1 Reply Latest reply on Sep 3, 2016 10:31 AM by Yuriy Fal

    Speed up map dashboard rendering time

    Luke B

      MY OBJECTIVE/DASHBOARD SUMMARY: reduce the rendering time of this map dashboard that accepts two user-supplied values. The dashboard allows a user to specify a 'site' and see how many 'providers' fall within a distance radius specified by the user.

      Each 'site' and 'provider' have a lat/long. A calculated field calculates the point to point distance between the 'site' and 'provider'. The user-specified distance value is compared to this value for the filtering.


      DATA STRUCTURE: Ostensibly, the dataset is a Cross Join/Cartesian product of my 'provider' and 'site' lists. In other words, there is a record for every possible combination of 'site' and 'provider. The resulting dataset is about 8MB/150k records and results in a slow rendering time. This dataset is a little smaller than the real one. 'Sites' can be distinguished from 'providers' because they have a 'program ID' = 0. 

      There ends up being a lot of uncessary data in here because a user is only looking at one 'site' at a time, and most likely there will only be <30 'programs' that fall within their specified distance. I was able to achieve a fast rendering in our local environment by connecting the dashboard to a database, instead of an Excel file, and using a paramterized Cross Join query to reduce the dashboard's data set to only the records for the specified 'site'. But I cannot post to Tableau Public/create a packaged workbook with the Database connection. That pseudo query looks like:


      SELECT s.SITE, p.*


      WHERE s.SITE = [p_siteID]


      My hope for this problem is that there is a way to connect the Dashboard to two separate Excel files - one containing my site list and one containing my provider list - and that I could achieve a result similar to my set-up with the direct database connection (i.e., a paramterized cross join between the two Excel sheets)


      Thoughts on how I may achieve this? Is there a totally different solution I should be pursuing for improving this dashboard?


      EDIT: Added Tableau Public viz


        • 1. Re: Speed up map dashboard rendering time
          Yuriy Fal

          Hi Luke,


          I don't see any performance issues with your view.

          Do you have Performance Recording workbook(s)

          comparing your Excel-based and DBMS-based approaches?


          As far as I could see, most of the time is spent on

          rendering background map tiles, and it's the thing

          you couldn't optimize so much (may be switching

          to Mapbox would be helpful, may be not).


          I doubt if using two different datasources could help.