Dashboard Complexity

Rationale

The VIZYUL™ Dashboard Complexity best practice rule fires when a dashboard has more than four worksheets on it.

Insight

Consider this, dashboards with many worksheets allow authors to include many dimensions and measures on the same dashboard.  Obviously, the benefit of this design choice is centralized content.  At first glance this may not seem like a problematic design choice, however, here are a few things to consider before settling on this approach.

Performance Implications

  1. Each worksheet and quick filter added to a dashboard triggers a tableau query against the data source equal to the number of objects on the dashboard.
  2. Each time tableau has to query a data source, doesn’t matter whether its a live or extract connection, there is a load time cost.
  3. The more worksheets on a dashboard, the longer it will take tableau to render the view (deliver the visualization to your viewers).  This is determined by the number of queries tableau has to execute and the time cost for each query.
  4. Tableau 8.3 or prior executes each query synchronously, which means each query must finish before the next run is executed.

How Tableau Improves Performance

  1. Caching – Basically this means storing the aggregated data you need so additional queries aren’t necessary.  This only applies to the dimensions and measures used on specific worksheets to optimize performance.
  2. Parallel Queries – In tableau version 9 tableau performs queries in parallel.  Basically this means non-cached queries are executed at the same time for different data sources at the same time, cutting down on the time it takes to render the view.

 

Action

  • Consider reducing the number of worksheets on a dashboard.
  • Consider the order in which worksheets and quick filters are added to the dashboard.  The order has a direct impact on tableau’s ability to leverage caching to improve the performance of your dashboard.  See the first resource below for more info.

Additional Resources

  • http://tableaulove.tumblr.com/post/98949091175/decrease-tableau-dashboard-render-time-with
  • http://kb.tableau.com/articles/knowledgebase/database-query-performance
  • Video (requires free tableau login to view) – http://www.tableau.com/learn/tutorials/on-demand/tableau-server-authoring-performance
  • http://kb.tableau.com/articles/knowledgebase/optimizing-tableau-server-performance
  • http://www.tableau.com/about/blog/2015/1/90-preview-query-performance-improvements-36406