Should DynamoDB be the default recommendation for AWS?

Question

Now that DynamoDB supports transactions for up to ten items, and also offers API for consistent reads, shouldn't it be the default selection for database on AWS? Not only is it providing all features of RDBMS, but much more because it is fully managed by AWS, provides fantastic features like DAX (inbuilt cache) and streams, and tuned for single digit latency.

Answer 1

DynamoDB does not provide all of the features of a RDBMS. Notable things lacking are are multi-table joins, efficient querying by non-indexed attributes, aggregation queries, and supporting adhoc access patterns.

Regarding latency, single digit millisecond latency is the fastest you are likely to achieve.

As in most software development and infrastructure design choices, the correct implementation depends on the requirements. There is no one size fits all approach.