I use Mongo with its Java driver and Morphia. I am mapping this class:

```
public class Transaction {

    @Id
    private ObjectId id;
    private String transactionUniqueIdentifier;

}

```

I see in the console that Mongo saves a transaction in a form like `{transactionUniqueIdentifier: "xjeer"}`

Does it mean I should use shorter property names ("uuid" instead of "transactionUniqueIdentifier") to get a smaller database? Or is there a setting in Mongo which would deal with that for me (create shorter names internally...).  

Any pointer would be appreciated, thx.