Samsung patents smarter data cleanup for high-speed SSDs

1. A compaction method for sorted string table (SST) files stored in zones of a zoned namespace solid state drive (ZNS SSD), comprising: determining, based on a compaction operation for a first level of a Log Structure Merge Tree (LSM-Tree), a plurality of first SST files in the first level and a plurality of second SST files in a second level, wherein a key range of at least one of the plurality of first SST files at least partially overlaps with key ranges of the plurality of second SST files in the second level; determining a key overlapping ratio for each of the plurality of first SST files based on an overlap between a key range of a respective first SST file and key ranges of one or more overlapping second SST files, among the plurality of second SST files, that overlap with the key range of the respective first SST file among the plurality of first SST files; determining attribute information for each of a plurality of zones of the ZNS SSD corresponding to the plurality of first SST files, wherein the attribute information comprises at least one of a ratio of a size of invalid files in a respective zone to a capacity of the respective zone, or a usage duration of the respective zone; determining a compaction priority score for each of the plurality of first SST files based on the key overlapping ratio and the attribute information of the respective zone corresponding to the respective first SST file; and performing compaction on a target first SST file having a highest compaction priority score among the plurality of first SST files, wherein performing the compaction comprises: deleting the target first SST file from a corresponding target zone among the plurality of zones, and reclaiming the target zone for storing a new SST file.