with gzip.open(filepath, 'rt', newline='') as gzip_file:
                dr = csv.DictReader(gzip_file)  # comma is default delimiter
                chunksize = oci.settings.CHUNKSIZE
                total_chunks = math.ceil(rows_count / chunksize)

                # for chunk in tqdm(oci.utils.chunker.gen_chunks(dr, chunksize=oci.settings.CHUNKSIZE),
                #                   total=total_chunks):
                operations = []
                for row in tqdm(dr, total=rows_count):
                    cell = {
                        'mcc': int(row['mcc']),
                        'mnc': int(row['net']),
                        'lac': int(row['area']),
                        'cell': int(row['cell'])
                    }
                    location = {
                        'lat': float(row['lat']),
                        'lon': float(row['lon'])
                    }
                    operations.append(UpdateOne(cell, {'$set': {source.source_name: location}}, upsert=True))

                    if len(operations) == chunksize:
                        locations.bulk_write(operations, ordered=False)
                        operations = []
                if len(operations) > 0:
                    locations.bulk_write(operations, ordered=False)