At its foundation, CockroachDB depends on a key-value storage engine called Pebble. In CockroachDB v25.4, the storage team introduced value separation within Pebble: an optimization that improves compaction efficiency for many workloads. Value separation increases the throughput of the core of CockroachDB, the storage engine, by up to ~50%, depending on the workload, through algorithmic improvements. It reduces redundant I/O, reducing cost-to-serve at scale. We’ll look at how Pebble represents data today, what’s changed, and how that translates to database efficiency.

Jackson Owens

January 13, 2026

This is part 3 of a 3-part blog series about how we’ve improved the way CockroachDB stores and modifies data in bulk (here is part 1 and here is part II). We went way down into the deepest layers of our storage system, then up to our SQL schema changes and their transaction timestamps - all without anybody noticing (or at least we hope!)

Jackson Owens

January 19, 2023