AWS DevOps Engineer Professional Practice Test

What is the appropriate API call to perform a series of DynamoDB writes in a transactionally consistent fashion?

1. GetItem

2. PutItem

3. TransactWriteItems

4. BatchWriteItem

The correct answer is: TransactWriteItems

Using the TransactWriteItems API call is the appropriate choice for performing a series of DynamoDB writes in a transactionally consistent manner. This API allows you to execute multiple PutItem, UpdateItem, or DeleteItem operations as a single, atomic transaction. This means all the operations specified in the TransactWriteItems request will either succeed or fail together, ensuring that the data remains consistent. Transactional integrity is critical in scenarios where it's essential that a group of write operations either all succeed or none at all, preserving data integrity across multiple items and tables. For example, if you're updating several records that depend on each other, using TransactWriteItems guarantees that no partial updates will occur. The other options, while related to DynamoDB operations, do not provide the same transactional guarantees. GetItem is used for retrieving an item from a table, which does not involve writing or transactions. PutItem allows you to add or replace an item in a table but operates independently without transactional support. BatchWriteItem can perform multiple write operations but does not ensure that all operations complete successfully as a single atomic transaction, which may lead to some writes being processed while others fail. Thus, TransactWriteItems is the only choice that meets the requirement for transactionally consistent writes