Bitstore is a new approach to implementing ontylog and other description logics, built on top of CouchDB, that makes a clean separation between syntactic and semantic concerns. Concepts in ontylog are documents in couchdb, each completely independent of others. Relations between concepts, are maintained as separate graphs in a triple store where documents are identified in the triple store by their unique ids. Schema information about the concepts, roles and their properties are also stored as couch documents. It's hoped that this approach will enable a far more flexible system for building and managing terminologies. By keeping description logic and other inference engines separate from the terminologies, and using more general documents to represent concepts we feel that support for multiple world views and ontology federation will as least be doable in some form.


Bitstore is mostly a prototype effort with two major extensions to couchdb. The first, native full text indexing provides support for searching over documents and is based on ideas from the erlang book. The second, a triple store implementation of ontylog is built on top of a graph database which is using Bitcask for persistence. Ontylog is still the most scalable description logic classifier to date. A secondary goal of this effort is to take scalability up to the next level. We think ontologies with a million concepts should be classifiable in a couple of minutes not hours.



The sources for bitstore can be downloaded here, and the sources for the modified couchdb branch are here. The modifications to couchdb are minor. CouchDB is designed in such a way that additional modules can be loaded by the server by specifying them in a config file. The Bitstore extensions access the CouchDB storage layer and it's hoped, perhaps post 1.0, a server side API for storage access will emerge.



Bitstore is free software(GPL). Most of the dependencies are either licensed under Apache2.0 (couchdb, hovercraft), EPL (erlang), LGPL(Eunit), or other open source licenses, such as the Tumbolia Public License.



[FSF Associate Member]