CockroachDB

It speaks PostgreSQL wire protocol, so your existing Postgres tools and drivers work with it. Go. The distributed architecture means your data lives on multiple machines simultaneously, and the database handles consistency (serializable isolation by default, which is stronger than most). Automatic sharding, automatic rebalancing, geo-partitioning for compliance.

CockroachDB has a complicated licensing history. The core is now under a Business Source License (BSL). You can use it freely for most purposes, but you can't offer it as a managed service. CockroachDB Serverless has a free tier: 10 GiB storage, 50M request units/month.

Self-hosting is free under BSL. Minimum production cluster: 3 nodes. On modest cloud VMs, that's $50-150/mo. The ops burden is moderate. CockroachDB handles a lot of distributed complexity for you, but you still need to monitor rebalancing, node health, and storage. Solo developers: the serverless free tier is solid for prototyping. Small teams: self-host 3 nodes or use serverless. Medium to large: this is where CockroachDB earns its keep: multi-region, zero-downtime migrations, strong consistency.

The catch: single-node performance is slower than plain Postgres. The distributed overhead means simple queries pay a latency tax. If your app fits on one machine and you don't need multi-region, you're paying complexity costs for resilience you don't need yet.