1 Reply Latest reply on Sep 8, 2017 12:50 PM by patrick.byrne.0

    Questions on slowness in connecting to teradata SP

    Zixin Li

      I have one Teradata SP whose runtime is within 5s when executing it in Teradata but 30-300s when executing it from Tableau.

      Most of the time, it's stuck at "Loading metadata" and after that when retrieving the data, the retrieved row count seems to be increase by 100 at a time.

      In addition, when edit dashboard, every time when I change the value of a parameter which will affect one calculation field only, it will try to load metadata again which takes 30-60s.

       

      My questions are:

      1. What is Tableau trying to do when "Loading metadata" when connecting to Teradata SP? Any suggestion to improve it?

      2. What is Tableau trying to do when "Loading metadata" when change parameter value? Any suggestion to improve it?

      3. Tableau retrieves result set by 100 rows at a time? Is it configurable, or it's due to other issues e.g. connection speed?

       

      Appreciate your help.

        • 1. Re: Questions on slowness in connecting to teradata SP
          patrick.byrne.0

          Hello Zixin,

           

          Does this occur with all the connections to the Teradata data source or only specific connections?

          A potential solution would be to suppress the calls to the METADATA with a .tdc file.

           

          To leverage a .tdc file follow the below instructions:

           

          Place the .TDC file in one of the following locations:

           

          TABLEAU DESKTOP

          • \My Documents\My Tableau Repository\Datasources

          TABLEAU SERVER

          • C:\ProgramData\Tableau\Tableau Server\data\tabsvc\vizqlserver\Datasources

          OR

          • C:\Program Files (x86)\Tableau\Tableau Server\data\tabsvc\vizqlserver\Datasources

          Tableau Desktop for MAC

          • Documents > My Tableau Repository >Datasources

           

           

          To Resolve the unexpected metadata loading error.

           

          Implement a .tdc file with the following customization.

          <connection-customization class='teradata' enabled='true' version='10.3'>

          <customization name='CAP_ODBC_METADATA_SUPPRESS_SQLFOREIGNKEYS_API' value='yes' />

          </customizations>

          </connection-customization>

           

          You should be aware that if they are refreshing extracts on server they need to have the exact same TDC on server as well.

           

          Cheers