“Diffing” objects from a relational database

Question

Our win32 application assembles objects from the data in a number of tables in a MySQL relational database. Of such an object, multiple revisions are stored in the database.

Answer 1

This isn't really an answer to the question you asked rather an attempt to re-imagine the problem. Would you consider altering your database and object model to store the aggregate root and a series of deltas? That is, model and store RevisionSets that are collections of Revisions; a Revision is an entity property paired with a value. In a sense this is internalizing the revision structure into your architecture that the other posters are suggesting that you bolt-on to what you already have via "logs".

It's trivial to display the aggregate from the deltas, and even easier to display the deltas as a change history. The fact that you are using a rich client with state and local memory makes this even more compelling. You could very easily display "all the changes since date xxxx" without revisiting the database.

Credit for the basic idea goes to Greg Young and his work with financial data streams, but it is imminently applicable to your problem.