There is this concept called User Access Filter which you can read about implementing here
In your case, there is no difference it will cause even if it is left joined with a fact table.
Hope this helps.
Thanks for your response.
But I have a issue here. I went through these blogs and found out that these will require a user mapping maintenance at the tabeau front as soon as a new user is added.
Is it possible to find a solution otherwise?
I got the solution from one of the above blogs now.
But, now the question is:
Does the tableau creates a join first and then apply the filter or the filter is applied first and then the join is applied and data if fetched?
In the other case, I suspect that it may blow up the extract if there are large number of users.