In case of regular universe all the tables have to be joined. where as in case of Metric universe all the tables need not be joined, there can be isolated tables in universe.
In metric universe object descriptions are parsed. eg:- In universe if we create a measure object (Revenue) with sum function in select clause.and simply including AGGR=SUM in decription, we cannot further aggretae the Revenue measure in EPM while creating the metric. All the aggregate functions will get disabled while metric creation.
What's the major difference between regular universe & metric universe?