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mongodbmorphia

Morphia and object graphs

I've yet to use Morphia, but I'm considering it for a current project.

Suppose I have a POJO with a number of @Reference annotations and I ask Morphia to fetch the object graph from the database. If I then make another DAO or DataStore call and ask Morphia to fetch some object that was already instantiated in the first graph, would Morphia return a reference to the already instantiated object or would it create a new instance?

If Morphia returns a new instance of the object each time, does anyone have a recommendation of how to best approach creating a Morphia-backed repository that won't duplicate already-instantiated objects?

Solution

  • As I see it in Morphia, it will re read every reference. This is one of the problems, why I created Morphium. I integrated a caching layer there, so if you read a reference, this one won't be read again (at least, if you search by ID...)