find_each inner works.

example.rb

# find_each loses order of previous sorted relations
# under the hook it users some primary key ordering
# a workaround to perform iterations in batches is

batch_size = 100
ordered_ids = Model.ordered.pluck(:id)

ordered_ids.each_slice(batch_size) do |slice|
  HeavyWork.call(slice)
end

# in cases where you don't need to process in batches you can go with
# the normal each method

records = Model.ordered

records.each { "..." }