Possible for POJO to have a set of children with only one table?

Question

I have a situation that I'd like to model with Hibernate, but I'm not sure how to proceed.
I've got two objects: Filter and Criterion. Filter has a java.util.Set of Criterion children.
I currently have a schema with two tables: FILTERS and CRITERIA. The FILTERS table has nothing more than a primary key. CRITERIA has a foreign key relationship with FILTERS. I have a FilterDAO that will query the FILTERS table and bring back a Filter object that will use the one-to-many, parent-child relationship between the two tables to populate the Set.
A DBA here has pointed out that the FILTERS table is anemic - it has nothing more than a primary key. She suggested that I eliminate it and go directly against the CRITERIA table to populate that Set.
I'm so used to thinking about these things in terms of primary/foreign key relationships that I'm not seeing how to accomplish this with Hibernate. Is it a mere <set> declaration that populates the child java.util.Set<Criterion>? The WHERE clause would have to include a filter type. Is that where the JOIN has to come? Is the two table schema absolutely necessary, or can I get away without it?
Hibernate allows the object model to be more fine-grained than the schema. The classic example is a PERSON table that has address information it in. I can model this on the object side using Person and Address classes and ask Hibernate to fetch the Address state as a component. Is this the same situation as my Filter and Criterion?
Sorry if I sound confused, or if the question rambles. I guess I don't understand Hibernate well, because any time I get off the beaten path I fall into a hole.
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Answer 1

Well, you're more advanced than me with Hibernate. I'd be very surprised if that were true, DrClap. 8)
I can't even get one-to-many relationships working the
way I'd like, every time I think I have it right
(i.e. just the same as the examples) it gives me some
guff about backreferences not existing.I'm finding Hibernate to be a bit difficult, especially when I don't have control over the schema. Our DBAs don't seem to follow all the "best practices" that Hibernate recommends.
So my advice might not be the best. But if you don't
have the Filters table, but you still need to get all
the Criterions with "filter key" = x, then isn't that
just a Query? Sure, you get the data back as a List,
but you can wrap that in a Set pretty easily.I've gone back to the DBA and concluded that we have to have a FILTERS table (there's a FILTER_TYPE descriptor field that I've added). It's back in, so the 1:m with CRITERIA should work fine.
But it begs the question: Does Hibernate and O/R mapping demand at least one table per object?
If I look in "Hibernate In Action" on page 92, it says "A major objective of the Hibernate project is support for fine grained object models" - more classes than tables. There should be an adjective "persistent" applied to classes in that phrase, because I can have many more classes that are not persisted.
So I take this to mean that the limit is one persistent class per table, but never less. True?
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