Hi all,

In the hibernate 3 ref manual, i came across the following statement

"A unidirectional one-to-many association on a foreign key is a very unusual case, and is not really recommended."

The manula also says

"A unidirectional one-to-many association on a join table is much preferred. Notice that by specifying
unique="true", we have changed the multiplicity from many-to-many to one-to-many."

Can someone pls help me understand why it is not recommended!

Thank you in advance!

With the current implementation of Hibernate, uni-directional one-to-many relationships without a join table result in hibernate executing an insert and an update for the child table.

Insert to set all the properties of the child table
then Update to set the foreign key back to the parent.

This has a really bad performance impact.