9 Replies Latest reply on Mar 2, 2017 12:16 PM by Norbert Maijoor

    Tableau Extracts and HANA

    Craig G

      I have been using Tableau and HANA for some time, and our data set is finally growing so large the we hit memory allocation errors trying to create an extract from HANA. Therefore, my goal is to reduce the amount of data coming back out of HANA. To do so, can anyone offer clarification on how each of the following effect the SQL query back to HANA:

       

      • HANA Variables
      • Extract Filters
      • Data Source Filters

       

       

      My belief is that

       

      • HANA Variables
        • Reduce the actual amount of information the querry returns thus minimizing the impact on the HANA servers. This would help resolve memory errors, but not all fields are available as variables (atleast in my case).
      • Extract Filters
        • Do not effect the amount of information the querry returns, but filters all the data returned according to filters to create a smaller extract. This servers to improve extract performance by reducing size, but has no impact on the query itselt.
      • Data Source Filters
        • Applied after extract creation and do not influence the query or the extract. These filters simply limit the data returned to the user from the query.

       

      Can anyone please confirm?

       

      My other option is a custom SQL to reduce the number of columns coming back from HANA to strip out columns I do not need, but I have had issues in the past doing so with stable performance.