```ruby
require 'active_record'

ActiveRecord::Base.establish_connection(:adapter => 'sqlite3', :database => ':memory:')
ActiveRecord::Base.logger = Delayed::Worker.logger
ActiveRecord::Migration.verbose = false

ActiveRecord::Schema.define do

  create_table :delayed_jobs, :force => true do |table|
    table.integer  :priority, :default => 0
    table.integer  :attempts, :default => 0
    table.text     :handler
    table.string   :last_error
    table.datetime :run_at
    table.datetime :locked_at
    table.string   :locked_by
    table.datetime :failed_at
    table.timestamps
  end

  create_table :stories, :force => true do |table|
    table.string :text
  end

end

# Purely useful for test cases...
class Story < ActiveRecord::Base
  def tell; text; end       
  def whatever(n, _); tell*n; end
  
  handle_asynchronously :whatever
end
```

Add index to AR spec setup
user
```ruby
require 'active_record'

ActiveRecord::Base.establish_connection(:adapter => 'sqlite3', :database => ':memory:')
ActiveRecord::Base.logger = Delayed::Worker.logger
ActiveRecord::Migration.verbose = false

ActiveRecord::Schema.define do
  create_table :delayed_jobs, :force => true do |table|
    table.integer  :priority, :default => 0
    table.integer  :attempts, :default => 0
    table.text     :handler
    table.text     :last_error
    table.datetime :run_at
    table.datetime :locked_at
    table.datetime :failed_at
    table.string   :locked_by
    table.timestamps
  end

  add_index :delayed_jobs, [:priority, :run_at], :name => 'delayed_jobs_priority'

  create_table :stories, :force => true do |table|
    table.string :text
  end
end

# Purely useful for test cases...
class Story < ActiveRecord::Base
  def tell; text; end       
  def whatever(n, _); tell*n; end
  
  handle_asynchronously :whatever
end
```
assistant