pebble

Shape: LSM, pure Go, ordered Repository: github.com/cockroachdb/pebble

pebble is the storage engine underneath CockroachDB, a mature LSM built for exactly the kind of sustained, concurrent, durable workload a database server runs. It is rarely the single fastest engine on any one row, and it is the most consistent across all of them, which is what makes it a safe default.

Two things stand out: it is the only engine here whose write rate goes up on a server versus the laptop, and it compresses 1 KB values to roughly a quarter of their size on disk.

Best at

• Sustained writes on a server. 120,000, 92,000, and 72,000 writes/sec on the 4, 6, and 8-core Linux hosts, fastest on every one, because its compaction scales across cores. See ingest.
• Small disk footprint. 0.26x space amplification, and it stays compact under updates. See footprint.
• Balanced everything. Solid reads, good ordered scans (450,000 keys/sec), controlled tail latency on mixed loads.

Watch out for

• Point reads trail the hash engines. 856,000 reads/sec, good but well behind tamnd/kv and pogreb if reads are the whole job.
• Per-commit durability. 980 durable writes/sec; it does not group-commit like badger, so for high-rate durable writes badger is faster.

Reach for it when

You want one engine that does everything competently on a server and never embarrasses you: writes that scale, a small footprint, ordered scans, and a predictable tail. This is the default to pick when you are not sure which scenario you are, especially if the workload involves mixed reads and updates.