How to solve following situation:

PHP Code:
entity --class ~.ImageWrapper
field string 
--fieldName url --notNull
entity 
--class ~.Album
field set 
--fieldName images --type ~.ImageWrapper 
This way the "Create Album" form has a Listbox containing every single ImageWrapper entry. So each time I create a new Album instance, I have to read all images from the database.

If I used a reference to Album in the ImageWrapper class instead, I'd end up with a listbox containing all Albums in the "Create Thumbnail" form.

This approach does not work with a lot of data.

So what is the most elegant way to model this?