DynamoDB over RDS

Choosing DynamoDB Over RDS for a LocalStack-Honest Stack

Git to Kubernetes run BookNest on PostgreSQL 1,289 , whose direct AWS 24 translation is Amazon RDS 24 for PostgreSQL in the private subnets. That cannot be shown honestly here, because the pinned image has no RDS, and no ECS either:

Asking LocalStack 4.13.1 for RDS and ECSShell
aws rds describe-db-instances 2>&1 | grep -o 'the rds service is not included[^,]*'
aws ecs list-clusters 2>&1 | grep -o 'the ecs service is not included[^,]*'
Output
the rds service is not included within your LocalStack license
the ecs service is not included within your LocalStack license

So the catalog lives in DynamoDB 24 , a fair substitution: the API's two access patterns, one book or all books, need a single key and no joins. DynamoDB bills per request, costs nothing idle (the smallest RDS instance bills every hour) and needs no connection pool, a real problem when many Lambda 24 instances open PostgreSQL connections. You give up SQL: ad hoc queries, joins and database-enforced constraints. If BookNest grew orders and reports, RDS would return, reached through RDS Proxy from the same subnets.