Removing a child instance from a parent child list. - non L2 Caching

Question

I have a parent Entity
Parent
int id
String name
@onetomany
List <Child> list
and a child Entity
Child
int id
String name
First, let me say, I have L2 cache turned off.
So lets say I have a parent record with three children and I want to remove child 2. I have found if you remove the child only in the EM then when you select the parent again, it shows the child still being there even though the child has been removed from the db. I liked only having to remove the child because its only one instance to pass and remove over the web. But with that said, how do I remove the entity our of the parents Children list so it no longer shows up in the front end in the list? I cant use the selected index in the front end because I sort the data.
Or is it better to save the state of Parent too? But if so, what if Parents Children is hundreds of records. Thats alot of overhead for one record to be deleted. Could use some help here. Thanks in advance.

Answer 1

You should always maintain bi-directional relationships. You need to remove the child from the parent.
Since you are not caching, if you acquire a new EntityManager after commit, the parent's child will be gone.
If you refresh the parent in the same EntityManager after commit, then it will be gone.
If the collection is really big, then consider not mapping it, just query for it if you need it. There is no point having a relationship that is too big to read.
Note that if you use weaving, and a List, then remove() will not trigger the collection to instantiate in EclipseLink (nor add, but contains or size will).