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.

One thing stands out: among the durable stores it is the strongest on a read-update mix, and it compresses 1 KB values to about an eighth of their size on disk.

Best at

• Strongest durable engine on a mixed load. 384,000 ops/sec on the 50/50 mixed workload, the closest anything comes to tamnd/kv there, and it holds a controlled tail while doing it.
• Small disk footprint. 0.13x space amplification, second only to goleveldb, and it stays compact under updates. See footprint.
• Balanced everything. 713,000 reads/sec, 158,000 fresh writes/sec, and good ordered scans (367,000 keys/sec), solid on every workload without a weak spot.

Watch out for

• Point reads trail the hash engines. 713,000 reads/sec, good but well behind tamnd/kv and pogreb if reads are the whole job.
• Per-commit durability. 383 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 durable engine that does everything competently and never embarrasses you: a strong mixed load, a small footprint, ordered scans, and a predictable tail. This is the default to pick among the durable stores when you are not sure which scenario you are, especially if the workload involves mixed reads and updates.