Hi, Fabio
The Join should be performed on a minimal resultset.
Fig1:
If the Union increases the number of rows then its bad for the join above it. The Join could take more time to process.
Fig2.
Though multiple joins are performed, they all should be processed in parallel.
I think Fig2 should provide a better performance.
Of course Visual Plan will provide a deeper insight.
A deeper analysis can be done on the performance if we can dig inside the Analytic Views as well.
--Shreepad