Hi All,
I know we are told to set cardinality while developing universes. Is it always necessary? Is yes, why?
ajq
anushajq (BOB member since 2005-02-22)
Yes, you should always set cardinalities on your joins.
Why? Because there are features (like loop detection / resolution) that don’t work without it. I would also consider it a “best practice” to do this. If you don’t understand the data well enough to set cardinalities, then you probably don’t understand it will enough to be able to identify and resolve fan or chasm traps.
Dave Rathbun 
(BOB member since 2002-06-06)
This topic has been discussed in past. May be this will help you.
https://bobj-board.org/t/84179
Rakesh_K 
(BOB member since 2007-12-11)