Tableau’s data blending feature is great for mashing up data sets from a whole variety of data sources. Want do download local weather data from Weather Underground to see how precipitation affects your coffee sales in Seattle? Sure!
However, blending can be a little tricky to set up to get the appropriate level of detail in the view, especially when you need to blend at one level of granularity and aggregate at another. In this post, I’ll walk you through a technique for doing this in v7, and how version 8 makes this process easier, using an example drawn from my own work that adds a level of complexity because the data is sparse. This makes a great case study for how to integrate different features of Tableau to create the desired view.