Exam AZ-204 topic 3 question 37 discussion

Agreed! To update multiple documents for a username in a single ACID operation in Azure Cosmos DB, you need to ensure that the documents are stored in the same logical partition. To do this, you should perform the following actions: Create an unsharded collection to store documents. This will ensure that all documents are stored in the same logical partition. Configure Azure Cosmos DB to use the MongoDB API. The MongoDB API supports multi-document ACID transactions, which allow you to update multiple documents in a single atomic operation.

Got this in exam today (5 April 2023)

Forget previous comment, not correct

I think it is AD because you need to shard across partitions on username to be able to process all documents with that user name in one transactional batch. You have to create a shard key for this in the cosmos db container based on the username.

Correct answer is AD

To update multiple documents for a username in a single ACID operation in Azure Cosmos DB, you should perform the following actions: C. Create an unsharded collection to store documents, since sharded collections do not support multi-document transactions. D. Configure Azure Cosmos DB to use the MongoDB API, since it is the only API that supports multi-document transactions. Therefore, the correct actions are C and D.

Agreed!

It was there in 13 Feb 2023 exam

CD are correct update multiple documents for a username in a single ACID operation.

multi-document transaction is only supported within unsharded collection. https://learn.microsoft.com/en-us/azure/cosmos-db/mongodb/use-multi-document-transactions#requirements