Implement Data Access by Using Azure Cosmos DB for NoSQL SDKs DP-420 Practice Questions (Page 9)

Questions 41–45

1. 41foundation · easy

   What is the purpose of a continuation token in Azure Cosmos DB query operations?

   • AIt is used to authenticate the query request.
   • BIt is used to sort the results of the query.
   • CIt is used to specify the consistency level for the query.
   • DIt allows the query to resume from where it left off, enabling pagination through large result sets.
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2. 42application · medium

   A collaboration app stores shared documents in Azure Cosmos DB for NoSQL. Multiple users can edit the same document. The app reads a document, displays it, and later saves changes. If another user saved changes in the meantime, the app should not overwrite them and should notify the user to reload. What should the developer implement?

   • AUse a patch operation to update only the changed properties.
   • BUse a stored procedure to update the document without any concurrency check.
   • CUse ReplaceItemAsync with the ETag from the original read in the IfMatch option.
   • DUse a query to check the last modified time before updating.
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4. 43application · medium

   A multi-tier web application uses Azure Cosmos DB for NoSQL. The account is configured with session consistency. A user updates their profile, and then immediately refreshes the page to view the changes. The web app uses multiple backend instances behind a load balancer. The team wants to ensure that the user always sees their own recent writes, even if the read request is handled by a different backend instance. What should they do?

   • AChange the account consistency to Strong to guarantee all reads see the latest write.
   • BEnsure that the session token from the write is passed in the request options for subsequent reads.
   • CUse a point read with the ETag from the write operation.
   • DUse a query with a continuation token from the write operation.
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5. 44application · medium

   A healthcare application uses Azure Cosmos DB for NoSQL to store patient records. Two microservices can update the same patient record concurrently. The team needs to ensure that one service does not overwrite changes made by the other. They also want to avoid the overhead of locking the record for the entire update. Which SDK feature should they use?

   • AUse optimistic concurrency control by passing the ETag of the item in the request options for replace operations.
   • BUse a transactional batch to wrap both updates in a single atomic operation.
   • CUse the Bulk SDK to send both updates in the same batch.
   • DUse a stored procedure to perform the update, which runs atomically on the server.
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6. 45foundation · easy

   Which Azure Cosmos DB for NoSQL SDK method is used to create a new item in a container?

   • AReplaceItemAsync
   • BUpsertItemAsync
   • CReadItemAsync
   • DCreateItemAsync
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