2 Replies Latest reply on Mar 22, 2016 12:13 AM by pulkit jain

    Data source filter applies before join in tableau or after join

    pulkit jain

      I have 2 tables say A an B and I want to apply cross join in Tableau.

      Table a is having some data  and table b have employee data.

      I want to do a cross join between these two but want to reduce data of table b to a single row based on username() who logged in.

      (Provided table b have single row for single user).


      Currently I am using a conditional data source filter on table b as username()= user but not sure whether it will perform the join first and then apply the data source filter OR data source filter on table b first and then join it.


      Its important to know for performance issues as with sample data its working fast but original data will be 1000 times more and I cant test with real data.


      Any information regarding this will be very helpful.