Questions about rocksdb compaction

[wanglinke521]

Note: Please use Issues only for bug reports. For questions, discussions, feature requests, etc. post to dev group: https://groups.google.com/forum/#!forum/rocksdb or https://www.facebook.com/groups/rocksdb.dev

When I delete the sst file in L0-L3 layers of rocksdb, will the sst file in L4 layer return to L0-L3 or go to L5 after compaction? Can you help answer my question? Thank you very much.

[ajkr]

Automatic compaction merges files gradually to deeper levels, i.e., L4+. There are some manual compaction settings that can write files to shallower empty levels (L1-L3), like CompactRange() with CompactRangeOptions::change_level set to true.