5 Replies Latest reply on Jan 4, 2019 2:03 PM by Kumar Geddam

    Level of Detail Expression

    Kumar Geddam

      Hi Friends

       

      Mostly LOD expressions are used to compute the values at datasource level and visualization level. I am familiar to use the LOD expression at the visualization level, but not sure to use LOD expression at the datasource level. Though their is constraints for supporting LOD at datasource levels, Oracle DB supports it as per the below link. Can somebody help me in using the LOD at the Datasource level?

       

      Data Source Constraints for Level of Detail Expressions - Tableau

       

      Thank You

      Kumar Mahesh Geddam

        • 1. Re: Level of Detail Expression
          Vikram Gokhale

          As far as I know there is one type of implementation of LODs. Now referring to the link you have provided, unless I am missing something, LODs are implemented using advanced functionality provided by data sources (DBMS, RDBMS or 100s of others) which is made available by more recent versions of these data sources. In the earlier versions of those, certain features were not available which are used by Tableau to implement LOD expressions successfully. That is why it mentions "For some data sources, only more recent versions support level of detail expressions. Some data sources do not support level of detail expressions at all."

          • 2. Re: Level of Detail Expression
            Kumar Geddam

            Hi Vikram

             

            I understood your point, thats the reason i have included the link for reference.

             

            We are using oracle as a datasource and using 10.2 Tableau version which supports the LOD as per the link.

             

            Now my question is how to use LOD Expression at the Datasource Level which is Oracle.

             

            Thank You

            Kumar Mahesh G

            • 3. Re: Level of Detail Expression
              Michael Gillespie

              Kumar, you are misinterpreting what that means.

               

              "Datasource level" in this context means "does the underlying/root data source (Oracle, SQL Server, Excel, etc.) ALLOW us to use a Level of Detail expression in our workbooks?".

               

              It does not indicate a difference between an LOD in a workbook and an LOD in a datasource.

               

              Does that help?

              • 4. Re: Level of Detail Expression
                Vikram Gokhale

                Kumar, there is only one implementation of LOD and that is within Tableau environment. FIXED LODs are executed much before INCLUDE & EXCLUDE. You can refer to the order of execution of diff. objects in Tableau here

                As Micheal has pointed out "Datasource Level" is referring to diff. versions of data sources (Oracle, SQL Server, MS Access, Excel, AWS sources... ). Hope this helps ...

                • 5. Re: Level of Detail Expression
                  Kumar Geddam

                  Hi Michael

                   

                  Actually i am confused as per the first statement in the below link.

                   

                  Level of Detail expressions (also known as LOD expressions) allow you to compute values at the data source level and the visualization level.

                   

                  Level of Detail Expressions - Tableau

                   

                  Regards

                  Kumar Mahesh Geddam