Second benchmark for AR queries

benchmark2.rb

require 'active_support'
require 'active_record'
require 'benchmark/ips'

ActiveRecord::Base.establish_connection adapter: 'sqlite3', database: ':memory:'
ActiveRecord::Base.connection.instance_eval do
  create_table(:customers) { |c| c.string :name }
end

class Customer < ActiveRecord::Base; end

name = 'Luciano Sousa'
Customer.create! name: name

Benchmark.ips do |x|
  x.report('where_first')  { Customer.where(name: name).first }
  x.report('find_by_name') { Customer.find_by_name(name)      }
  x.report('find_by')      { Customer.find_by(name: name)     }
  x.compare!
end

$ ruby benchmark2.rb
Calculating -------------------------------------
where_first      332.000  i/100ms
find_by_name 922.000  i/100ms
find_by            930.000  i/100ms
-------------------------------------------------
where_first      3.416k (±10.2%) i/s -     16.932k
find_by_name 9.194k (± 8.0%)  i/s -     46.100k
find_by            9.345k (±10.7%) i/s -     46.500k

Comparison:
find_by:             9345.0 i/s
find_by_name:  9193.6 i/s - 1.02x slower
where_first:       3415.8 i/s - 2.74x slower