benchmark activerecord loading associations

gistfile1.rb

require 'benchmark'

puts "loading..."
APP_PATH = File.expand_path('../../config/application',  __FILE__)
require File.expand_path('../../config/boot',  __FILE__)
require File.expand_path('../../config/environment',  __FILE__)

puts "running..."

selections = ['source_id', 'campaign', 'sum(cost) as cost']
conditions = {source_name: 'google'}
groupings  = ['source_id', 'campaign']
included   = ['source']

n = 10
Benchmark.bm(17) do |x|
  x.report("no preload:") do 
    n.times do 
      MarketingCost.select(selections).where(conditions).group(groupings).to_a.map { |c| c.source }
    end
  end
  
  x.report("with cache:") do 
    n.times do 
      ActiveRecord::Base.connection.cache do
        costs = MarketingCost.select(selections).where(conditions).group(groupings).to_a.map { |c| c.source }
      end
    end
  end
  
  x.report("includes:") do
    n.times do 
      MarketingCost.select(selections).where(conditions).group(groupings).includes(included).to_a.map { |c| c.source }
    end
  end
  
  x.report("includes w/cache:") do
    n.times do 
      ActiveRecord::Base.connection.cache do
        MarketingCost.select(selections).where(conditions).group(groupings).includes(included).to_a.map { |c| c.source }
      end
    end
  end
  
  x.report("preload:") do
    n.times do 
      MarketingCost.select(selections).where(conditions).group(groupings).preload(included).to_a.map { |c| c.source }
    end
  end
  
  x.report("eager_load:") do
    n.times do 
      MarketingCost.select(selections).where(conditions).group(groupings).eager_load(included).to_a.map { |c| c.source }
    end
  end
  
  x.report("joins:") do
    n.times do 
      MarketingCost.select(selections).where(conditions).group(groupings).joins(*included.map { |i| i.to_sym }).to_a.map { |c| c.source }
    end
  end
  
  x.report("joins w/cache:") do
    n.times do 
      ActiveRecord::Base.connection.cache do
        MarketingCost.select(selections).where(conditions).group(groupings).joins(*included.map { |i| i.to_sym }).to_a.map { |c| c.source }
      end
    end
  end
end

#                         user     system      total        real
# no preload:         8.340000   0.350000   8.690000 (  9.664360)
# with cache:         6.420000   0.110000   6.530000 (  6.630513)
# includes:          14.690000   0.050000  14.740000 ( 14.912824)
# includes w/cache:  14.110000   0.030000  14.140000 ( 14.193161)
# preload:           14.050000   0.030000  14.080000 ( 14.134771)
# eager_load:         2.650000   0.030000   2.680000 (  2.693203)
# joins:              8.520000   0.350000   8.870000 ( 10.112449)
# joins w/cache:      6.280000   0.100000   6.380000 (  6.414173)