【 TiDB 使用环境】测试
【 TiDB 版本】6.5.0
【复现路径】sysbench 导入测试数据
【遇到的问题：问题现象及影响】WRITTEN_BYTES=0，APPROXIMATE_SIZE=95M，是什么原因？
【资源配置】
【附件：截图/日志/监控】
查询数据表 TIKV_REGION_STATUS 中指定 region_id 的大小，结果如下所示：
MySQL [information_schema]> SELECT * FROM tikv_region_status where region_id=188 \G
*************************** 1. row ***************************
REGION_ID: 188
START_KEY: 7480000000000000FF525F698000000000FF0000010380000000FF0041789603800000FF000002BBD8000000FD
END_KEY: 7480000000000000FF525F728000000000FF0647410000000000FA
TABLE_ID: 82
DB_NAME: sbtest
TABLE_NAME: sbtest1
IS_INDEX: 1
INDEX_ID: 1
INDEX_NAME: k_1
EPOCH_CONF_VER: 5
EPOCH_VERSION: 89
WRITTEN_BYTES: 0
READ_BYTES: 0
APPROXIMATE_SIZE: 95
APPROXIMATE_KEYS: 410870
REPLICATIONSTATUS_STATE: NULL
REPLICATIONSTATUS_STATEID: NULL
*************************** 2. row ***************************
REGION_ID: 188
START_KEY: 7480000000000000FF525F698000000000FF0000010380000000FF0041789603800000FF000002BBD8000000FD
END_KEY: 7480000000000000FF525F728000000000FF0647410000000000FA
TABLE_ID: 82
DB_NAME: sbtest
TABLE_NAME: sbtest1
IS_INDEX: 0
INDEX_ID: NULL
INDEX_NAME: NULL
EPOCH_CONF_VER: 5
EPOCH_VERSION: 89
WRITTEN_BYTES: 0
READ_BYTES: 0
APPROXIMATE_SIZE: 95
APPROXIMATE_KEYS: 410870
REPLICATIONSTATUS_STATE: NULL
REPLICATIONSTATUS_STATEID: NULL
2 rows in set (0.01 sec)
问题：
WRITTEN_BYTES 的定义是：已经往 Region 写入的数据量 (bytes)
可是，刚导入后为什么 WRITTEN_BYTES=0？