Default Cardinality

[Former Member]

Hi Friends,

I have referred to below thread however what I am really interested to know is what is the default cardinality considered if we do no set for a join.

Regards,

Tejas

[Former Member]

Why would you not set the cardinality of a join?

Set the cardinalities for joins as you create them. You cannot detect contexts without them and they add further documentation to the universe - other universe designers will understand your design more easily.

As for a default cardinality, there's no such thing. Default is to set the correct cardinality for that particular join. For joining a dimension to a fact table, default is 1 dimension to many facts.

Be clear though, the cardinalities do not directly affect the SQL generated; they only have an impact on the SQL indirectly - that is, when they are used to detect contexts. It is the contexts themselves that have an impact on SQL generated.

[former_member4998]

Hi…

If you join two tables with Cardinality with UnKnow or one-to-one (1,1) or one-to-many (1,N) or  many-to-one (N,1) or  many-to-many (N,N))  will get the same results.

Cardinality plays role while considering context  (one-to-one (1,1) or one-to-many (1,N)) .

So cardinality (Default, 1:1,1:N,N:1,N:N) gives the same results.

Please find the below doc for more info.