indexer.py 文件源码

def server_cursor_query(queryset, cursor_id=0, chunk_size=DEFAULT_CHUNK_SIZE):
    connection.cursor()

    compiler = queryset.query.get_compiler(using=queryset.db)
    sql, params = compiler.as_sql()

    model = compiler.klass_info['model']
    select_fields = compiler.klass_info['select_fields']
    fields = [field[0].target.attname
              for field in compiler.select[select_fields[0]:select_fields[-1] + 1]]

    cursor_name = 'cursor-large-%d' % cursor_id
    cursor = connection.connection.cursor(name=cursor_name)
    with transaction.atomic(savepoint=False):
        cursor.execute(sql, params)

        while True:
            rows = cursor.fetchmany(chunk_size)
            if not rows:
                break
            for row in rows:
                DBObj = namedtuple('DBObj', fields)
                obj = DBObj(*row[select_fields[0]:select_fields[-1] + 1])
                yield obj