4 Replies Latest reply on Nov 11, 2011 12:53 PM by Ian Waring

    Over Enthusiastic Extract Generation?

    Ian Waring

      I have one extract derived from a 380,000+ row Excel spreadsheet, and have several models that use this extract in my copy of Tableau Desktop Professional. However, when I upgrade Tableau and use the extract, things seem to be fine - until I then open one of my older models. At which point, I get the below error message and then get invited to regenerate the extract.



      Unable to connect to the file "C:\Users\iwaring\Documents\My Tableau Repository\Datasources\SALESHISTORY (SBUHISTORY2005-9WITHESAS.XLSM).TDE". Check that the file exists and that you have sufficient access privileges for it.


      The extract still works fine from the other model, so the file is there and access rights fine.


      So, if I use a variety of models, I end up spending considerable time waiting for each to rebuild the extract each time. Bug or feature?

        • 1. Re: Over Enthusiastic Extract Generation?
          James Baker

          So it looks like "old" means pre-6.0, where we switched extract technologies.  I have a few questions: 1) Are you connecting to this TDE as a Firebird connection in your secondary (non-extract-generating) workbooks?  2) What does "use" (in upgraded Tableau) mean?  And I presume "open one of my older models" means you're going back to Tableau 5.X that connects to the same Firebird source.


          I didn't think that simply opening an old workbook would upgrade its extract in-place.  So this does seem odd to me.

          • 2. Re: Over Enthusiastic Extract Generation?
            Ian Waring

            Hi James,


            I have one large spreadsheet (Excel 2007 .xlsm format) and two virtually identical models with several worksheets plus two dashboards each. One model gives complete calendar year sales histories, up to the end of 2010. The other is identical bar a single computed field called YTD, which filters the months from January to the end of the current calendar month - 1. So it gives the current sales trends 2006-2011 showing the January-October numbers for each year, including the current year.


            Both point at the same extract. If I launch one off the thumbnails, it will work fine. If I close it, open the other one in the same way, it will ask to regenerate the extract. Off for a coffee while it does it. Go back to the other one, and it will prompt to regenerate that one.


            The only thing I can think of is that I do save the original excel file on a local drive and a backup version on a network drive, both with identical names. Just wonder if I've inadvertently got the two models remembering the location of the source Excel file in two different places, even though the content is identical. Would that lead to the behaviour I'm seeing?

            • 3. Re: Over Enthusiastic Extract Generation?
              James Baker

              That's right, I just tested it, and you do get a prompt that asks you if you want to regenerate the extract when you open a firebird-based extract.


              So, it sounds like you've upgraded all your Tableau workbooks, and are not still trying to use 5.X also - that simplifies things.  The regeneration prompts you're getting -- hmm... I'm not exactly sure of the details of what's going on.


              I might recommend this: Have an "extract maker" workbook that generates and uses (as an overlaid extract) the extract.  Have your other workbooks simply connect to a Tableau Data Engine file as their data connection -- not even pointing to any Excel file at all.  That way you don't get multiple workbooks each thinking that they *own* the extract.


              Tableau Server 7.0 has some big improvements in the area of data source management.

              • 4. Re: Over Enthusiastic Extract Generation?
                Ian Waring

                Thanks James. Will do that. Greatly appreciated.


                Ian W.