Apache Druid

1. The segment metadata contains the contiguous range of values for the dimension on which single_dim secondary partitioning is applied. This is utilized by brokers to prune segments when the query contains a value out of this range for the chosen dimension.
2. ``query/segments/count`` may help but it needs to be enabled

Alternatively, `query/segment/time`  has id, segment as its dimensions. It may help to check the count of segments for a given query id for this metric. (<https://druid.apache.org/docs/latest/operations/metrics.html#historical>)