Compaction
Push a SSTable down and merge it with all overlapping SSTable at the next lower level.
Leave only the record with the greatest seq when merging.
When reaching the bottom level, i.e, level-0, a tombstone record can be removed for good.
Push a SSTable down and merge it with all overlapping SSTable at the next lower level.
Leave only the record with the greatest seq when merging.
When reaching the bottom level, i.e, level-0, a tombstone record can be removed for good.