Enhancement

Applying a snapshot requires writing a delete range and a DTFile to the Delta layer of 1 or more segments. Because the snapshot is relatively large, it will

• Very likely trigger a delta merge, which causes write amplification.
• A big snapshot will directly cause write stall.

Note that, most of the time, the snapshot is not overlapped with the data in the relative segments. I think we can find a way to avoid writing snapshots to the Delta layer, as LSM-Tree does.