4 Replies Latest reply on Sep 25, 2013 3:00 PM by Robert Morton

    <TableauMode>

    Scott Bortz

      What is the value of incorporating <TableauMode> when using Teradata query banding?  Documentation says it will evaluate as Connect or Analytical, but what's the significance?  Is there any performance improvement in the Teradata engine when this is passed down to the database during a live connection?

        • 1. Re: <TableauMode>
          Robert Morton

          Hi Scott,

           

          The information Tableau sends to Teradata via query bands allows DBAs to define rules which help with prioritizing and queuing the subsequent queries issued by Tableau. A useful configuration may route 'Connect' mode queries to a low-latency, high-priority queue, while queries issued in 'Analytical' mode may need longer timeouts and normal prioritization. However a Tableau-specific query band configuration doesn't exist by default on Teradata, so you will not see any effect from those query bands on your performance when building or loading visualizations.

           

          Does this help?

          Robert

          • 2. Re: <TableauMode>
            Scott Bortz

            Absolutely, that's in line with my thoughts.  If it's useful to set up rules with the DBA the <TableauMode> provides a way of classifying the different query modes for them to differentiate, but there's no benefit out of the box.  Thanks!

            • 3. Re: Re: <TableauMode>
              Scott Bortz

              Hi Robert

               

              A follow-up question for you on this topic.  I'm finding that I have not set up query banding in my Tableau data source, yet these queries are still present in the Teradata log.  Is there any way to turn this off in Tableau?  An example is below.  I assume if I don't specify my own custom query band, then Tableau takes the liberty to send the default query band below.  Or perhaps Teradata can require such information with a setting on its end.  Any insight is appreciated.

               

              SET QUERY_BAND='App=Tableau;Edition=Desktop;Mode=Connect;User=scott.bortz;Version=7.0;' FOR SESSION

               

              The reason I ask if this is a controllable setting is that some of my workbooks have as many as 8 data sources and opening workbooks takes quite long.  In each instance, Tableau is validating the querying, which is understandable, but at the end fires a bunch of query band statements which seem unnecessary and can take an additional 20+ seconds.  I'm trying to reduce this delay.  See my profile of statement types from when I open my workbook (descending order).

               

              STATEMENT_TYPE

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              Right now, we are not taking advantage of query banding in Teradata for tuning purposes, though we intend to explore this.  In the interim, just trying to learn what is controllable on the Tableau end and how we can improve upon this.

               

              Thanks!

              • 4. Re: <TableauMode>
                Robert Morton

                Hi Scott,

                 

                If you wish to suppress all query banding, consider placing a single space character or semicolon in the Teradata connection, under the 'Advanced...' dialog that supports query band definitions.

                 

                As for the performance problems of having so many queries, please consider reporting these problems to Tableau Support (support@tableausoftware.com) so they may work with you to collect log files and determine if there's a fundamental problem with how we handle query banding.

                 

                -Robert