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Day: November 15, 2024

Using the subset() Function in R

Published 2024-11-15 by Kevin Feasel

Steven Sanderson plays duck-duck-goose with the data:

Data manipulation is a cornerstone of R programming, and selecting specific columns from data frames is one of the most common tasks analysts face. While modern tidyverse packages offer elegant solutions, Base R’s subset() function remains a powerful and efficient tool that every R programmer should master.

This comprehensive guide will walk you through everything you need to know about using subset() to manage columns in your data frames, from basic operations to advanced techniques.

Click through for a description of the function and examples of it in action.

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Tenant Switching in Microsoft Fabric

Published 2024-11-15 by Kevin Feasel

Koen Verbeeck has good news:

Praise whatever deity you believe in, because it’s finally here, a tenant switcher for Microsoft Fabric (which includes Power BI). A what? Let me explain. When you have a organization with multiple tenants in Azure (also called directories in some products like Azure Devops), or you’re a consultant like me who works with multiple clients (with each their own tenants), it’s possible that you can log into multiple tenants using the same email address. This can happen if your user account was added as an external user to another tenant.

This has been a real pain, and unfortunately, that pain still exists for Power BI Desktop.

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Hyperthreading and Warehouses

Published 2024-11-15 by Kevin Feasel

Joey D’Antoni covers the impact of hyperthreading on warehouse performance:

Database performance, especially in the cloud, is always a big concern. Traditionally, cloud storage has not performed as well as high-end on-premises storage. The introduction of faster cloud storage (in Azure Premium V2 and Ultra Disk, in AWS IO1-3) and VMs with more available storage bandwidth has improved overall storage performance. However, storage is only sometimes the complete picture.

Read on for Joey’s tests and findings.

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The IS Operator in T-SQL

Published 2024-11-15 by Kevin Feasel

Eric Blinn wants to know of those NULLs:

Many data professionals search for help writing T-SQL queries containing columns with NULL values in a Microsoft SQL Server table. Some of the most common NULL functions include IS NULL, IS NOT NULL, NOT NULL, NULL, what is NULL, NULL vs NOT NULL, etc. In this SQL tutorial, the goal is to help you better understand how to work with NULL values in a SQL database.

Even the best of us have accidentally used = NULL in a script when we meant IS NULL. Which is totally different from ISNULL(), of course. And NULLIF(), naturally.

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Learn from Developer Edition rather than Express Edition

Published 2024-11-15 by Kevin Feasel

Vlad Drumea learns the right way:

It’s free for non-production use

Just like SQL Server Express Edition, Developer Edition is free, but, unlike Express, it’s only free for non-production purposes (developing, testing, demoing, learning).

If you want to learn more about this, Bob Ward has a blog post that covers this in-depth and answers some questions that people tend to have about Developer Edition.

Back in the day, Developer Edition used to cost money—something like $50, so not much, but just enough to make people prefer Express Edition. Those days are long gone, however.

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