Key-value compaction

A method comprising:

• coupling, by a storage I/O (input/output) logic, a storage device to a host device, the storage I/O logic to receive a sort-merge command the host device;
• identifying, by a storage device controller, a level N SSTable (sorted string table) file, a corresponding level N index file, a first level N+1 SSTable file and a corresponding first level N+1 index file, in response to the sort-merge command to be received from the host device;
• and
• performing, by the storage device controller, a sort-merge of the level N SSTable file and the first level N+1 SSTable file to produce a first level N+1 output SSTable file and a first level N+1 output SSTable index file, wherein the first level N+1 output SSTable file replaces the N SSTable file or replaces the first level N+1 SSTable file,
• the level N SSTable file comprising at least one level N key-value (KV) pair, the level N+1 SSTable file comprising at least one level N+1 key-value (KV) pair, the sort-merge command comprising a level N SSTable file index, a value corresponding to a number of SSTable files included in level N+1 and a level N+1 start SSTable file index, the identifying based, at least in part, on the level N SSTable file index and the level N+1 start SSTable file index.

A system comprising a storage device comprising:

• a plurality of nonvolatile media;
• a storage I/O (input/output) logic to couple the storage device to a host device, the storage I/O logic to receive a sort-merge command the host device;
• and
• a storage device controller to identify a level N SSTable (sorted string table) file, a corresponding level N index file, a first level N+1 SSTable file and a corresponding first level N+1 index file, in response to the sort-merge command to be received from the host device;
• and to perform a sort-merge of the level N SSTable file and the first level N+1 SSTable file to produce a first level N+1 output SSTable file and a first level N+1 output SSTable index file, wherein the first level N+1 output SSTable file replaces the N SSTable file or replaces the first level N+1 SSTable file,
• the level N SSTable file comprising at least one level N key-value (KV) pair, the level N+1 SSTable file comprising at least one level N+1 key-value (KV) pair, the sort-merge command comprising a level N SSTable file index, a value corresponding to a number of SSTable files included in level N+1 and a level N+1 start SSTable file index, the identifying based, at least in part, on the level N SSTable file index and the level N+1 start SSTable file index.