A Fine Slice Of SQL Server
Meagan Longoria continues her discussion of design concepts with pre-attentive attributes:
Four preattentive visual properties have been defined:
Color (intensity, hue)
Form (orientation, line length, line width, size, shape, curvature, enclosure, added marks)
Spatial Positioning (2-D position)
Movement
Good information, and then Meagan ties it to Power BI.
Comments closedReza Rad announces a new feature of Power BI Helper:
I’m excited to share the news with you that we have added a new feature in Power BI Helper; Expression Tree. Expression Tree will expand the tree of expression for a Measure or calculated column, you can see what other measures are used to create this expression, and where other measures, calculated columns, or even normal columns are located (in which table). This feature is in addition to previous two features of this tool which were; Showing tables and fields used in visualization pages of a Power BI Report, and ability to search for a column or table that used in visualization pages of a report. In this post, I’ll explain how this new feature works.
Read on for the explanation. I can see this being quite useful.
Comments closedDaniil Maslyuk shows how to perform conditional formatting on a line chart in Power BI:
Have you ever wished you could change the line colour depending on the overall trend? For example, if your sales increase over time, the line is green; if there is a decline, then the line is red. While this functionality is not yet natively available in Power BI Desktop, it does not mean this cannot be done! In this article, I am going to show you how to achieve this effect.
Read on to see how he does it.
Comments closedMeagan Longoria explains the concept of cognitive load and how it relates to building reports:
Our first design concept is cognitive load, which comes from cognitive psychology and instructional design. Cognitive Load Theory says that when we present our audience with information, we are asking them to use brain power to process it. That brain power (aka working memory) is limited, so we need to be intentional about the information we present to them.
In order to commit information to memory and be able to recall it later, that information must go through sensory memory and working memory and then be encoded into long-term memory.
This concept drives a lot of good advice in dashboard and report design, particularly that if it does not directly help a person learn the important information you are trying to convey, it’s not worth having on the report or dashboard.
Comments closedIn many cases, SSAS works efficiently with default settings right out of the box. However, when you have large databases, substantial number of concurrent users, insufficient resources on your server, or when best practices are not followed during SSAS database design, you can run into performance bottlenecks and problems. In these scenarios, you need to know what to measure and how to measure them, what’s normal for your environment (benchmark), and you need to have some amount of historical measurements to be able to see the events that lead to a certain bad performance/failure point. Once you have this data, you can improve your server’s performance by addressing the problem(s).
This is a tour de force of an article, absolutely worth reading if you plan on dealing with Analysis Services at some point. Even if you don’t build your own tool, you’ll learn a lot about what drives SSAS performance and what indicates that there might be a problem.
Comments closedGogula Aryalingam shows us a neat trick in Power BI:
Enthusiastic as we were, one of the hardest nuts to crack, though it seemed so simple during requirements gathering, was to perform a distinct count of a dimension based on a filtered measure on a couple of the reports. To sketch it up with some context; you have products, several more dimensions, and a whole lot of measures including one called Fulfillment (which was a calculation based on a couple of measures from two separate tables). The requirement was to get a count of all those products (that were of course filtered by other slicers on the Power BI report) wherever Fulfillment was less than 100%, i.e. the number of products that had not reached their targets.
Simple as the requirements seemed, the hardest part in getting it done, was the limited knowledge in DAX, specifically, knowing which function to use. We first tried building the data model itself, but our choice in DAX formulae, and the number of records we had (50 million+) soon saw us running out of memory in seconds on a 28GB box; Not too good, given the rest of the model didn’t even utilize more than half the memory.
Click through for the answer.
Comments closedRob Collie shows how to incorporate jitter in Power BI scatter charts:
Now, sometimes you may WANT multiple rows to combine into one dot, but in this particular case, I want to see each row of my source data as its own dot.
When adding a new calculated column, there are LOTS of ways to uniquely “stamp” each row with its own distinct value. I could do this in DAX, but it would require concatenating/combining enough columns together (in this case, probably [Game #], [Qtr], and [Time], since no two rows can “happen” at the same time in the same game.
But for other reasons that you will see shortly, I need the unique identifier to be a number, and I don’t want to go through the contortions of converting text values to numeric, plus as you can see, the data is incomplete in the [Time] column (lots of blanks).
There’s a lot here, and the end result is a great addition to your Power BI toolbelt. But as I’m reading Rob’s post, I’m thinking about how much easier it is to do some of this with ggplot2.
Comments closedDevin Knight continues his Power BI custom visuals series:
In this module you will learn how to use the Image Timeline Custom Visual. The Image Timeline is a great way to display data in order across a timeline. If you have images of your data you can also display those images on the timeline.
This is a fun one, and Devin provides a great example of putting the pieces together on an educational dashboard.
Comments closedWolfgang Strasser points out a new feature in Power BI Desktop:
In some cases, sources for Direct Query models are either large (and therefore need some time to bring back the data) or slow (which could maybe be improved by some database tuning :-)).
Before the Nov2017 release, every change in a filter or slicer led to an immediate round trip to the data source which made some of those reports … let’s call it .. not perfect in the context of user experience.
Beginning with the Nov2017 release some options for Query Reduction has been introduced.
Click through for an example of how to use Query Reduction on direct query models.
Comments closed
I have written while ago, about how to implement a dynamic row level security in Power BI. This post is an addition to that post. I’ve had a lot of inquiries that; “What If I want users to see their own data, and the Manager to see everything?”, or “How to add Manager or Director Level access to the dynamic row level security?” This post will answer this question. In this post, you will learn a scenario that you can implement a dynamic row level security. In this scenario, everyone will see their own data, but the manager will see everything. If you want to learn more about Power BI, read Power BI book from Rookie to Rock Star.
Read on to see one method of solving this dilemma.
Comments closed