sequel-pg-array.rb

require 'bundler/inline'

gemfile do
  source 'https://rubygems.org'
  gem 'pg', "1.0.0"
  gem 'activerecord', '5.2.0'
  gem 'sequel', '5.8.0'
#   gem 'sequel_pg', :require=>'sequel'
  gem 'memory_profiler'
  gem 'benchmark-ips'
end

require 'active_record'
require 'sequel'
require 'memory_profiler'
require 'benchmark/ips'

system "createdb test_db"

ActiveRecord::Base.establish_connection(
  :adapter => "postgresql",
  :database => "test_db"
)
DB = Sequel.postgres("test_db")
DB.extension :pg_array


at_exit do
  ActiveRecord::Base.remove_connection
  DB.disconnect
  system "dropdb test_db"
end


pg = ActiveRecord::Base.connection.raw_connection

pg.async_exec <<SQL
drop table if exists topics
SQL

pg.async_exec <<SQL
CREATE TABLE topics (
    id integer NOT NULL,
    iary int[],
    sary text[],
    tary timestamp[]
)
SQL

class Topic < ActiveRecord::Base
end


Topic.transaction do
  topic = {
  }
  Topic.columns.each do |c|
    topic[c.name.to_sym] = case [c.type, c.array?]
                           when [:integer, true] then "{#{20.times.to_a.join(",")}}"
                           when [:text, true] then "{#{(65..85).map(&:chr).to_a.join(",")}}"
                           when [:datetime, true] then "{#{(["2018-06-05 12:33:44"] * 10).join(",")}}"
                           else "HELLO WORLD" * 2
                           end
  end

  10.times do |id|
    topic[:id] = id
    Topic.create!(topic)
  end
end

$conn = ActiveRecord::Base.connection.raw_connection


class TopicSequel < Sequel::Model(:topics)
end

def ar_pluck_iary
  Topic.limit(1000).pluck(:iary)
end

def sequel_pluck_iary
  TopicSequel.limit(1000).select_map(:iary)
end

def ar_pluck_sary
  Topic.limit(1000).pluck(:sary)
end

def sequel_pluck_sary
  TopicSequel.limit(1000).select_map(:sary)
end

def ar_pluck_tary
  Topic.limit(1000).pluck(:tary)
end

def sequel_pluck_tary
  TopicSequel.limit(1000).select_map(:tary)
end

def test(method)
  puts
  puts "-"*50
  puts method.to_s
  puts "-"*50
  send method

  MemoryProfiler.report do
    send method
  end.pretty_print(detailed_report: false, retained_strings: false, allocated_strings: false)
end


tests = %i{
  sequel_pluck_iary
  sequel_pluck_sary
  sequel_pluck_tary
  ar_pluck_iary
  ar_pluck_sary
  ar_pluck_tary
}

# tests.each do |t|
#   test t
# end

Benchmark.ips do |b|
  tests.each do |t|
    b.report(t.to_s) do |i|
      while i > 0
        send t
        i -= 1
      end
    end
  end
end

# to run deep analysis run
# MemoryProfiler.report do
#   ar
# end.pretty_print