Newbie question on cardinality in a data model

Hi,

could somebody please explain why it is so important in a data model to specify the cardinality of a relationship?  From what I understand, if I query a database via SQL the statement I write does not depend on the cardinality (with the exception of outer joins) of a relationship. Yet my reporting tool (Cognos Reportnet) requires me to set the cardinality of each relationship. Why is it necessary, and what happens if I set it wrong? Any help or reference to reading material is greatly appreciated!

Thanks,

Anna Received on Fri Oct 31 2003 - 13:30:14 CST