bcnf - Bcnf lossless join

Question

Are all relations in bcnf provide lossless join or can any relation be bcnf but not lossless join at the same tiem?

Is there a way to show that a relation that is not in bcnf but NOT lossless join.

Answer 1

在某些模式中，不分解为 3.5NF 是保留依赖性的。参见(Tsou 1982)的例子。