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Day: September 11, 2023

Statistical Tests in R

Adrian Tam tries out a couple of tests:

R as a data analytics platform is expected to have a lot of support for various statistical tests. In this post, you are going to see how you can run statistical tests using the built-in functions in R. Specifically, you are going to learn:

  • What is t-test and how to do it in R
  • What is F-test and how to do it in R

This is one of the things that R does best among any language: statistical testing. R has support for an enormous number of statistical functions, either built into the base language or available as packages.

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Plotting a Subset of Data in R

Steven Sanderson doesn’t need all of those data points:

Data visualization is a powerful tool for gaining insights from your data. In R, you have a plethora of libraries and functions at your disposal to create stunning and informative plots. One common task is to plot a subset of your data, which allows you to focus on specific aspects or trends within your dataset. In this blog post, we’ll explore various techniques to plot subsets of data in R, and I’ll explain each step in simple terms. Don’t worry if you’re new to R – by the end of this post, you’ll be equipped to create customized plots with ease!

Click through for several techniques for subsetting data, as well as reasons why you might want to do it.

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Microsoft Fabric Presentations

Wolfgang Strasser opens a vault:

Are you searching for Microsoft Fabric Presentations? You want learn more about the new unified analytics solution?

There are plenty of presentation available around the internet – some only as recordings, some as PDFs only.

BUT – last week, I found a (now not more) hidden gem of Microsoft Fabric content on the internet – the Microsoft Fabric Readiness repository

Click through for the link to those presentations.

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A SQL Server Security Checklist

Hemantgiri Goswami has a list and checks it twice:

Last week, in my previous article on How to Secure SQL Server I have discussed a few points that can help you secure SQL Server. In this post, as promised I will share a SQL Server Security Checklist that I have used for many of my clients to help them achieve PCI compliance.

As you are aware, PCI is global payment security standard council. Following their standards help an organization achieve a compliance certificate that all the card data that is processed, store and transmit are maintained in secure environment.

The good news is that you can use the dbachecks suite to check many of these items.

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PGSQL Phriday 012 Roundup

Ryan Booz goes beyond a short summary:

I think due to a number of people attending a PostgreSQL conference during the week blogs would have been written, and the ongoing runup to a pending release, participation this month was lower than normal. But the blog posts (and audio podcast) that we did receive were top-notch and I’m genuinely thrilled to see people make the effort. Keep an eye on these blogs for other content, because the quality of their work is excellent and you’ll surely learn new things with anything new they produce!

Read on for Ryan’s review of three blog posts and one podcast.

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Row-Level Security Performance and Troubleshooting

Ben Johnston digs into row-level security:

There are two main areas where RLS can impact performance. The first is the user or authentication lookup. Some kind of lookup must be performed in the access predicate to determine either the user name, group membership, or specific values in the session context. Considering that RLS is non-prescriptive, the lookup isn’t confined to these methods, but they are very easy methods to use and implement and are standard based on implementations I’ve seen.

The second area is the authorization lookup. The authorization lookup, checking if a user has access to particular rows, can have a much bigger impact on performance. This is also in the access predicate. Following the basic rules for performance and keeping lookups simple goes a long way to minimizing the impact of RLS on performance. The goal is to keep performance levels as close as possible to a table without RLS. If indexes and predicates are correct, RLS can improve performance in some situations due to the automatic filtering that happens.

Read on for Ben’s thoughts on the topic.

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SQL Shades for SSMS

Peter Schott prefers dark mode:

For those of us who’ve worked with SQL Server for some time, we’ve regularly used SQL Server Management Studio (SSMS). In recent years, we’ve seen an increase in websites and applications offering a Dark Mode. Azure Data Studio has one built in as it’s based on the VS Code engine. SSMS is a form of the full Visual Studio IDE and offers some ability to skin, but attempts in the past to make a true dark mode have been only partially successful. Microsoft has not given us that option in SSMS as it’s been more work than they can commit to with a broad platform. So our options have been partial dark modes, which leave big portions of the interface a bright white, or just use the defaults with everything being light.

Click through to see how SQL Shades does in Peter’s estimation. As for me, I’ll stick with my light mode.

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Thoughts on Third-Party Power BI Tools

Chris Webb shares some thoughts:

Rather than blog about the tool itself – there’s no point repeating Nikola’s post – I thought it would be good to answer a question someone asked me later that day about Tabular Editor and which I’m definitely going to be asked about DAX Optimizer, namely:

This looks great, but it’s expensive and it’s hard for me to get sign-off to use third-party tools like this. Why doesn’t Microsoft give me something like this for free?

Chris shares his personal opinions on the matter. My opinion on it, as someone who has worked with Microsoft products for a long time and never for Microsoft, is that Microsoft needs to play a balancing act. They build products and tools with the intention of third parties extending them, whether by opening up APIs or creating an explicit extensions marketplace (like we see in Azure Data Studio and Visual Studio Code). If they go and take the best bits of these third party products, then that third party marketplace dries up quickly. On the other side of the coin, depending on third parties can’t always cut it. For example, Azure Data Studio used to have an awful execution plan viewer and the answer was “use SentryOne Plan Explorer instead.” That wasn’t a great solution either for Azure Data Studio (and today, I don’t know if the extension is even still around), so the pushback was firm: a good execution plan reader needs to be a core part of any first-class SQL Server developer tool from Microsoft.

Chris has plenty to say on the topic as well.

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