'Set up and execute delete queries for all the objects in pk_list.
More than one physical query may be executed if there are a
lot of values in pk_list.'

def delete_batch(self, pk_list, using, field=None):

    if (not field):
        field = self.get_meta().pk
    for offset in range(0, len(pk_list), GET_ITERATOR_CHUNK_SIZE):
        where = self.where_class()
        where.add((Constraint(None, field.column, field), 'in', pk_list[offset:(offset + GET_ITERATOR_CHUNK_SIZE)]), AND)
        self.do_query(self.get_meta().db_table, where, using=using)
