Rails 2.3 : Batch Processing
find_in_batches / find_each
Invoice.find_in_batches(:include => :invoice_lines) do |invoices| export.add_invoices(invoices) end
User.find_each do |user| NewsLetter.weekly_deliver(user) end
Ruby on Rails 2.3 Release Notes - 4.5 Batch Processing
Active Record Query Interface - 1.3 Retrieving Multiple Objects in Batches