Cloud Spanner
Enterprise-grade, globally distributed relational database with unlimited scale and 99.999% availability.
Enterprise-grade, globally distributed relational database with unlimited scale and 99.999% availability.
What is Cloud Spanner?
Google Cloud Spanner is the world's first fully managed relational database service that combines the benefits of relational database structure (schemas, ACID transactions, SQL) with non-relational horizontal scale. Spanner uses atomic clocks and GPS receivers in Google data centers (TrueTime API) to achieve external consistency globally without locking overhead, offering an unprecedented 99.999% availability SLA.
Decision Guide: When to Choose This Service
Use Cloud Spanner for massive global relational workloads (financial ledgers, global gaming inventory, large-scale supply chain) requiring strict ACID transactions, relational schemas, high-throughput writes, and five-nines (99.999%) availability with zero downtime maintenance.
Do NOT use Cloud Spanner for small-scale applications that fit easily within Cloud SQL (<64 TB) where the minimum hourly cost of a Spanner instance is not economically justified.
Core Architectural Pillars
Google's synchronized hardware atomic clocks providing bounded global time uncertainty for lock-free consistent distributed transactions.
Distributed multi-region read-write transactions with strong serializable consistency.
Granular scaling unit (100 PUs = 0.1 node, allowing low-cost entry points).
Physically co-locate parent and child table rows together on the same storage split for ultra-fast relational joins without cross-network hops.
Supports GoogleSQL and PostgreSQL dialects natively.