The N-ary relationships, have been traditionally a source of
confusion and still are. One important source of confusion is that the
term cardinality in a relationship has several interpretations, two of
them being very popular. But none of the two approaches, nor the two
together, allow us to express all the possible cardinality patterns. The
transformations from all the possible relationships to database schemas
have never been described by the existing literature. Using the 14
ternary patterns as example, we discuss these transformations
particularly the transformations from the patterns ignored in the
literature.Postprint (published version
