01_performance.rb

require 'mysql2'
require 'parallel'


start = Time.now
puts "#{start} start"
# (1...10000).each do |i|
Parallel.each(1..10000) do |i|
  client = Mysql2::Client.new(host: ENV['DB_HOST'],
                              username: ENV['DB_USER'],
                              password: ENV['DB_PASSWORD'],
                              database: ENV['DB_NAME']
                             )
  client.query "drop database if exists test_#{i}"
  client.query "create database if not exists test_#{i}"
  client.query "drop table if exists test_#{i}.users"
  client.query "create table if not exists test_#{i}.users (id int primary key,login_id varchar(100), keycode int(3), name varchar(2000), create_at datetime)"
  client.query "create index idx_keycode on test_#{i}.users (keycode) "
  client.close
  puts "execute test_#{i} database"
end
# results = client.query('select * from test')

end_time = Time.now
puts "#{Time.now} finished. spend time #{end_time - start}sec."

Gemfile

# frozen_string_literal: true

source "https://rubygems.org"

git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }

gem 'mysql2'
gem 'parallel'