18 by Kevin Feasel

David Klee wants to know how much downtime is acceptable to you:

Database professionals of the world – I have a question. Has your organization defined service level agreements (SLAs) for your data estate? I’m talking specifically the Recovery Point Objective (RPO) and Recovery Time Objective (RTO), and to have these defined not in an arbitrary number of nines, but in minutes or hours. If these aren’t defined from above, your business continuity plan is doomed to fail.

Read on to learn what RPO and RTO mean, how to think in terms of RPO and RTO, and some of David’s recommendations.

Comments closed

Where Git Repositories Store File Versions

Published 2023-09-18 by Kevin Feasel

Julia Evans digs into a folder:

Hello! I was talking to a friend about how git works today, and we got onto the topic – where does git store your files? We know that it’s in your .git directory, but where exactly in there are all the versions of your old files?

For example, this blog is in a git repository, and it contains a file called content/post/2019-06-28-brag-doc.markdown. Where is that in my .git folder? And where are the old versions of that file? Let’s investigate by writing some very short Python programs.

Read on to learn how you can parse it all out. And this is also reason number 3 why you don’t want to commit a large file to Git: even if you delete that file later, the contents will live in the .git folder forever, or at least until you take some manual action to excise it from Git’s history.

Comments closed