1 Reply Latest reply on Dec 11, 2014 4:27 PM by Minh Vu

    Are calculations that use parameters workbook specific?

    Scott Bortz

      As part of my Tableau solution, we are leveraging data sources published to Tableau Server to (1) build workbooks and publish them to Tableau Server for consumption and (2) to be used by power users with Tableau Desktop to build ad-hoc workbooks/visualizations.  We are purposefully publishing our data source (a live proxy connection and not a data extract) to the Tableau Data Server to centralize the definition of calculations and ensure data consistency.  I have parameters included in my data source along with parameter-dependent calculations.  For example, a parameter to select value or volume and a calculation to aggregate value or volume based on the parameter value.

       

      When I publish the data source to Tableau Server there is no error.  I can also successfully open a new workbook in Tableau Desktop and connect to Tableau Server and the published data source.  However, when i try to use incorporate the parameter based calculations within a viz, Tableau returns the following error:  Invalid field formula due to limitations in the data source.  Class ExpressionException.  Alternatively, I can show/hide the parameter control without any trouble. 

       

      My question is why can I publish a parameter and/or parameter based calculation as part of a Tableau data source if I cannot re-use them later?  Also, are parameters and/or their dependent calculations specific to workbooks definitions and not applicable to data sources published to the data server?

       

      I have validated that I can re-write my calculations as part of a workbook definition that leverages the underlying data source published to the data server, however if I could centralize all components for self-service that would be great.

       

      Thanks in advance!

        • 1. Re: Are calculations that use parameters workbook specific?
          Minh Vu

          Hi Scott,

           

          We're having similar difficulty with our implement of a single source of truth (published data source).

           

          We've discovered parameters in calculations are be replaced/swapped with random parameter, thus breaking the calculation. This is only noticeable if the swapped parameter is of a different data type, e.g. interger being replaced with a string parameter.

           

          For now, we are publishing data source without parameter and set. Sets/Parameters are created at the workbook level.

          However my main concern is Tableau also messing with my calculated fields?

           

          Have you had any update from technical support?