Questions about Cross-store support

[martypitt]

I'm evaluating a cross-store deign for a current project, where we're considering using both MySQL and MongoDB.

Having read the [documentation][1], I'm left with a few questions:


The doucmentation speaks of cross-store support for a JPA Entity which contains a property that is persisted as a `@Document`. Does support exist going the other way? Ie., Can I have a MongoDB document as the parent, which contains a reference to a JPA Entity (or a collection of entities)?

Eg:

@Document
public class Product
{
@Entity?
private Manufacturer manufacturer;

@CollectionOfEntities?
private List<Review> reviews
}


Similarly, is there support for persisting a JPA Entity which contains a collection of Docuemnts?

eg:

@Entity
public class Shop
{
@Id
private Long id;
// Product is a MongoDB @Document
private List<Product> products;
}

Is this supported?

Given that cross-store persistence is so new, are there any resources for design best practices, or pitfalls to avoid?

[1]: http://static.springsource.org/sprin...go.cross.store

[martypitt]

Just bumping this.

Also, this question is cross-posted to Stack Overflow, which now has a bounty running.

http://stackoverflow.com/questions/9...or-collections