11 Replies Latest reply on Jul 3, 2018 11:07 AM by nancy.finman

    Tableau Prep Creates Duplicate Records

    nancy.finman

      I have an Excel spreadsheet with four tabs (named 2015, 2016, 2017 and 2018) that have exactly the same data structure. Each record has a unique identifier and there are no duplicates in the file. In Tableau Prep (version 2018.1.1), I am unioning the four tabs of the Excel spreadsheet, then performing some basic cleaning actions. See screenshot below.

      Prep Image.PNG

      When I run the output, Prep creates a lot of duplicate rows (instead of 293,687 rows, it creates 403,623). It creates duplicates from all four of the Excel tabs, but it doesn't duplicate every record.

       

      Any ideas why Prep is duplicating records?