8 Replies Latest reply on Dec 19, 2017 12:09 PM by philip.watkinson

    Tableau 10 Cross-database join issues (calculated fields & DataType)

    Antoine Des Aulniers Favreau



      For one of my project, I had to connect a decent amount of data from Oracle to multiples excel sheets.

      Since Blending queries would eventually take way too much memory, after a couple minutes, the workbook would take 10gb + and slow down everything/crash my pc, I had to find another solution than Blending.


      I was hope Tableau 10 cross-datasource joins would help but I'm running into multiples issues, and 2 that I want to highlight:

      1) It seems I cannot create a join on a calculated field. Is it really the case or am I missing something?


      2) I know Cross-datasource join do not support join on different data type, but changing datatype of my Oracle source does not seems to register.


      For example, I'm trying to link Effective Date (Oracle) to Date (Excel). By default, Effective Date is a Date&Time data type while Date is a Time Data type. However, even if I change Effective Date data type to Date, i still get an error message on my joins, as you can see below.

      I even extracted the whole table to make sure that the data type "register" in Tableau, to no avail.



      So even if Tableau is showing me in the datasource menu and data pane that effective date is DATE, I still get the error message, and cannot create my own Table within Table 10.


      Thank you,