Voice of the DBA

Category: Editorial

  • Do you use DAX?

    It’s not that often that I see many posts about DAX. Despite the Data Analysis Expressions being used in Power BI, it seems that relatively few people call this out in their work. Chris Webb writes about it often, and this week is no exception. There’s also a short piece on time series from Philip Seamark and another one on optimizing expression from Marco Russo.

    DAX came out of the Analysis Services world and was the way that Microsoft expected people to analyze data in PowerPivot. That never quite became as popular as Microsoft hoped, but the expressions were folded into Excel and still heavily used in SSAS, but it’s really become the way that you can assemble amazing reports in Power BI. If you’re looking to get started, you might check out the Guy in a Cube, Adam Saxton, and his videos on DAX.

    DAX isn’t a native part of Excel, despite the fact that many of the functions are similar or even have the same name. You can use these expressions in the PowerPivot tab in Excel, which you can easily enable. Once you’ve done this, then the power of complex analysis using DAX is available for you.

    Should you learn DAX? That depends. If you need to build reports, or your users are asking for help with more complex analysis, then this might be a skill that helps your career. Your users will appreciate the way in which they can view data with more complex time series and statistical functions available. This seems especially valuable when looking at data across time, like comparing previous periods to current ones.

    As I look around, there are seemingly endless ways in which you can express your creativity with DAX to build more interesting reports. Some of these techniques are useful, some just fun (or perhaps silly), but a change of pace or a new view can help users become more engaged in your reports. They can be fun to build as well.

    Just remember that ultimately you need to use DAX to solve problems and generate insights. Whether you use Power BI, SSAS, or just PowerPivot, don’t build complex reports just because you can. Make sure you understand how the functions enable you to analyze data and the meanings behind their results.

    If you’re looking to get started, we have a great Stairway Series on DAX that can help you, in addition to watching the Database Weekly newsletter for new resources every week.

    Steve Jones

  • Republish: Release Wednesday

    In the UK getting ready for SQL in the City, so Release Wednesday being republished.

  • Republish: State v Migrations

    Back in the UK, so a republish of State v Migrations

  • More Query Tuning?

    This is probably a topic near and dear to the hearts of Grant, Brent, Paul #2 (White), and plenty other more well known speakers in the #sqlfamily community that often present on the topic of writing more efficient code. They do a fantastic job and if you get the chance to see any of these three, take it.

    Recently I saw someone on Twitter ask for more query tuning sessions at SQL Saturday and larger conferences. These seem to be very popular sessions, usually well very attended. Despite this, I don’t see a lot of these sessions compared to the popularity. I sometimes wonder if this is because relatively few speakers want to tackle complex challenges? Or maybe many don’t feel confident portraying themselves as experts in this subject? Is query tuning 101, or even 201, boring and less interesting for speakers?

    I don’t know, and I’ve avoided the topic myself. Part of this is to not conflict with friends, but also it’s a complex topic to try and cover. Despite that, I keep thinking that some more basic concepts would be welcome by many that attend SQL Saturday events. I expect that a there could probably be some sort of performance or tuning talk every hour at a conference and plenty of people would attend. That makes me think I ought to do a tuning session of some sort, just to help ensure this topis is covered more often.

    Picking a mix of topics and levels is often a difficult task for many organizers. As this year’s Summit sessions were released, I’ve seen a number of speakers bemoan that their favorite topic has few, often just one or two, talks scheduled. I think this is somewhat inevitable as new technologies get folded into the Microsoft Data Platform. I know that many of us are excited about one thing, the item that we use most often, or that we’d like to use more. I think the addition of Python is great, but it’s a small part of the platform, it’s new, and I don’t know how many other people want to use it. The same thing could be said for containers, for Query Store, and more.

    Building a schedule for a conference is about making choices and decisions that give a variety of topics, but also include some depth and detail in those areas that are popular. If you’re attending (or attended) a conference this year, the Summit, SQL Bits, a SQL Saturday, etc., what do you want to see on the program? Should there be more performance tuning sessions or do you like a wide variety of topics that let you choose what might suit you?

    Steve Jones

    The Voice of the DBA Podcast

    Listen to the MP3 Audio ( 3.9MB) podcast or subscribe to the feed at iTunes and Libsyn.