benchmark activerecord mem / ips find_in_batches

bm_ar_find_in_batches_strategy.rb

require 'benchmark'
require 'benchmark/ips'
require 'benchmark/memory'

def select
  Member.select(:id).find_in_batches(batch_size: 10) do |ids|
    puts ids.map(&:id).join(',')
  end
end

def pluck
  Member.find_in_batches(batch_size: 10) do |ids|
    puts ids.pluck(:id).join(',')
  end
end

Member.uncached do
  # bm elapsed time
  Benchmark.bmbm do |x|
    x.report('select') { send :select }
    x.report('pluck') { send :pluck }
  end
  
  Benchmark.memory do |x|
    x.report('select') { send :select }
    x.report('pluck') { send :pluck }
    x.compare!
  end
  
  Benchmark.ips do |x|
    x.report('select') { send :select }
    x.report('pluck') { send :pluck }
    x.compare!
  end
end

Comparison:
select: 273040 allocated
pluck: 641345 allocated - 2.35x more

Comparison:
select: 115.4 i/s
pluck: 71.8 i/s - 1.61x (± 0.00) slower