1 Reply Latest reply on Apr 19, 2017 7:15 AM by Shawn Wallwork

    LOD clarification

    Esther Twain

      Hi community,

       

      Regarding LODs, I've read this paragraph:

       

      "With include keyword calculation will always either have same or finer level of detail than the sheet which requires aggregation to match sheet’s level of detail. For fixed it can be coarser or finer depending on the calculation and dimensions in the sheet. Since the need to aggregate or not depends on what dimensions are in sheet, it can change anytime. Having an aggregation defined is safe since if and when aggregation is needed, you already told Tableau how to do it. Because of all this, calculations with custom level of detail are always wrapped in an aggregate when in the sheet unless they’re used as dimensions. If no aggregation is happening (e.g. calculation has the same level of detail as the sheet or is coarser hence getting replicated instead) then changing the aggregation will not make any difference in the results. You will notice that when you drag a pill that is an exclude calculation, Tableau will default to ATTR (as opposed to SUM or AVG as you’re used to see with measures) to hint that what’s happening isn’t aggregation."

       

      Can someone please enlighten me about this paragraph, in particular about the bold part? How can you explain it using your own words and examples?

      Has this something to do with the fact that by using FIXED there is no adaptation at whatever new dimension we bring into or out of the view?In another words, is this an advantage or disadvantage of using Fixed LOD?

       

      Thank you!

       

      Esther

        • 1. Re: LOD clarification
          Shawn Wallwork

          Esther Twain wrote:

           

          Hi community,

           

          Has this something to do with the fact that by using FIXED there is no adaptation at whatever new dimension we bring into or out of the view? In other words, is this an advantage or disadvantage of using Fixed LOD?

           

          Yes to your first question. The answer to your second question is: It depends on what you're trying to do. If you want this behavior, then it's an advantage; otherwise it's a disadvantage. In my mind Fixed LODs have a couple of uses:

           

               -- Change the order of execution so the Fixed LOD is not affected by pills on the filter shelf (unless you add 'Context' to them). This makes calcs like % of Total much easier, avoiding the need to use Table Calculations.

           

               -- Aggregate an aggregate

           

          There are lots of other uses, which you can find here: Top 15 LOD Expressions | Tableau Software

           

          Hope this helps.

           

          --Shawn