Choosing a suitable database for your startup: A overview of AlloyDB and Spanner

Choosing a suitable database for your startup: A overview of AlloyDB and Spanner

In today’s fast-paced business environment, startups need to leverage the power of the cloud to achieve scale, performance, and consistency for their apps. Google Cloud provides three popular cloud databases that enable reliable PostgreSQL: Spanner, AlloyDB and Cloud SQL. In this article, we will explore the features and benefits of these databases, focusing on AlloyDB and Spanner and how startups can use them — together or separately — to simplify infrastructure, reduce operational costs, and maximize performance.

Spanner: a scalable and globally distributed database

Spanner is a fully managed database for both relational and non-relational workloads that is designed to scale horizontally across multiple regions and continents. Combining strong consistency, high availability, and low latency, it stands as the ideal solution for mission-critical applications demanding high throughput and rapid response times.

Spanner provides a PostgreSQL interface, ensuring your schemas and queries are portable to other environments within or outside of Google Cloud. This also allows developers to leverage many of the tools and techniques they already know, flattening the learning curve when transitioning to Spanner.

One of the key features of Spanner is its ability to replicate data across multiple regions while maintaining strong, ACID (atomicity, consistency, isolation, durability) transactions and a familiar SQL interface. On top of that, Spanner offers schema changes without downtime, fully automatic data replication, and data redundancy. As a result, developers can build applications that operate seamlessly across multiple regions without worrying about data consistency issues, regional failures, or planned maintenance.


When is Spanner the right fit?

Spanner also offers automatic horizontal scaling, from an inexpensive slice of one compute node to thousands of nodes (see in graph below), making it easy for a startup to increase or decrease their query and data capacity based on their workload demands. Spanner allows you to resize elastically without downtime or other disruption, so you can better align your usage with the workload. As a result, startups save money by paying only for the resources needed. In contrast to legacy scale-up databases, changing capacity typically involves 1) standing up new infrastructure, 2) migrating the schema and all of the data, and 3) a big-bang cutover in coordination with downstream applications.

Spanner allows you to adjust capacity — read and write — on the fly with no downtime. The autoscaler tool of the database adjusts the capacity for you based on signals, such as CPU usage. The tool scales linearly from tiny workloads (1 node and 400GB of data) to thousands of nodes and PB of data. For example, Niantic runs 5,000 node instances handling the traffic for Pokémon GO. This elasticity saves you money, reduces risks, and provides scale insurance. Even if you aren’t there today, rest assured you can grow to Niantic or Gmail-sized workloads without disruptive re-architecture with Spanner.


Start small and scale with Spanner

AlloyDB: A cloud-native and managed PostgreSQL database

Google Cloud AlloyDB for PostgreSQL is a fully managed, PostgreSQL-compatible database service that’s designed for your most demanding workloads, including 1) transactional, 2) analytical, and 3) hybrid transactional and analytical processing (HTAP).

In Google’s performance tests, AlloyDB delivers up to 100X faster analytical queries than standard PostgreSQL and is more than 2X faster than Amazon’s comparable PostgreSQL-compatible service for transactional workloads.

AlloyDB also offers a number of features designed to simplify application development. For example, it supports standard PostgreSQL syntax and extensions, making it easy to write queries and manipulate data. Another important consideration: AlloyDB may be the better choice if you’re planning to build GenAI apps, thanks to AlloyDB AI, a built-in set of capabilities for working with vectors, models, and data.

AlloyDB uses columnar storage for its columnar engine, which is designed to accelerate analytical queries. The columnar engine stores frequently queried data in an in-memory, columnar format, which can significantly improve the performance of these queries.


Intelligent, workload-aware dynamic data organization leverages both row-based and column-based formats. Multiple layers of cache ensure excellent price-performance.

Choosing the right database for your startup

When it comes to choosing the right database for your startup, there are several factors to consider. First and foremost, you need to consider your application’s requirements in terms of performance, availability, global consistency, and scalability. Are you building a consumer app for millions of concurrent users? Maybe a corporate app that will be used for real-time analytics? Each database has its own strengths.





Cloud-native, managed PostgreSQL database

Globally distributed scalable database

Supported engines


PostgreSQL, GoogleSQL 


Data encryption at rest and in transit

Data encryption at rest and in transit

Data residency

Single region by default, multi-region available

Multi-region by default

Best for

Hybrid transactional & analytical workloads, AI applications

Mission-critical apps with high data consistency & global reach (multi-writer across regions)

Spanner is the ideal choice for mission-critical applications that demand high scalability, unwavering consistency, and 99.999% SLA availability. Teams building applications that are evaluating sharding or active-active configurations, to work around scaling limitations can benefit from Spanner’s built-in, hands-free operations. Spanner enables development teams with its familiar SQL interface (including PostgreSQL dialect support) for seamless large-scale data processing. This ensures portability, flexibility, and simplifies use cases requiring high write scaling, global consistency, and adaptability to variable traffic.

AlloyDB is a good choice for applications that need a high-performance, reliable, and scalable database with built-in support for advanced analytics and full PostgreSQL compatibility. AlloyDB supports real-time analytics applications because of its automatic data placement across tiers (e.g., buffer cache, ultra-fast cache, and block storage), and its ability to process up to 64 TiB of data per cluster in real time. AlloyDB is also reliable and offers a 99.99% SLA, including maintenance.

Another option to consider is Cloud SQL, an enterprise-ready, fully managed relational database service that offers PostgreSQL, MySQL, and SQL Server engines. It is user-friendly as it provides a straightforward user interface with the familiar SQL interface with PostgreSQL, MySQL and SQL Server for easy interaction and only takes minutes to get your database up and running.

Additionally, another important factor to keep in mind is your team’s expertise and familiarity with different database technologies. If your team is already familiar with relational databases and the Google Cloud ecosystem, then Spanner may be the easier choice. If your team is more comfortable with PostgreSQL, then AlloyDB may be the better fit.


In conclusion, Spanner and AlloyDB are two powerful databases that offer different benefits and features for startups and can be used together or separately, depending on your needs.  

Together, AlloyDB and Spanner are a dynamic duo with which you can achieve performance and scalability based on Google’s innovations, delivering both responsive user interactions and robust, scalable back-end functionalities. With PostgreSQL and Google Cloud as the unifying threads, both services can co-exist seamlessly, forming a powerful combination for any application demanding high performance and unwavering reliability. For example, uses AlloyDB and Spanner together in the same app that is at core of their business:

  • AlloyDB for powering the interactive experience: At the user-facing front-end, AlloyDB shines as the engine behind quick, responsive interactions. Its unparalleled speed and performance ensure a smooth and intuitive user experience, critical for engaging with the AI model.

  • Spanner as the backbone of history and workflow: Behind the scenes, Spanner maintains the complete history and workflow data integral to the AI integration. Its unshakeable scale and availability guarantee seamless data management, regardless of load or complexity.

Both Spanner and AlloyDB operate within the familiar PostgreSQL ecosystem, offering a consistent and unified development experience. This empowers developers to leverage their existing skills and knowledge, accelerating integration and workflow. Additionally, the Google Cloud Platform provides a robust and secure environment for both services, ensuring seamless data management and operational efficiency.