2 Replies Latest reply on Oct 9, 2013 3:44 AM by Kent Graziano

    new user, many dimensions and facts question


      I am just wondering how others layout their model when they have 30 dimensions and 5 fact tables.


      For example:

      fact 1 uses 10 dimensions.

      fact 2 uses 5 dimensions

      fact 3 uses 3 dimensions


      Would you use 1 relational model and add all of the entities to the model? As you can imagine, the model gets to be quite busy. I've tried to add multiple relational models, but then I end up duplicating entities and worry about changes being made in only one place for the entity. Is a subview on the relational model per fact table a good way to go?


      I'm open to any suggestions.




        • 1. Re: new user, many dimensions and facts question

          Hello Brian,


          In fact you can use both options you mentioned:

          1- you use one relational model and split it up on in several subviews. In your case a fact per subview could be a good solution.

          2- you use one relational model per fact. To prevent duplicate entities among relational models, you can link tables instead of making copies. You can make a link of a table by dragging the table into the subview of another relational model.


          You can of course mix both models by using multiple relational models and have in a relational model multiple views.



          • 2. Re: new user, many dimensions and facts question
            Kent Graziano

            I use one sub-view per fact. I also do the overall model in the main diagram for the overview. That is helpful if you have conformed (shared) dimensions.


            I would only use a separate relational model to represent different versions of the same logical model 0 such as dimensional vs 3NF views of the data or Oracle vs DB2 or SQL Server.