I can use Rails find_each method like :
User.find_each(:batch_size => 10000) do |user| ------ end With find_each method is there any way to get the index of the array ? like :
User.find_each(:batch_size => 10000).with_index do |user, index| ------ end As an update to this question. Active Record 4.1.4 has added support for find_each.with_index as pointed in the documentation.
User.find_each(:batch_size => 1000).with_index do |user, index| user.call_method(index) end 
batch_size defaults to 1000 so if that suits your needs you can just use User.find_each.with_index. api.rubyonrails.org/v4.2.5/classes/ActiveRecord/…Update: As of Rails 4.1.4 this is possible. See this answer for more. Example:
User.find_each(:batch_size => 1000).with_index do |user, index| user.call_method(index) end As you can see from the method definition, this is not possible.
def find_each(options = {}) find_in_batches(options) do |records| records.each { |record| yield record } end end In order to accomplish what you want to do, you need to either create your own modified version of the method
class User def find_each(options = {}) find_in_batches(options) do |records| records.each_with_index { |record| yield record, index } end end end User.find_each(:batch_size => 10000) do |user, index| ------ end or use an instance variable.
index = 0 User.find_each(:batch_size => 10000) do |user| # ... index += 1 end There is no other default solution as shown by the method implementation.
def self.find_each(options = {}) find_in_batches(options) do |records| records.each_with_index { |record, index| yield record, index } end end Now its working.. Thanks...repeating the index after each batch sizes!! No use of the index now. So I used a variable to get the indexes with find_each method.
Your question is already implemented in the Rails master branch. To get this, it requires using Rails edge, as this has not been merged into any release as of yet. See this merged pull request: https://github.com/rails/rails/pull/10992.
So add this to your Gemfile:
gem 'rails', github: 'rails/rails' This will allow you to run the code you described:
User.find_each(batch_size: 10000).with_index do |user, index| puts "UserID: #{user.id.to_s} has index ##{index.to_s}" end Granted, running on the edge release is risky, so don't do this in production. But look at the pull request to see the small amount of code added to get this working. You can monkey patch until it is merged into a Rails release.
Just use an local variable:
index = 0 User.find_each(:batch_size => 10000) do |user| ------ index += 1 end You can get all users and send them through a block along with their corresponding index as follows.
User.all.each_with_index do |user, index| puts "email is " + "#{user.email}" + " and user index is " + "#{index}" end 