[athenot]

Either way, it's serialization: object serialization or JSON serialization.

However, independently of how the data is represented (JSON or one of the many binary formats), the issue is to only encode/decode what you actually care about. From the little I understand about java object serialization, there's a lot of extra stuff that gets encoded, which may not be needed at all for the application at hand.

For an example of efficient serialization techniques, take a look at some of the MPEG formats (the older ones are easier to grok). They have a neat way of representing what is needed and dealing with optional data.