DVA-C02 Development with AWS Services Practice Question
A developer is implementing an e-commerce application where a purchase operation must deduct inventory and create an order atomically. The inventory and orders are stored in separate DynamoDB tables. Which DynamoDB feature should the developer use to execute these operations as a single, all-or-nothing transaction?
⚠ Common exam trap
A common mix-up: candidates confuse DynamoDB Streams with transactional capabilities, assuming that capturing changes in order guarantees atomicity, but Streams are asynchronous and cannot enforce all-or-nothing semantics across multiple tables.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
DynamoDB Transactions
DynamoDB Transactions provide ACID (Atomicity, Consistency, Isolation, Durability) guarantees across one or more tables within a single AWS account and region. This allows the developer to combine the deduct-inventory and create-order operations into a single all-or-nothing transaction, ensuring that both succeed or both fail without partial updates.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
DynamoDB Streams
Why it's wrong here
DynamoDB Streams capture a time-ordered sequence of item-level modifications (inserts, updates, deletes) in a DynamoDB table, publishing them as events to which other AWS services can subscribe. While useful for auditing, real-time analytics, or triggering downstream processes, Streams do not provide atomicity for operations involving multiple items or across different tables. They merely record changes *after* they occur, offering no mechanism to ensure that a group of writes either all succeed or all fail together.
- ✓
DynamoDB Transactions
Why this is correct
DynamoDB Transactions, specifically using `TransactWriteItems` or `TransactGetItems`, provide full ACID (Atomicity, Consistency, Isolation, Durability) guarantees for operations involving multiple items within a single table or across multiple tables. For an e-commerce purchase, this ensures that critical related operations, such as deducting inventory from one item and simultaneously creating a new order record, are treated as a single, indivisible unit. If any part of the transaction fails, all changes are rolled back, preventing data inconsistencies.
- ✗
DynamoDB Accelerator (DAX)
Why it's wrong here
DynamoDB Accelerator (DAX) is an in-memory cache designed to provide microsecond response times for eventually consistent read operations, significantly improving performance for read-heavy workloads. It sits in front of DynamoDB, transparently caching data to reduce the load on the underlying database. However, DAX is purely a read-caching layer and has no functionality related to ensuring the atomicity of write operations or managing transactional integrity across multiple data modifications.
- ✗
DynamoDB Global Tables
Why it's wrong here
DynamoDB Global Tables provide a fully managed, multi-region, active-active replication solution, enabling applications to deliver low-latency data access to users worldwide and enhance disaster recovery capabilities. They automatically replicate data changes across specified AWS regions. While Global Tables ensure data availability and eventual consistency across regions, they do not inherently provide transactional atomicity for multi-item operations within a single region or across regions. Their purpose is replication, not transactional integrity for complex writes.
Go deeper
Related to this question
About these practice questions
Courseiva writes every DVA-C02 question from scratch — 724 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DVA-C02 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the DVA-C02 exam.