Relational databases are not limited to hierarchies. You can create complex graphs if you want. It's all how you model your information. They were created due t

Relational databases are not limited to hierarchies. You can create complex graphs if you want. It's all how you model your information. They were created due to the limitations of hierarchical and network db systems. There was an interesting discussion on Artima ("Software Development Has Stalled") last week that touched on the schema-free idea. One of the participants suggested that computers could use inference to determine data relationships. (In his words, the computer is hypothetical and would need to be infinitely fast.) Presumably by computer he meant some agent doing machine learning on top of the "infinitely fast" hardware. If your idea is along the inference line, then it would be interesting to see how far inference could go. However, if you mean to simply encode relationships into each program (or into a library), then it's just a re-invention of a schema.