Amazon DynamoDB is a serverless, fully managed key-value and document database provided by Amazon Web Services. It offers on-demand or provisioned capacity, global tables, ACID transactions and secondary indexes. Its documentation notes that it has no JOIN operator, so data models need to be designed around the access patterns the application will use.
DynamoDB is a proprietary managed service. It runs only on AWS, and there is no self-managed or downloadable edition, so buyers should consider the dependence on a single cloud provider. Because it is a service, it has no major, minor or patch versions in the usual sense and users do not upgrade it themselves. The service was launched in 2012.
Pricing is published by AWS. There is an always-free tier of 25 GB of storage and 25 write capacity units and 25 read capacity units each month. Beyond that, costs follow either on-demand or provisioned capacity, although the individual rates should be taken from the AWS pricing page.
The key-value model with document support means items are stored and retrieved by key, which suits applications with predictable lookups. Teams that need ad hoc relational queries or joins across tables should consider whether a different engine would fit better, or plan to export data to one.