3 Replies Latest reply on Jun 1, 2016 9:52 PM by Ashish Chaudhari

    Query about Live Connection



      I am a bit confused about how tableau works. So I have a live connection. I am using tableau desktop and I connect to the data source. I am not using any data source filters and I have a lot of data (in Gbs).

      Question 1) Is the data already loaded into tableau when I do this?


      Question 2) If I am setting all my filters (quick filters) to (none), every time I open my view does the entire data get loaded in tableau or does it check the filters and gets the data from data source accordingly? Also if I am publishing this on the server then how does it work for the server then?


      Question 3) Every time I select/un-select something on one of the quick filters, does tableau start immediately querying the data source? Thanks.

        • 1. Re: Query about Live Connection
          Ashish Chaudhari

          Hi Ritika,


          Ans 1) In case of live connection tableau refers the database and pulls out the all records that are required to display on the dashboard. In case of extract it creates its own copy of data in the packaged workbook and fetches the data from the extract (there us no communication between tableau and database that time).


          Ans 2) You can publish the workbook the way you want. If you want to show specific item to be selected (on load), then select that Item and publish it. Every time you launch the dashboard in the tableau server it will show filter set to that particular value. Tableau does checks all the quick filters based on which it fetches data from database or extract.


          Ans 3) Once you change the values in the quick filters it starts querying database but there is an option inside the customize option for filter which provides apply button for filters. This helps in making selection of items from the filter and after clicking on "Apply" it fetches the data from the database.


          I hope this helps and answers your all queries.



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          • 2. Re: Query about Live Connection
            Dmitry Chirkov

            Great answer!


            All I can add is that Tableau almost never deals with "all the data."

            For example, when you ask for "sales per region" all the data that Tableau gets and displays is list of regions and number for each one of those regions. All the number crunching is happening in the database.


            Same with data displayed on filters - Tableau never sees all the data but instead issues query like this: SELECT Region FROM T GROUP BY Region. This query returns all the distinct Region values.



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            • 3. Re: Query about Live Connection
              Ashish Chaudhari

              Hi Dmitry,


              Thanks for adding up to the answer and making it a overall response better.