postgresql-cube

activerecord-postgresql-cube

Adds support to ActiveRecord for the PostgreSQL cube data type.

Installation

Add this line to your application's Gemfile:

gem 'postgresql-cube'

And then execute:

$ bundle

Or install it yourself as:

$ gem install postgresql-cube

Usage

Make sure you have the cube extension enabled on your database, then add and index a column with a cube type:

enable_extension "cube"
add_column :things, :features, :cube
add_index :things, :features, using: "gist"

Define optional accessor methods:

class Thing < ActiveRecord::Base
  cube_attributes :features, :fluffiness, :crunchiness, :hotness, :dryness
end

# These are equivalent:
Thing.new(features: [1.0, 0.0, 0.5, 0.2])
Thing.new(fluffiness: 1.0, crunchiness: 0.0, hotness: 0.5, dryness: 0.2)

Query ordered by cube distance to find similar results.

# Seed with some random values:
100.times { Thing.create(features: Array.new(4) { rand }) }

# Query directly:
my_favorite_thing = Thing.by_cube_distance(:features, [1.0, 0.0, 0.5, 0.2]).first
# => #<Thing id: 39, features: [0.832089176888876, 0.192166292526192, 0.56526526018018, 0.0925453162946783]>
my_favorite_thing.distance # => 0.284478455665301

# Or by distance from an existing record:
recommended_thing = my_favorite_thing.similar_by_cube_distance(:features).first
# => #<Thing id: 691, features: [0.61796879992257, 0.249908423662009, 0.593267501286819, 0.0877211312590144]>

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/CandyFet/postgres-cube.

License

The gem is available as open source under the terms of the MIT License.