This is the last day of Week 6. DynamoDB is the service that generates more exam questions than any other on DVA-C02, and plain memorization won't hold up against reworded variations. Today we connect everything the week covered — the mathematics of partition key design, the read consistency models, the internal differences between LSI and GSI, the DAX cache layer, Streams plus Lambda integration, the two-phase commit behind transactions, and TTL's asynchronous deletion — into a single map, then close with comprehensive questions in real exam format