Cloud Spanner

Cloud Spanner is Google Cloud's globally distributed, strongly consistent, relational database service. It combines the structure and query capabilities of a traditional relational database with the horizontal scalability of a NoSQL system. Spanner is designed for mission-critical applications that require global distribution, strong consistency, and five-nines availability.

---

What Is Cloud Spanner?

Cloud Spanner is a fully managed, horizontally scalable relational database that provides:

• Global distribution — data is automatically replicated across regions and continents.
• Strong consistency — ACID transactions with external consistency (the strongest form of consistency, stronger than serialisable isolation).
• SQL interface — standard SQL with joins, indexes, and a familiar query experience.
• Horizontal scaling — add nodes to increase throughput and storage without downtime.
• 99.999% SLA — five-nines availability for multi-region configurations.

---

How Cloud Spanner Works

TrueTime

Spanner's secret weapon is TrueTime, a globally synchronised clock system based on GPS receivers and atomic clocks in every Google data centre. TrueTime gives Spanner a precise, bounded notion of time across the globe, enabling it to order transactions consistently without the performance penalty of traditional distributed locking.

Splits