I'm looking for a document-oriented db with a Ruby API that has SQLite-like properties:
- self-contained,
- serverless,
- zero-configuration.
Are there light alternatives to MongoDB or CouchDB?
Is RDDB a possibility?
If not, what are the best paths to walk then?
It's not ready yet, but embeddable version of CouchDB are on the long term roadmap.
Replication is intended to enable offline applications with CouchDB. If you ended up with very specific needs you could replicate data from couchdb to a local datastructure, store it locally, update it, and push the data back via replication but it would take some code.