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Sun, 2007-Jun-17

On ODBMS versus O/R mapping

Debate: ODBMS sometimes a better alternative to O/R Mapping?

Objects see databases as memento and object-graph storage. Databases see objects as data exposed in table rows. RDF databases see objects data exposed in schema-constrained graphs. The private of one is the public of the other. The benefits of each conflict with the design goals of the other.

Perhaps REST is the middle ground that everyone can agree on. Objects interface easily using REST. They simply structure their mementos as standard document types. Now their state can easily be stored and retrieved. Databases interface easily using REST. They just map data to data. So the data in an object and the data in a database don't necessarily have precisely-matched schemas. They just map to the same set of document types and these document types define the O-R mapping. The document type pool can evolve over time based on Web and REST principles, meaning that tugs from one side of the interface don't necessarily pull the other side in exactly the same direction.

If O-R mapping is the Vietnam of computer science, perhaps we should stop mapping between our object and our relational components. Perhaps we should start interfacing between them, instead.