4 Replies Latest reply on Oct 25, 2016 12:53 PM by Joe Oppelt

    Working with multiple data sources

    aparna sarampally



      I have two data sources that have the projects data. One has investment and metrics data that is at the total project level. And the other is master data has the Forecast and actual values for each savings stream in a project. (A project may have multiple savings streams).

      Now, I am creating worksheets independently (No Blending or joining) and adding them on a dashboard. I am using a project name parameter here to filter the data in all the sheets. This worked for me so far, but every time a new project is added I need to update the parameter. This could be an issue.


      Then, I tried to join the data but since the granularity in two data sources is different, the investment and metrics values are coming out huge.

      Next is blending: I blended @them on the project name field. for the worksheets based on Investments I added the project name filter from the master data. This is working at the sheet level. But on the dashboard, I am able to apply the project name filter only to the master data Worksheets. That way the two worksheets that I have created with investments data are not getting updated with filter.


      How do i achieve this?




        • 1. Re: Working with multiple data sources
          Norbert Maijoor

          Hi Aparna,


          Here we go...


          Upfront. Your are mentioning "the other is master data has the Forecast and Actual". Both data sources do have master data (e.g. costcenter, proficenter etc) and both have transaction data (e.g. investment, metrics data, Forecast and Actual.

          You would like to "join" the datasources based on a join or blending by connecting masterdata values which are available in both datasources.

          As an example. Your actual data is stored on the level day and your Forecast data is stored on a month level. By aggregating your actual data from day to month level you are able to join on the right level. So the dimension on which you would like to join should be on the "same level of aggregation"  When you blend be sure the datasource which is less detailed is brought in at first and becomes your "primary" data source.


          Hope above makes a little sense.


          PS you can provide a workbook with data?

          • 2. Re: Working with multiple data sources
            Joe Oppelt

            You have a lot of questions there...


            Let's start with one at a time.


            I have a huge workbook that has 8 different data sources.  Some are forecast data, some historical data, some current data.


            On all my data sources I have a DATA SOURCE FILTER (not a quick filter) that has a formula in the "Condition" tab that looks like this:


            [Managed Segment] = "All" or

            UPPER([ManagedSegment]) = [Managed Segment]


            [Managed Segment] is a parameter that lets the user select one segment (in your case a project name).  I also have a value of "All" in the parameter list.  If the user selects "All", he gets all segments added together.

            [ManagedSegment] (no space) is the field in the data source.


            I have this on each data source, and the [Managed Segment] parameter is displayed on all dashboards, so the user can change segments anywhere in the workbook.

            And yes, if new Segments ever get added, I'll need to add to the parameter in the workbook.


            This has worked out very well for us, and I can blend all the sources together however I need.


            As for blending, you'll have to blend at the same level of granularity.  If you have project-level data in the metrics source and savings-stream data in the master source, you'll have to join at the project level.  You will not be able to display metric data at a savings-stream level.

            • 3. Re: Working with multiple data sources
              aparna sarampally

              Thanks Guys!

              I am using the parameters and it's working out quite well. But whenever a new project is added, updating the parameter manually is the only factor in looking for other options.

              • 4. Re: Working with multiple data sources
                Joe Oppelt

                Right.  You are looking for Dynamic Parameters.  It's on the IDEAS list here:




                It's high on Tableau's radar, but it's not implemented yet.