使用‘时间维度聚合’查询时，返回的ts的含义是什么？

[Luokun2016]

使用时间维度聚合查询时，返回的时间点含义是什么？
如下图，数据库中的数据从 2020-12-18 07:57:01.000才有数据，
时间维度聚合后时间就从2020-12-18 07:55:00.000开始的

select * from fcloudqa.tb4556512529240555520 where ts > '2020-12-18 00:00:00' and ts < '2020-12-18 23:59:59'

{
    "status": "succ",
    "head": [
        "ts",
        "val"
    ],
    "data": [
        [
            "2020-12-18 07:57:01.000",
            0.000000000
        ],
        [
            "2020-12-18 07:57:02.000",
            0.000000000
        ],
        [
            "2020-12-18 07:57:03.000",
            0.000000000
        ],
        [
            "2020-12-18 07:57:04.000",
            0.000000000
        ],
        [

select avg(val) from fcloudqa.tb4556512529240555520 where ts > '2020-12-18 00:00:00' and ts < '2020-12-18 23:59:59' interval(5m)

{
    "status": "succ",
    "head": [
        "ts",
        "avg(val)"
    ],
    "data": [
        [
            "2020-12-18 07:55:00.000",
            0.000000000
        ],
        [
            "2020-12-18 08:00:00.000",
            0.000000000
        ],
        [
            "2020-12-18 08:05:00.000",
            0.000000000
        ],
        [
            "2020-12-18 08:10:00.000",
            0.000000000
        ],

[sangshuduo]

因为用了 interval ，结果返回的 ts 是时间窗口的起始时间