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Day: February 14, 2022

Guidance on SUMMARIZE() and ADDCOLUMNS() in DAX

Marco Russo has some advice for us:

Everyone using DAX is probably used to SQL query language. Because of the similarities between Tabular data modeling and relational data modeling, there is the expectation that you can perform the same operations as those allowed in SQL. However, in its current implementation DAX does not permit all the operations that you can perform in SQL. This article describes how to use ADDCOLUMNS and SUMMARIZE, which can be used in any DAX expression, including measures. For DAX queries, you should consider using SUMMARIZECOLUMNS, starting with the Introducing SUMMARIZECOLUMNS article. You can also read the All the secrets of Summarize article for more insights about inner workings of SUMMARIZE.

Read on to see how it all works.

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Using CHAR

Steve Jones wants to know if people are still using CHAR:

I ran across an article, titled When to use CHAR, VARCHAR, or VARCHAR(MAX), which struck me as something I never do. I mean, I do use varchar (and nvarchar), but I can’t remember the last time I actually created a char column. The article is worth a read, and it sets the stage for you to think about your database design process and the choices you make.

It’s Friday, and if you take a few minutes and think about the last few times you’ve added columns to a table have you used CHAR as a data type? Or do you default to varchar of any size as a general rule?

Yeah, using CHAR (or NCHAR, which you’d probably want to use instead) is pretty rare. This is a consequence of storage becoming much less of a constraint over the past couple decades, as well as considerable gains in efficiency for data platform products. (N)CHAR might be a little faster than (N)VARCHAR for certain operations and may be a bit more efficient for single-character columns, but I agree with Steve’s premise.

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Static Properties and Methods in Powershell Classes

Robert Cain continues a series on Powershell classes:

Over the last few articles we’ve been covering PowerShell objects. The first article in the series, Fun With PowerShell Classes – The Basics, covered the basics of using of the PowerShell class construct introduced in PowerShell version 5.

If you’ve not read it I’d suggest you do so now as we’ll be building on it in this article, as well as in the next two, as we explore the advanced capabilities of PowerShell classes. In this post we’ll cover the concept of static properties and methods.

Read on to see what’s special about static methods and properties. My well-founded biases: static methods are fine, great even (but remember that I’m very biased toward functional programming and away from object-oriented programming). Static properties are usually a bad idea, especially in multi-user applications.

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Server Variables with Azure DB for MySQL

Arun Sirpal shows how to see and set server variables in Azure’s MySQL offering:

If you have used MySQL before you will know about the system server variables, you know such commands as SHOW VARIABLES; You can access most of them via the Azure portal or connect to MySQL and issues the commands you come to know about.

Let’s see a quick example.

Click through for that quick example, including one minor difference from standard MySQL implementations.

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