2 Replies Latest reply on Nov 9, 2016 4:48 AM by Dhanashree Arole

    How Tableau Desktop runs SQL query when using tables

    suresh matta

      I have following question on Tableau desktop product.

      Example:

      • - I have a 3 tables in database where table 1 has 40 columns, table 2 has 50 columns, table 3 has 70 columns.
      • - I join the tables according to my business logic
      • - I check the “Convert to custom SQL” option and get the code which will have look something like this
      • - Select

                (40 columns from table1, 50 columns from table 2, 70 columns from table 3)

              , From tabl2 1, table 2, table 3

               where join etc.,

      Question:

      • - Does Tableau run all the columns and tables whenever it queries data to render data?
      • - Does Tableau run only the columns included in the report whenever it queries data?
      • - If we use hide option on the data source pane, how does it effect performance in LIVE connection (not extract)

       

      I checked that Record performance is not very clear nor the log.txt file to get more details...