3 Replies Latest reply on Jun 18, 2013 9:38 AM by Joe Cole

    How can I change Viz "perspective" without using joins that make the extract HUGE?

    Joe Cole

      Hello Tableau Gurus!


      I need help.  I've done a fair bit of searching and don't see a solution to my issue.  I'm keeping my fingers crossed that it's a simple solution and that I'm just not proficient enough in Tableau to figure it out myself .


      I've attached a very simplified example of what I'm trying to do in a much more complicated Viz.  The more complicated Viz also references an Excel spreadsheet with > 250,000 records, which is why I can't use a solution that utilizes joins to blow out the data set.


      The first worksheet in the Excel spreadsheet has records for 5 hospitals (A -> E), each with 5 jobs, and has some attributes (Job Title, Date Posted, Date Removed) for each job.  The second worksheet has every unique combinations of the hospitals on the first worksheet, with the corresponding pre-calculated DISTANCE between the hospitals.


      I've defined a Parameter called "My Location", that contains all of the unique Client ID values for the hospitals.  What I'm trying to do seems fairly straightforward.  When the viewer changes the value of the "My Location" parameter, I need the Viz to correctly report the distance between the hospital on each job posting and the hospital selected in the "My Location" parameter.  Here's how I need the table on Sheet 1 to look:




      Ultimately, I need a global filter on a calculated field on a dashboard that allows a user to filter jobs according to the distance of the jobs from their location (which they can change by selecting a value in the "My Location" parameter).  For instance, the dropdown would have values like "Less than 5 miles, Less than 10 miles, Less than 25 miles, Less than 50 miles, Greater than 50 miles".  And as the user chooses a value in the dropdown, only the jobs that meet the selected Distance criteria would display on the dashboard.


      I know I can do this by joining the data together.  However, that approach results in an extract that has all job postings duplicated once for each hospital, with the "Distance" added as another data field.  Changes to the "My Location" parameter just filters the data so that a single copy of the job postings that has the right value for Distance are displayed on the Viz.  I know this works, however, given the size of my data, this approach just isn't feasible.  That's why I'm trying to figure out how to accomplish the same result with Tableau calculated values, relationships, etc., but without using joins.


      Any help you can provide would be greatly appreciated!