I am searching for a document-oriented db having a Ruby API which has SQLite-like qualities:
Exist light options to MongoDB or CouchDB?
Is RDDB possible?
Otherwise, do you know the best pathways just to walk then?
You should use Tokyo, japan Cabinet via it's Ruby API.
It isn't ready yet, but embeddable version of CouchDB take presctiption the long-term roadmap.
Replication is supposed to enable offline programs with CouchDB. Should you wound up with very specific needs you can replicate data from couchdb to some local datastructure, store it in your area, update it, and push the information back via replication however it would try taking some code.
Should you be using Perl, I'd recommend
DBM::Deep, which stores arbitrary data structures on disk, including transactions with commit/rollback, and it is a non-C one-Perl-module install. Does not get lighter than that.
I almost feel you could do this some kind of hack to do this.
Possess a table using sqlite's row ids together with a area for collection title and text blob that might be json code.
Have another table for indexing with fields inside a collection (collection title, area title, area value, document row id).
You could do this some wrapper class to deal with such things as updates and searches. Could be interesting.