ruby - Rails find_in_batches with locking -

i need process large number of records in batches. , each batch should processed in it's own transaction. there way wrap each batch in transaction , lock records in batch @ same time?

model.scheduled_now.lock.find_in_batches |batch|   model_ids = batch.map(&:id)   model.update_all({status: 'delivering'}, {"id in (?)" , model_ids})    # creates , updates other db records   # , triggers background job   perform_delivery_actions(batch) end 

does select update in example commits transaction after each batch? or need put internal transaction block , lock records manually inside each batch (which means 1 more query)?

the reason don't want put outer transaction block want commit each batch separately, not whole thing @ once.

i ended implementing own find_in_batches_with_lock:

def find_in_batches_with_lock(scope, user, batch_size: 1000)   last_processed_id = 0   records = []   begin     user.transaction       records = scope.where("id > ?", last_processed_id)                      .order(:id).limit(batch_size).lock.all       next if records.empty?       yield records       last_processed_id = records.last.id     end   end while !records.empty? end