Editor's Note: This post was originally authored when CockroachDB was pre-1.0. CockroachDB's architecture has undergone many changes since then. One of the most significant, as it relates to this post which focuses on our previous "lockless" design, is that we now use more locking and lock-like structures to provide SERIALIZABLE isolation. For more current details about CockroachDB's transaction model, read our transaction layer architecture documentation.

Editor's Note - April 23, 2021: This article was written in 2015 when CockroachDB was pre-beta. The product has evolved significantly since then. We will be updating this post to reflect the current status of CockroachDB. In the meantime, the transaction section of the Architecture Document provides a more current description of CockroachDB's transaction model.