GCP – Spanner’s enduring impact: Celebrating the 2025 ACM SIGMOD Systems Award

Earlier this year, the Association for Computing Machinery’s Special Interest Group on Management of Data (ACM SIGMOD) announced that Spanner, Google’s globally distributed database, was awarded the 2025 SIGMOD Systems Award. The SIGMOD Systems Award specifically honors systems whose technical contributions have profoundly impacted the theory or practice of large-scale data management. On behalf of the entire Spanner team, especially the engineers who were there at the beginning of Spanner’s journey, it is with deep humility and immense pride that we receive this recognition from such a distinguished community. We’re thrilled to be participating in the 2025 SIGMOD conference from June 22-27 in Berlin, Germany as a Platinum sponsor.

This honor feels particularly significant following Spanner’s 2022 SIGOPS Hall of Fame Award, which highlighted the crucial role of technologies like TrueTime and our network infrastructure, reaffirming the lasting significance of the original vision laid out in the first Spanner paper.

Spanner’s core innovation: TrueTime and external consistency

For Spanner to be recognized in this way is a powerful affirmation of the vision we set out to achieve years ago and the new ways Spanner enables applications to be built. According to the award citation, Spanner is recognized “for reimagining relational data management to enable serializability with external consistency at global scale.”

Why “reimagining”? Before Spanner, databases offered a stark choice: you could have ACID transactions and SQL, or you could have scale and multi-datacenter reliability. Scale and availability required a distributed system, and that meant eventual consistency and other forms of best-effort synchronization. Spanner showed that this choice was not fundamental — that it was possible to build a database that offered the horizontal scalability of a distributed system with the power and ease of use of transactions and SQL. It enabled companies for whom scale is job #1 to regain developer velocity and agility. Spanner drastically simplifies the logic required in distributed applications. Developers can reason about the state of the database as if it were a single, consistent entity, even when it spans the globe.

The key enabler for Spanner’s ability to deliver external consistency is TrueTime. Beyond just a synchronized global clock, TrueTime is an API that cleverly exposes clock uncertainty as a bounded interval, which allows higher-level algorithms to reason about the ordering of events. Google’s TrueTime implementation uses specialized hardware references like GPS receivers and atomic clocks to provide highly trustworthy and very tight time bounds. Spanner leverages this bounded uncertainty to achieve external consistency. When a transaction commits, Spanner assigns it a commit timestamp derived from TrueTime. Spanner then enforces a “commit wait” — which can be overlapped with making the transaction durable – to ensure that the commit timestamp is definitively in the past before making the transaction’s effects visible. This ensures that the assigned commit timestamps definitively reflect the true global serialization order of transactions, even across data centers. The result is remarkable: external consistency with no performance cost.

 Addressing the consistency-scale dilemma

To truly appreciate the journey, it helps to travel back to the early and mid-2000s at Google. The internet was exploding, and our biggest challenge was scaling our software infrastructure to keep pace. We needed databases that could store and process a copy of the internet using vast fleets of commodity servers. This spurred the development of internal systems that delivered incredible performance and scalability, but they came with trade-offs.

As we gained more familiarity with these systems, and started using them to build big interactive applications like Gmail, we consistently heard from internal developers about the challenge of working with eventual consistency and cross-shard synchronization, as well as the friction of modeling every problem (no matter how complex) as key-value pairs. It quickly became apparent that we needed to build a globally distributed database that offered the familiarity and guarantees of traditional relational databases — including ACID transactions, serializability, and external consistency — without giving up Google’s ever-growing need for bigger databases serving bigger audiences. Moreover, working closely with our customers, it became clear that actually, it was something we could build. The rest is history!

Spanner as a cloud service

As a cornerstone of Google’s infrastructure, Spanner powers some of our most critical, planet-scale services, including Google Ads, Google Search indexing, Gmail, YouTube, Google Photos, metadata for Cloud Storage, and BigQuery, demonstrating its robustness and scalability under extreme load.

The next logical step was to make these capabilities available externally to customers through Google Cloud. The launch and subsequent evolution of  Spanner aimed to democratize this technology, bringing the power of a globally consistent, scalable database to organizations of all sizes, from startups to global enterprises, simplifying their application development and operations.

Spanner’s core value proposition for customers stems directly from its unique architecture:

• Global scale with strong consistency: Spanner delivers on the original promise: ACID transactions with external consistency across a database that can scale horizontally across regions and continents, automatically managing data distribution (sharding) as needed. This directly addresses the capability highlighted by the SIGMOD award.  

• Unmatched availability: Leveraging synchronous, Paxos-based replication across multiple zones or regions, Spanner offers an industry-leading 99.999% availability Service Level Agreement (SLA) for multi-region configurations. This helps provide extreme fault tolerance and minimizes downtime risk for mission-critical applications.  

• Simplified operations: As a fully managed service, Spanner automates complex operational tasks like sharding, replication management, backups, and maintenance. This frees development teams from significant operational burdens, allowing them to focus on building applications rather than managing database infrastructure. This contrasts sharply with the manual effort often required for traditional sharded databases or the complexity of implementing consistency logic at the application layer for NoSQL systems.  

• Developer productivity: Spanner offers familiar SQL query interfaces, supporting both Google SQL and PostgreSQL dialects, which significantly flattens the learning curve for developers. Furthermore, its strong consistency eliminates entire classes of complex problems related to data synchronization and reconciliation that often plague applications built on eventually consistent systems.  

Empowering customers and industries

Of course, today’s data landscape has changed since we published the first Spanner paper in 2012. In the modern AI-first data world, we see customers more focused than ever on getting full value from their data, which is often spread out over many systems with different data models, varying scalability, and uneven reliability. We’re addressing these new challenges head on, introducing Spanner Graph, vector search for AI applications, and integrated full-text search. These allow you to bring together a wide range of data and iterate on it rapidly within a single, consistent, scalable platform. We’ve also helped you run even more cost-effectively as your data grows, with increased compute and storage density, tiered pricing through editions, and cost-optimizing features such as tiered storage. Finally, we’ve made it easier to bring scale-out workloads into Spanner through enhanced interoperability with tools and capabilities, such as  Cassandra-compatible APIs.

While academic recognition such as the SIGMOD award is gratifying, we’ve always felt that the true measure of a system’s impact lies in how it empowers users to solve real-world problems and build innovative applications. Spanner’s unique combination of capabilities have proven transformative across various industries.

In financial services, where consistency, availability, and security are paramount, Spanner provides the foundation for many critical systems. Companies like Goldman Sachs use it to consolidate trade ledgers, while others like Arigato Bank rely on it to handle high volumes of financial transactions with perfect consistency, even during peak loads. Digital-native banks like Minna Bank have built their entire infrastructure on Spanner, leveraging its availability and consistency to meet stringent regulatory requirements and customer expectations.

The gaming industry is constantly pushing the boundaries of scale and real-time interaction. Spanner has helped game developers launch globally successful titles like Dragon Quest Walk by Colopl, handling millions of concurrent players from day one. Its ability to manage player profiles, in-game inventory, and leaderboards consistently across a global player base, while elastically scaling to handle unpredictable traffic spikes, has been crucial for delivering a seamless player experience

In retail and e-commerce, Spanner helps businesses manage the complexities of modern commerce. Walmart uses Spanner to modernize its inventory and payment management, providing a real-time, consistent view across online and physical stores. MercadoLibre, a global online marketplace and e-commerce provider, leverages Spanner to handle the global needs of their customers, including massive demand spikes during major product launches.

Leaders in transportation, such as Uber, rely on Spanner to handle millions of concurrent users and billions of trips per month across over 10,000 cities and billions of database transactions per day.

These examples illustrate that for many modern applications, Spanner’s specific blend of global consistency, massive scalability, high availability and interoperable multi-model isn’t just a technical advantage; it’s a fundamental enabler. Business models built around real-time global inventory, instantaneously consistent financial records, or seamless worldwide multiplayer experiences become significantly simpler, less risky, and more feasible to implement with Spanner.

The future with Spanner

The SIGMOD award recognizes the contributions of over 30 individuals, and countless other current and prior Googlers who have played roles throughout its development and evolution. It’s been a privilege to witness the journey from the initial ambitious concepts to the globally impactful system it is today. The journey from the original OSDI paper published to this 2025 SIGMOD Systems Award highlights over a decade of sustained research, engineering, and investment by Google. This long-term commitment is rare and is a key factor behind Spanner’s enduring success and impact.

Thanks to you, our customers, Spanner remains a living system that continues to evolve, benefiting from ongoing improvements, driven by both internal use and the needs of our cloud customers. Looking ahead, we remain committed to pushing the boundaries of what’s possible with distributed databases. We’re excited about enabling new kinds of applications, including those leveraging AI, and continuing our mission to simplify the complexities of data management for developers building the next generation of world-changing applications.

Experience the Spanner difference 

The 2025 ACM SIGMOD Systems Award is a tremendous honor and a validation of the path we embarked on years ago. If you are at the  2025 SIGMOD conference, join us on Tuesday, June 24 at 4:30 pm to hear from and meet with the Google team. 

If Spanner’s capabilities for consistency, scale, and availability resonate with the challenges you face, we encourage you to learn more:

• Explore Spanner to learn about supported features and use cases, and get started with a 90-day Spanner free trial instance.

• Dive deeper with documentation  

• For the academically inclined, read the original and successor papers on Spanner  

In closing, we believe Spanner unlocks new possibilities for building reliable, scalable, and globally consistent applications, and we are excited to see what you, our customers, will build with it.