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Month: February 2023

Collaboration in Power BI Workspaces

Published 2023-02-06 by Kevin Feasel

Reza Rad takes us through the workspace model in Power BI:

Workspaces are another way of sharing Power BI content with other people. The benefit of this sharing approach is that you can share content with a group of people and create a collaborative development environment where everyone can access it. In this article and video, I get you through sharing with workspaces, what the limitations and advantages are, and how it is different from dashboard sharing, and you will have a complete understanding at the end of this article which scenarios are suitable to be used with this method of sharing.

Click through for a video and an article.

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The Importance of Star Schemas in Power BI

Published 2023-02-06 by Kevin Feasel

Paul Turley lays out facts (and dimensions):

There is no secret about this. If you do any legitimate research about Power BI (reading blogs, books or training from reliable sources), you will quickly learn that a lot of basic functionality requires a dimensional model, aka “Star Schema”. This is a hard fact that every expert promotes, and self-taught data analysts either have learned or will learn through experience. So, if everyone agrees on this point, why do so many resist this advice?

Perspective is everything. I didn’t understand why getting to the star schema was so out of reach so often until I was able to see it from another perspective. There are a few common scenarios that draw source data into different directions than an ideal dimensional model.

Read on for Paul’s take on the subject.

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Antipattern Queries Extended Event in SQL Server

Published 2023-02-06 by Kevin Feasel

Bob Ward enumerates some anti-patterns SQL Server can guilt you over:

If a query uses certain antipatterns, it will be detected during query optimization.  For both SQL Server and Azure SQL (internally on by default), if these antipatterns are detected when optimizing the query, and the query_antipattern event has been added as part of a running extended event session, the output will be captured.  The output will contain the relevant capture fields configured for the extended event session, allowing one to quickly identify which queries contain these antipatterns and are, therefore, prime candidates for tuning.

Read on for more information about this extended event, which is new to SQL Server 2022. I haven’t used this yet, so the two caveats I’m about to give are speculative in nature…though when has that ever stopped me? Caveat the first: just because something shows up as an anti-pattern doesn’t mean it needs to be fixed. There can be good reasons why you have chosen what is normally a less-efficient path. Caveat the second: just because something doesn’t show up as an anti-pattern doesn’t mean it’s fine. These are likely directional and my guess is that SQL Server will be fairly conservative in its estimation of what constitutes an anti-pattern so that you don’t get a lot of false positives.

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Rotating TDE Certificates

Published 2023-02-06 by Kevin Feasel

Matthew McGiffen switches out a certificate:

In terms of encryption, Key Rotation is the process of replacing your encryption keys on a periodic basis. This is considered good practice and is required by many security certifications.

In practice, if you had to rotate/replace the key that is used to encrypt your data then that would be an intensive activity requiring all your data to be decrypted with the old key before being replaced with the new. This could also create a vulnerability where data sits in an unencrypted state during the process.

Instead, see what SQL Server does by reading Matthew’s blog post.

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Power BI Report Source Redirection

Published 2023-02-06 by Kevin Feasel

Dan English re-binds some reports:

This is a follow up to the post Azure Analysis Services (AAS) Migration to Power BI Premium Experience that I did back in December. In that post I mentioned the following towards the end of the post –

If you have existing Power BI reports using the AAS live connection you are able to use the report rebind API to point the report to use the Power BI dataset. The one thing to note as pointed out in the documentation is that as of now if you need to modify the report layout you would need to do that directly in the service. That portion of the migration process is still being worked on and hopefully should be updated to resolve the issue so that you will be able to download the redirected report from the service, modify it, and then publish the report back to the Power BI service.

In this post I want to touch on this a bit more and provide some follow up based on work that has taken place since that post on the migration rebind (redirection) process.

Dan shows the process and also tells us about a gotcha along the way.

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Dealing with Imbalanced Class Data for Image Classification

Published 2023-02-03 by Kevin Feasel

Alexander Billington needs more beta carotene:

Image classification is a standard computer vision task and involves training a model to assign a label to a given image, such as a model to classify images of different root vegetables. A big problem with classification is bias, and the models favouring a particular image class above the others. A common cause of this can be dataset imbalance, and it is often hard to spot as a model trained on an imbalanced dataset can often still have good accuracy. E.g. if there are 1000 images in the test dataset, 950 potatoes and 50 carrots and the model predicted all 1000 images to be potatoes it would still have 95% accuracy. This is also an example of why more metrics than accuracy should be considered… but let’s leave that discussion for another day.

Click through for several techniques you can use to balance out classes, with a focus on image classification. Undersampling is almost always a no-go for me, though I am much fonder of the other techniques.

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Multi-Class Classification in PyTorch

Published 2023-02-03 by Kevin Feasel

Adrian Tam does some iris categorizing:

Now you need to have a model that can take the input and predict the output, ideally in the form of one-hot vectors. There is no science behind the design of a perfect neural network model. But you know one thing, it has to take in a vector of 4 features and output a vector of 3 values. The 4 features corresponds to what you have in the dataset. The 3-value output is because we know the one-hot vector has 3 elements. Anything can be in between, and those are known as the “hidden layers” since they are neither input nor output.

Click through for the full tutorial.

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Flink 1.16.1 Release

Published 2023-02-03 by Kevin Feasel

Martijn Visser announces Apache Flink version 1.16.1:

The Apache Flink Community is pleased to announce the first bug fix release of the Flink 1.16 series.

This release includes 84 bug fixes, vulnerability fixes, and minor improvements for Flink 1.16. Below you will find a list of all bugfixes and improvements (excluding improvements to the build infrastructure and build stability). For a complete list of all changes see: JIRA.

We highly recommend all users upgrade to Flink 1.16.1.

Read on for the release notes, including links to all of the closed tickets.

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Azure Load Testing Now GA

Published 2023-02-03 by Kevin Feasel

Darryl Taft provides an overview of a now generally available service:

Moreover, Azure Load Testing collects detailed resource metrics to help you identify performance bottlenecks across your Azure application components. You can automate regression testing by running load tests as part of your CI/CD workflow.

Azure Load Testing also creates monitoring data using the Azure Monitor service, including application insights and container insights, to capture details from the Azure services.

It’s available in 11 regions, including the best region of all (East US) and the second-best region of all (East US 2).

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