2 Replies Latest reply on Feb 14, 2013 8:34 AM by Matt Lieberman

    1 Workbook for Calculations and 1 for Presentation?

    Matt Lieberman

      I created a workbook for one of my company's clients which is filled with a variety of computationally-intensive calculated fields that often require reading text strings. The workbook is comprised of online advertising data and features calculations for ad serving like If [Placement] contains "CPC" then clicks*.04, etc. Unsurprisingly, having a lot of calculated fields, many of which are based on text strings, has had a very negative effect on performance when we present the workbooks to the client on Tableau Server.

       

      The data source for my workbook is an Excel file from my company's database. It features data at the placement level by day. I was wondering whether I could basically relegate my current, slow, Tableau workbook to serving as a calculation workhorse to create a new data source for another workbook to be presented to the client. I would create a crosstab of daily data at the placement level from the calculation workbook and then use that crosstab as the data source for another workbook that would not feature the complex string-based calculations and present the latter workbook to the client. This crosstab would basically replicate the raw data used in the first workbook but also include the results of the complex calculations. Has anyone done something like this before? Does this make sense?

        • 1. Re: 1 Workbook for Calculations and 1 for Presentation?
          Brad Llewellyn

          Matt,

           

          You can create a local extract of your Excel Sheet by Right-Clicking on the Data Source, then choosing "Extract Data."

           

          After you have created a local extract, right-click the data source, then Select "Extract -> Optimize."  This should upload all of your calculated fields into the extract, which would allow you to query them directly instead of recalculating.

           

          Does this help?

           

          Brad Llewellyn

          Associate Consultant

          Mariner, LLC

          Email:     brad.llewellyn@mariner-usa.com

          LinkedIn:  http://www.linkedin.com/pub/brad-llewellyn/4a/80a/73b/

          Blog:      http://breaking-bi.blogspot.com

          • 2. Re: 1 Workbook for Calculations and 1 for Presentation?
            Matt Lieberman

            Hi Brad,

             

            Thanks for the response. I currently am using an extract of the Excel file pulled from the database in the workbook with all of the calculations. As a result, it is already optimized and everything. The idea behind using two workbooks is to keep the workbook for presentations free from having to compute any complicated formulas. So in the example of ad serving I would have some kind of field called "Gross Media Cost" in the calculation workbook that takes the Net Media Cost and adds the Agency Fee, Ad Serving and other calculations to the figure. In the crosstab that would serve as the data source for the presentation workbook I would just include the "Gross Media Cost" column which was calculated in the calculation workbook and thus does not have to be calculated in the presentation workbook.