Memory profiling method comparing eager_load VS preload aproaches

compare_ram.rb

require 'memory_profiler'
require 'terminal-table'

def compare_ram(scope, base_collection_size, nesting)
  ids = scope.ids
  ids_sample = ids.sample(base_collection_size) # it should be the same id for both tests, since we comparing memory consumption

  # just to keep from memory profiler objects oblivion, and get retain numbers correctly
  el, pr = []
  preload = MemoryProfiler.report do
    pr = scope.where(id: ids_sample).preload(nesting).load
  end

  eager_load = MemoryProfiler.report do
    el = scope.where(id: ids_sample).eager_load(nesting).load
  end

  rows = {preload:, eager_load:}.to_a
  rows.sort_by!{ |(_,profile)|  profile.total_retained_memsize }
  # [ [name, profile] , []]
  smlst = rows[0].last
  rows.map! do |(name, profile)|
        [
          name,
          "#{profile.total_retained_memsize.to_fs(:human_size)}"\
          "(objects: #{profile.total_retained}, ratio: #{(profile.total_retained_memsize.to_f/smlst.total_retained_memsize).floor(2)} )",
         "#{profile.total_allocated_memsize.to_fs(:human_size)}"\
         "(objects: #{profile.total_allocated}, ratio: #{(profile.total_allocated_memsize.to_f/smlst.total_allocated_memsize).floor(2)} )"
        ]
     end.map!(&:flatten)

  puts Terminal::Table.new(:headings => ['Methods', 'Retained', 'Allocated'], :rows => rows)
end