jailalawat

1. diff map and pluck
2. how many engine available in mysql.

MyISAM(non transactional), InnoDb(Transactional)

3. transaction and non transaction db

4. What app server we use to deploy the app?

passenger,unicorn, puma

jailalawat

What is Rack?

http://blog.gauravchande.com/what-is-rack-in-ruby-rails

Lets start with a basic browser-server interaction. Say you’re developing an app with Rails (or any other Ruby web framework) and it has a page located at ‘http://localhost:3000/users’ that displays all users. The ‘/users’ request is going to go to your Rails server asking to show all users.

Behind the scenes, this HTTP request that the browser sends looks like this:

// Request by the browser

GET /users HTTP/1.1

jailalawat

Ruby basics

Ruby is a class-based object-oriented programming language. Meaning that every object is an instance of a class, and a class defines the state(variables) and behaviors(methods) of an object. An object is an entity with state and behavior, as defined by its class.

Ruby is a perfect Object Oriented Programming Language. The features of the object-oriented programming language include −

Data Encapsulation

Data Abstraction

Polymorphism

jailalawat

# config valid only for current version of Capistrano
lock '3.6.1'

set :application, 'alphait'
set :repo_url, "git@host/repository.git"

# Default branch is :master
# ask :branch, `git rev-parse --abbrev-ref HEAD`.chomp

# Default deploy_to directory is /var/www/my_app_name