3 Replies Latest reply on Oct 27, 2015 3:33 AM by Jane Crofts

    Out of memory when refreshing extract

    Med Ouza

      Hi all,


      I've spent days trying to understand this.


      I have a big workbook with a quite a lot of (+-20) calculated field to do some basic grouping with IF/ELSE statement.


      Recently I wanted to add additional calculated field to do another grouping the same way I used to do this BUT whenever i'm trying to do a refresh of the extract (under Mysql) - the memory goes crazy and its failed.

      The thing weird is that those calculated field I've added are working smoothly and fine with the existing extract but can't anymore refresh it!


      To be concrete, I'm doing the grouping with calculated field like this -

      I have a field - codename and I'll do like "level1group" calculated field group :

      IF codename='brussel' then 'belgium'

      ELSEIF codename='antwerp' then 'belgium'

      ELSIF codename='paris' then 'france'


      then a "level-2" calculated field group

      IF [level1group]='belgium' then 'europe'

      ELSEIF [level1group]='paris' then 'europe'


      Thanks for your help !

        • 1. Re: Out of memory when refreshing extract
          Jane Crofts

          Hi Med,


          have you tried using groups for the "level-2" grouping, rather than a calculated field? 


          My guess is that the data is going into a spin with calculations trying to calculate based on calculations before the calculations have been calculated (yes - that very poor sentence was intentional!)...


          You also said that you're drawing the data from mysql?  Could you push any of the 'codename' calcs back into the original query so that your tableau datasource receives a concrete 'codename' which could then be grouped?


          Keep in mind that string based calcs are very resource intensive - so the more you can do to simplify these (and use other techniques such as 'groups' or 'sets') - the better your performance will be.


          I hope this helps!

          1 of 1 people found this helpful
          • 2. Re: Out of memory when refreshing extract
            Med Ouza



            Yes indeed your guess (which what I was thinking also) is correct. I played a bit with the groups in the strings calcs and it was fine but yeah, it eats sometimes huge ressources.

            My example was pretty simple but I'm building financial statement who looks like this :

            PrtScr capture_22.jpg

            I was defining level like this with simple string based calcs with IF/ELSE statement for this but I guess I found the limitation on performance side for this... The groups features can work also but may be less flexible, I'll try to replace some in order to maintain the workbook effiency !



            • 3. Re: Out of memory when refreshing extract
              Jane Crofts

              You’re welcome!  I’m glad we were able to get to a workable solution!


              Would you please mark my response as ‘correct’ or ‘helped’?  Many thanks!!