rdf-mongo :: MongoDB storage adapter for RDF.rb

This is an RDF.rb storage adapter for MongoDB.

Gem Version Build Status

Versioning and backwards compatibility

Moving forward, the versioning will reflect the RDF.rb version number for which all rdf-specs are passing.

It should also be noted that prior to 1.0, there are no guarantees of backwards compatibility for data stored using previous versions of the gem. This is to make optimizing the schema for MongoDB easy.


You'll need the 'mongo', 'rdf', 'rdf-spec', and 'rspec' libraries. The easiest way to install these is via RubyGems.

$ sudo gem install mongo rdf rdf-spec rspec rdf-mongo

Implementation Notes

RDF Statements are stored as individual documents within MONGO using the following BSON:

  "s":  RDF::Value
  "st": one of :u or :n
  "p":  RDF::URI
  "pt": must be :n
  "o"   RDF::Value
  "ot"  one of :u, :n, :l, :ll, or :lt
  "ol"  Language symbol or RDF::URI
  "c"   RDF::Value or false
  "ct": one of :u, :n, :l, :ll, :lt or :default

An alternative that may be examined at a later point would be to use a representation based on RDF/JSON, or JSON-LD. This would save documents based on a common subject with one more more predicates having one or more types.


Please post questions or feedback to the W3C-ruby-rdf mailing list.


Thank you


This repository uses Git Flow to mange development and release activity. All submissions must be on a feature branch based on the develop branch to ease staging and integration.

  • Do your best to adhere to the existing coding conventions and idioms.
  • Don't use hard tabs, and don't leave trailing whitespace on any line.
  • Do document every method you add using YARD annotations. Read the tutorial or just look at the existing code for examples.
  • Don't touch the .gemspec, VERSION or AUTHORS files. If you need to change them, do so on your private branch only.
  • Do feel free to add yourself to the CREDITS file and the corresponding list in the the README. Alphabetical order applies.
  • Do note that in order for us to merge any non-trivial changes (as a rule of thumb, additions larger than about 15 lines of code), we need an explicit public domain dedication on record from you, which you will be asked to agree to on the first commit to a repo within the organization. Note that the agreement applies to all repos in the Ruby RDF organization.


MIT License