Overview
Amazon DynamoDB is the fully managed NoSQL key-value and document database that AWS first released in 2012, evolved from internal experience with the original Dynamo paper. It is among the most scalable databases in commercial use, supporting Amazon.com's flagship shopping events with single-digit millisecond latency at any scale. DynamoDB pricing now extends from on-demand (no capacity planning required, post-November 2024 price reduction of up to 50%) through provisioned capacity with reserved discounts.
DynamoDB is the default operational database for serverless AWS architectures and is tightly integrated with Lambda, API Gateway, AppSync, and Step Functions. The 2024 introduction of Global Tables multi-Region strong consistency, the broader on-demand price cut, and ongoing improvements to PartiQL query support have widened its applicability. The hardest part of running DynamoDB in production has always been data modelling — single-table design and access-pattern-first schemas remain the steepest learning curve.
Key Features
- Single-digit millisecond latency at any throughput with predictable scaling
- Serverless on-demand mode with no capacity planning or provisioning
- Provisioned capacity mode with auto-scaling and reserved capacity discounts
- Global Tables with multi-Region active-active replication (strong consistency option, 2024)
- DynamoDB Streams for change data capture into Lambda, Kinesis, or EventBridge
- Point-in-time recovery (35-day rolling) and on-demand backups to S3
- DAX (DynamoDB Accelerator) for in-memory caching of read-heavy workloads
- Transactional reads and writes across multiple items with ACID guarantees
- PartiQL SQL-compatible query language as an alternative to the native API
- Item-level TTL for automatic expiry of session and ephemeral data
- Encryption at rest with AWS-managed or customer-managed KMS keys
- Native integration with IAM for fine-grained access control
Pricing
| Mode | Model | Cost (us-east-1) |
|---|---|---|
| On-demand writes | Per million write request units | $0.625 per million standard writes |
| On-demand reads | Per million read request units | $0.125 per million eventually-consistent reads |
| Provisioned write capacity | Per WCU/hour | $0.00065/WCU/hour |
| Provisioned read capacity | Per RCU/hour | $0.00013/RCU/hour |
| Reserved capacity (1-year) | WCU/RCU, prepaid | ~53% discount versus provisioned |
| Storage | Per GB/month | $0.25/GB/month |
| Global Tables replicated writes | Per million rWCU | $0.9375 per million |
Pricing verified May 2026 from AWS public pricing for us-east-1. On-demand pricing reflects the November 2024 reduction of up to 50%. Cross-region data transfer, PITR, and backup storage are additional. Reserved capacity requires 1-year or 3-year commitment.
Strengths
- Operationally unmatched — true zero-administration database at internet scale
- Predictable single-digit millisecond p99 latency under variable load
- Tightest integration of any database with the AWS serverless stack
- Global Tables with strong consistency is rare in commercial multi-region databases
- On-demand mode eliminates capacity planning for variable workloads
- Reserved capacity and the 2024 on-demand price cut materially improve cost predictability
Limitations
- Steep data-modelling learning curve — single-table design is non-intuitive
- No native joins, aggregations, or ad-hoc analytic queries (export to S3 for analysis)
- Item size limited to 400 KB; secondary index limits constrain access pattern flexibility
- Migration off DynamoDB is non-trivial — locks customers into AWS
- Cost can rise rapidly with unindexed scans or poorly distributed partition keys