10 Replies Latest reply on Oct 22, 2013 9:44 AM by Jonathan Drummey

    Performance Question Workbook Attached

    Shawn Wallwork

      To produce a text table that colors selected columns I was forced to use the paired scaffolding Jonathan Drummey pioneered -- 22 pairs! Here are the bits I can show:

       

      Perform-1.pngPerform-3.png

      Perform-2.png

      That's one excel file blended to a MS SQL Server. These are extracts for me to work with. They connect live after I send them back the workbook. Even using these extracts, any change to a filter take 40+ seconds to refresh!

       

      I did a performance recording of making one change in one filter. (see attached). Now I'm trying to figure out what it means and what if anything I can do to improve the performance. Essentially, my question is what is taking so long?

       

      Thanks,

       

      --Shawn

        • 1. Re: Performance Question Workbook Attached
          Matt Lutton

          Holy ****.  I hope they reward you for your efforts! (Sorry, I don't know much about how to interpret the performance recordings--but I wanted to applaud your effort)

           

          If you have maintenance with Tableau, I'd create a case and see what kind of response/advice they can give as well.

          • 2. Re: Performance Question Workbook Attached
            Matt Lutton

            Hey Shawn:  Did you interact with the viz and change filters when you had the performance recording going?  I ask because the queries I see all show .01 seconds.

            • 3. Re: Performance Question Workbook Attached
              Shawn Wallwork

              Matthew, thanks for taking a look. Yes I simply turned on the recorder, clicked a check box to turn off a single individual and then waited. Most everything T does, it does in less than a second, but those eventually add up to real time (at least in this case).

               

              --Shawn

              • 4. Re: Performance Question Workbook Attached
                Jonathan Drummey

                Hi Shawn,

                 

                You didn't post a packaged workbook with some sample data so I'm not able to give you specifics...

                 

                When you're using the multiple axis crosstab and have different levels of detail on the different axes, you can end up having really slow views because Tableau is having to make one or more queries to the database for each Marks Card, (and you've got 44 of them). From looking at the performance recorder, it looks like Tableau issued 924 queries to the data sources. I don't know why it would be that many.

                 

                I can also see a bunch of time spent in computing table calculations, not knowing anything about what those table calcs do I can't say more than they could be slowing things down. I'm very careful about where I use table calcs in my views for that reason, sometimes I end up doing pre-aggregation in the data to avoid the performance hit of table calculations.

                 

                Also, I can see that you're using filters across the blend. I don't have information on performance there, but I can imagine that impacting performance as Tableau has to compute the domains across the two sources and then merge the data together many times over for this particular view.

                 

                You didn't say anything about parameters, if you have any of those you can end up with situations where Tableau isn't able to do much caching of query results, and that can be a bear on performance.

                 

                This might be a case where a lot more of the computation and aggregation is done in the data source to create a source that can be drawn without needing all the separate Marks Cards, Joe Mako is really good at building these.

                 

                Jonathan

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                • 5. Re: Performance Question Workbook Attached
                  Shawn Wallwork

                  Jonathan, thanks for the analysis. Yeah I didn't post a workbook because this is such a bear to build, and trying to dummy up the data would have been difficult. My question really was about the performance workbook Tableau generated and you gave me several avenues to explore. Unfortunately the one I think would work best, pre-aggregation in the data source is not available to us. They only have data entry and connection rights, they can not build new tables/queries, etc.

                   

                  Thanks for the insights.

                   

                  --Shawn

                  • 6. Re: Performance Question Workbook Attached
                    Matt Lutton

                    You didn't post a packaged workbook with some sample data so I'm not able to give you specifics...

                     

                    I think that was a bit of a zinger... 

                    • 7. Re: Performance Question Workbook Attached
                      Shawn Wallwork

                      I would agree, expect it's Jonathan. His motives are always pure.

                       

                      --Shawn

                      • 8. Re: Performance Question Workbook Attached
                        Jonathan Drummey

                        Ha!

                         

                        I was slightly tongue in cheek as I wrote that first sentence, I figured

                        Shawn would get the joke.

                         

                         

                        On Thu, Oct 17, 2013 at 4:24 PM, Shawn Wallwork <

                        • 9. Re: Performance Question Workbook Attached
                          Shawn Wallwork

                          Update: Just built the workbook over using Measure Names/Values (so eliminating the color columns). Performance went from 40+ seconds to less than 2 seconds. Sure hope they can live without their colored cells, because it sure gives Tableau bad rep with them.

                           

                          --Shawn

                          • 10. Re: Performance Question Workbook Attached
                            Jonathan Drummey

                            Let us know how it goes!