Exam AWS Certified Developer Associate topic 1 question 52 discussion

Ans: B DynamoDB optionally supports conditional writes for these operations. A conditional write succeeds only if the item attributes meet one or more expected conditions. Otherwise, it returns an error. Conditional writes are helpful in many situations. For example, you might want a PutItem operation to succeed only if there is not already an item with the same primary key. Or you could prevent an UpdateItem operation from modifying an item if one of its attributes has a certain value. Conditional writes are helpful in cases where multiple users attempt to modify the same item.

B is the correct answere There are two ways to ensure that lost updates phenomenon does not happen in DynamoDB tables: using Conditional Writes in DyanmoDB using Optimistic Locking using @Version support In this scenario optimistic locking is not mentioned

B) Correct - Conditional writes allow you to prevent overwriting an item unless certain conditions are met. This ensures that concurrent updates are managed properly and that updates are only applied if the item has not been modified by another process in the meantime. This is ideal in scenarios where multiple users or processes are updating the same data concurrently, such as with the pricing information in this e-commerce application

Yep, it may happen that if we update the price for a specific product at the same time, we have an inconsistent data. DynamoDB allows us to specify a condition to be satisfied before update the information. We obtain this with conditional writes and we can use the Primary key or the version as condition in order to be sure to update the specific item on the table

ANS: B

B. Conditional Writes in DynamoDB called as Optimistic locking technique in DB where you check if the record was updated by someone else before you commit the transaction.

Answer: B

B. Conditional writes

Resp: B

B. Conditional writes

B. Conditional writes

Ans: B https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithItems.html#WorkingWithItems.ConditionalUpdate

Correct Answer is "B"