Rails ActiveRecord SQL Caching vs Cache to Hash catalog benchmark

db_benchmark.rb

class DBBencmark
  require 'benchmark'

  @@n = 10000
  @@test_langs = ['en', 'et']

  def self.with_cache
    catalog = {
      langs:  Language.all.index_by(&:code),
      topics: Topic.all.index_by(&:name)
    }

    @@n.times.each do
      {
        topic_id: catalog[:topics][''].id,
        lang1_id: catalog[:langs][@@test_langs.sample(1).first].id,
        lang2_id: catalog[:langs][@@test_langs.sample(1).first].id
      }
    end

  end

  def self.without_cache
    @@n.times.each do
      {
        topic_id: Topic.where(name: '').first.id,
        lang1_id: Language.find_by(code: @@test_langs.sample(1).first).id,
        lang2_id: Language.find_by(code: @@test_langs.sample(1).first).id
      }
    end
  end

  def self.perform
    Benchmark.bmbm do |x|
      x.report('cache')     { with_cache }
      x.report('no cache')  { without_cache }
    end
  end


end

Rails_ActiveRecord_SQL_caching_bench.md

Results

Caching with ruby hash is about 1000 times faster than per iteration request to DB without Rails ActiveRecord SQL caching and about 200 times faster than per iteration request with SQL caching.

Excellent!!!
I want to know this result.