A Fine Slice Of SQL Server
Chris Webb has a public service announcement:
A very quick performance tip: do you have users consuming Power BI reports with Internet Explorer 11 and an older Windows OS like Windows 8.1 or Windows 7? If so, their reports are likely to be slower[…]
Click through to see why they’re slower and what you can do about it. Other than upgrade to Windows 10 or use a different browser.
Comments closedPhil Seamark explains what the KEEPFILTERS() function does in DAX:
If you ever spend time looking at DAX generated by the Power BI Desktop Performance Analyser, you may notice a function called KEEPFILTERS appear from time to time. It’s not a function I find myself using often, so I thought I’d do a bit of digging to find out what it does and when it might be useful.
Read on to learn exactly what it does.
Comments closedCedric Charlier shows off some of the benefit of Power Query with a fairly complicated set of rules:
At the beginning, some of us thought that it would be easy to fix these issues by returning to the data quality team and ask them to fix these issues but it was not so easy. Identifing the rules needing a fix would be huge task (the CSV files are not created if the test is successful, maling it impossible to address this issue in one run and other impediments). I took the decision to go over this issue with the implementation of the following heuristic:
– if the CSV has a column DateTime then we’ll use it
– if the header is empty or no column is named DateTime then use the first column
– if the content of the selected column is not a date then try to parse it as the inner content of a JSON element.
Read on to see how.
Comments closedWhen cleaning dirty data, you might have used the Trim-function (Text.TrimStart or Text.TrimEnd) to delete leading or trailing whitespace from your strings. However, did you know that you could use these functions as well to delete any other characters as well from the start or end of a string? Trimming text with custom characters is pretty straightforward:
Interesting that it does not take a regular expression but rather a list of characters.
Comments closedPatrick LeBlanc has a video for us:
Are you not sure if you are hitting your Power BI Aggregations? Patrick shows you some tools you can use to verify if they are being used.
Click through for the video.
Comments closedWhy is this important? When you’re tuning the performance of a Power BI report the first thing to do is to look at the performance of the individual DAX queries run and make them run as fast as possible. However when a Power BI report is rendered any one query is likely to be run at the same time as several other queries run for the same report, and this will have an impact on its performance. How much of an impact there is will depend on how many queries need to be run and the number of back-end v-cores available on your Premium capacity, or the number of QPUs available on your Azure Analysis Services instance if you’re using a Live connection to AAS. The more v-cores/QPUs you have available, the more of the work needed for a query that can be run in parallel; you can see a table listing the number of v-cores for each Premium SKU here, and the number of QPUs for each Azure Analysis Services SKU here. As a result of this if you have reports with a large number of visuals that generate slow DAX queries, scaling up your Power BI Premium capacity or AAS instance may improve overall report performance. Reducing the number of visuals on your report and/or reducing the number of visuals needed to display the same information will also reduce the number of queries that need to be run and therefore improve overall performance.
Read on for the demo.
Comments closedRyan Wade shows us how to use a pre-built sentiment analysis model with Power BI:
As of this writing, there are two pre-trained models available: one for sentiment analysis and another for image classification. This example focuses on sentiment analysis.
Both of these installations are freely available to the on-prem version of SQL Server 2017 and later. For more information on how to install these on your instance, reference this article for SQL Server Machine Learning Services and this article for pre-trained models.
Click through for step-by-step instructions.
Comments closedJames Serra takes us through different ways to secure your Power BI dashboards and reports:
Row-Level Security: With Row-level security (RLS) you are given the ability to publish a single report to your users but expose the data differently to each person. So instead of creating multiple copies of the same report in order to limit the data, you can just create one report that will only show the data the logged in user is allowed to see. This is done with filters, which restrict data access at the row level, and you define filters within roles. For example, creating a role called “United States” that filters the data in a table where the Region = “United States”. You then add members (user, security group, or distribution list) who can only see data for the United States to the “United States” role (the assignment of members can only be done within the Power BI Service). If a user should not have access to a report, then just don’t include that person in any of the roles for that report, so they would always see a blank report.
Click through for several more options and links to additional resources.
Comments closedReza Rad has fun with dynamic binning in Power BI:
In the previous article/video, I explained how to create dynamic bins by choosing the count of bins in a slicer in the Power BI report. In this article, I’ll explain, how you can do it the other way around, which is by selecting the size of the bin, you will have bins and buckets dynamically generated.
I like this for its ability to let you select the proper number and size of bins when Power BI is being particularly obstinate about something. In an ideal world, I don’t like this so much as a user-facing feature because we as designers should know the proper number and size of bins.
Comments closedDavid Eldersveld shows how to create a custom Power BI button:
Power BI buttons provide more interactivity in reports, and different states allow unique formatting when users interact with a button. What are the visual icons available when using buttons in Power BI, and is it possible to extend them?
Read on for an example.
Comments closed