mildmojo

# Here's a contrived example of a LEFT JOIN using ARel. This is an example of
# the mechanics, not a real-world use case.

# NOTE: In the gist comments, @ozydingo linked their general-purpose ActiveRecord
# extension that works for any named association. That's what I really wanted!
# Go use that! Go: https://gist.github.com/ozydingo/70de96ad57ab69003446

# == DEFINITIONS
# - A Taxi is a car for hire. A taxi has_many :passengers.
# - A Passenger records one person riding in one taxi one time. It belongs_to :taxi.

IanVaughan

#!/usr/bin/env bash

uninstall() {
  list=`gem list --no-versions`
  for gem in $list; do
    gem uninstall $gem -aIx
  done
  gem list
  gem install bundler
}

jboner

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

njvitto

#Deploy and rollback on Heroku in staging and production
task :deploy_staging => ['deploy:set_staging_app', 'deploy:push', 'deploy:restart', 'deploy:tag']
task :deploy_production => ['deploy:set_production_app', 'deploy:push', 'deploy:restart', 'deploy:tag']

namespace :deploy do
  PRODUCTION_APP = 'YOUR_PRODUCTION_APP_NAME_ON_HEROKU'
  STAGING_APP = 'YOUR_STAGING_APP_NAME_ON_HEROKU'

  task :staging_migrations => [:set_staging_app, :push, :off, :migrate, :restart, :on, :tag]
  task :staging_rollback => [:set_staging_app, :off, :push_previous, :restart, :on]