The database industry has undergone a quiet revolution over the past decade.

Traditional databases required administrators to provision fixed capacity, including both compute and storage resources. Even in the cloud, with database-as-a-service options, organizations were essentially paying for server capacity that sits idle most of the time but can handle peak loads. Serverless databases flip this model. They automatically scale compute resources up and down based on actual demand and charge only for what gets used.

Amazon Web Services (AWS) pioneered this approach over a decade ago with its DynamoDB and has expanded it to relational databases with Aurora Serverless. Now, AWS is taking the next step in the serverless transformation of its database portfolio with the general availability of Amazon DocumentDB Serverless. This brings automatic scaling to MongoDB-compatible document databases.

The timing reflects a fundamental shift in how applications consume database resources, particularly with the rise of AI agents. Serverless is ideal for unpredictable demand scenarios, which is precisely how agentic AI workloads behave.

“We are seeing that more of the agentic AI workloads fall into the elastic and less-predictable end,” Ganapathy (G2) Krishnamoorthy,  VP of AWS Databases, told VentureBeat.”So actually agents and serverless just really go hand in hand.”

Serverless vs Database-as-a-Service compared

The economic case for serverless databases becomes compelling when examining how traditional provisioning works. Organizations typically provision database capacity for peak loads, then pay for that capacity 24/7 regardless of actual usage. This means paying for idle resources during off-peak hours, weekends and seasonal lulls.

“If your workload demand is actually just more dynamic or less predictable, then serverless actually fits best because it gives you capacity and scale headroom, without actually having to pay for the peak at all times,” Krishnamoorthy explained.

AWS claims Amazon DocumentDB Serverless can reduce costs by up to 90% compared to traditional provisioned databases for variable workloads. The savings come from automatic scaling that matches capacity to actual demand in real-time.

A potential risk with a serverless database, however, can be cost certainty. With a Database-as-a-Service option, organizations typically pay a fixed cost for a ‘T-shirt-sized’ small, medium or large database configuration. With serverless, there isn’t the same specific cost structure in place.

Krishnamoorthy noted that AWS has implemented the concept of cost guardrails for serverless databases through minimum and maximum thresholds, preventing runaway expenses.

What DocumentDB is and why it matters

DocumentDB serves as AWS’s managed document database service with MongoDB API compatibility.

Unlike relational databases that store data in rigid tables, document databases store information as JSON (JavaScript Object Notation) documents. This makes them ideal for applications that need flexible data structures.

The service handles common use cases, including gaming applications that store player profile details, ecommerce platforms managing product catalogs with varying attributes and content management systems. 

The MongoDB compatibility creates a migration path for organizations currently running MongoDB. From a competitive perspective, MongoDB can run on any cloud, while Amazon DocumentDB is only on AWS.

The risk of lock-in can potentially be a concern, but it is an issue that AWS is trying to address in different ways. One way is by enabling a federated query capability. Krishnamoorthy noted that it’s possible to use an AWS database to query data that might be in another cloud provider.

“It is a reality that most customers have their infrastructure spread across multiple clouds,” Krishnamoorthy said. “We look at, essentially, just what problems are actually customers trying to solve.”

How DocumentDB serverless fits into the agentic AI landscape

AI agents present a unique challenge for database administrators because their resource consumption patterns are difficult to predict. Unlike traditional web applications, which typically have relatively steady traffic patterns, agents can trigger cascading database interactions that administrators cannot predict.

Traditional document databases require administrators to provision for peak capacity. This leaves resources idle during quiet periods. With AI agents, those peaks can be sudden and massive. The serverless approach eliminates this guesswork by automatically scaling compute resources based on actual demand rather than predicted capacity needs.

Beyond just being a document database, Krishnamoorthy noted that Amazon DocumentDB Serverless will also support and work with MCP (Model Context Protocol), which is widely used to enable AI tools to work with data.

As it turns out, MCP at its core foundation is a set of JSON APIs. As a JSON-based database this can make Amazon DocumentDB a more familiar experience for developers to work with, according to Krishnamoorthy.

Why it matters for enterprises: Operational simplification beyond cost savings

While cost reduction gets the headlines, the operational benefits of serverless may prove more significant for enterprise adoption. Serverless eliminates the need for capacity planning, one of the most time-consuming and error-prone aspects of database administration.

“Serverless actually just scales just right to actually just fit your needs,”Krishnamoorthy said.”The second thing is that it actually reduces the amount of operational burden you have, because you’re not actually just capacity planning.”

This operational simplification becomes more valuable as organizations scale their AI initiatives. Instead of database administrators constantly adjusting capacity based on agent usage patterns, the system handles scaling automatically. This frees teams to focus on application development.

For enterprises looking to lead the way in AI, this news means document databases in AWS can now scale seamlessly with unpredictable agent workloads while reducing both operational complexity and infrastructure costs. The serverless model provides a foundation for AI experiments that can scale automatically without upfront capacity planning.

For enterprises looking to adopt AI later in the cycle, this means serverless architectures are becoming the baseline expectation for AI-ready database infrastructure. Waiting to adopt serverless document databases may put organizations at a competitive disadvantage when they eventually deploy AI agents and other dynamic workloads that benefit from automatic scaling.