Dynomite Vs Aws Record

Important: These docs are for the outdated Jets 5 versions and below. For the latest Jets docs: docs.rubyonjets.com

AWS::Record is a data mapping abstraction over the AWS SDK for Ruby’s client for Amazon DynamoDB written by AWS themselves. The pro to it is that it’s written officially by AWS. However, it is a lightweight library. It has different goals. It focuses on lower-level things.

Modeling

Aws::Record

class MyModel
  include Aws::Record
  integer_attr :id, hash_key: true
  string_attr  :name, range_key: true
  boolean_attr :active, database_attribute_name: 'is_active_flag'
end

Dynomite:

class User < ApplicationItem
  fields :name, :email, :rank
  field :role, default: "basic"
end

One difference is that AWS Record is included as a module Aws::Record whereas Dynomite classes inherit from ApplicationItem, which inherits from Dynomite::Item. This allows you to add common methods to the base abstract ApplicationItem class.

AWS Record is somewhat verbose syntactically. At of the time of this writing, it’s README says under development and the interface may change.

Migrations

Both have migration abilities.

Aws::Record

cfg = Aws::Record::TableConfig.define do |t|
  t.model_class(MyModel)
  t.read_capacity_units(5)
  t.write_capacity_units(2)
end
cfg.migrate!

Dynomite:

class CreatePosts < Dynomite::Migration
  def up
    update_table :posts do |t|
      t.partition_key :id
      t.add_gsi :title
      # t.provisioned_throughput(
      #   read_capacity_units: 5,
      #   write_capacity_units: 5
      # )
    end
  end
end

With Aws::Record, you need to call the code via a Rake task or something. You need to set it up for your own needs.

Dynomite has a CLI command to run the migrations.

jets dynamodb:migrate

Importantly, it manages the ran migrations state and will only run the migration if it has not already been run in a schema_migrations table.

Saving

Aws::Record

item = MyModel.find(id: 1, name: 'Foo')
item.update(id: 1, name: 'Foo', age: 1)

Dynomite

post = Post.new(title: "post 1")
post.save

post = Post.new
post.title = "post 2"
post.save

post = Post.new do |p|
  p.title = "post 3"
end
post.save

The Aws::Record saving notation is more lightweight. Validations were removed in #17 to reduce the scope of the library. So you do not get Callbacks and Validations.

Batch Operations

Aws::Record

operation = Aws::Record::Batch.read do |db|
  db.find(Lunch, id: 1, name: 'Papaya Salad')
  db.find(Lunch, id: 2, name: 'BLT Sandwich')
  db.find(Dessert, id: 1, name: 'Apple Pie')
end

# BatchRead is enumerable and handles pagination
operation.each { |item| item.id }

Dynomite:

Post.where(category: "cloud").each_page do |page|
  page.each do |post|
    # do something
  end
end

Since Dynomite returns a Relation Lazy Enumerator, it can handle large data because items are only loaded as needed in Pages

Post.where(category: "cloud").each do |post|
  # do something
end

Interestingly, AWS is using batch_get_item and batch_write_item under the hood and is probably more optimal. Dynomite does not currently provide convenience wrapper methods for batch_get_item and batch_write_item. Note: We will review and consider PRs.

Summary

It’s hard to compare the two libraries because Aws::Record and Dynomite are pretty different in scope. Aws::Record is a lightweight layer. Dynomite is an ORM.

In this section: