If multiple columns from different tables are having the same name, does Qlikview automatically join them? If yes, how does it take care of circular joins etc. ?
Yes.But if you have more than one common column Qlikview will generate synthetic tables.
this is fine until unless you have any issue interns of performance or understanding of data model.
Because of synthetic keys you never get wrong data.
use below url in the attached txt file to understand circular reference and how it is different from synthetic keys.
Circular reference will give wrong data if data is coming from loosely coupled tables.
also have look at below ppt.it is really helpful.