anti_heap_fragmentation.rb

# put this in config/initializers
class NoopArray < Array
  def <<(e)
    self
  end

  def push(e)
    self
  end

  def concat(a)
    self
  end
end

ActiveRecord::ConnectionAdapters::AbstractAdapter.set_callback(:checkout, :before) do |a|
  cta = :@_current_transaction_records
  a.instance_variable_set(cta, NoopArray.new) unless a.instance_variable_defined?(cta)
end