rkv - Ruby Key Value - an adapter on top of various key-value and column stores


The API is a nested (multidimensional) Hash. This allows effective mapping to both column stores and flat KV stores.

For example, if the Cassandra adapter is used, the first dimension is the column family, the second is the row within the CF and the third is the column within the row.

For flat KV stores, a key hierarchy is used for efficient mapping.


Installing the gem:

gem install rkv


require 'rubygems'
require 'rkv'

store = Rkv.open(:cassandra, { :servers => [''], :keyspace => "Blog" })
# store = Rkv.open(:memory, :recurse => {"Users" => "*"})
# store = Rkv.open(:tokyocabinet, :file => "test.tcb", :recurse => {"Users" => "*"})

users = store["Users"]

user = users["5"]
user["name"] = "Dev Random"
user["role"] = "admin"

puts users["3"].inspect

users.batch do
  users[id1]["name"] = "John Doe"
  users[id2]["name"] = "Jane Doe"

user_rels = client[:UserRelationships]
user_rels[id1]["posts"][Cassandra::UUID.new] = post_id1


Keystores have different features. Operations are mapped to the best of the keystore ability, but some operations may be less efficient or impossible in certain keystores.


RDoc: rdoc.info/projects/devrandom/rkv

See spec/integration/stores_spec.rb for an example program that runs identically on all stores.


Supported KV stores

  • Cassandra

  • Memory

  • TokyoCabinet

Planned KV stores

  • Voldemort

  • Redis

  • Keyspace

  • SQL


  • Store support

  • Performance testing

  • Keystore feature support matrix

  • Object mapper?