Microsoft Microsoft Certified: Azure Cosmos DB Developer Specialty DP-420 Questions & Answers

• Question 11:

  You have a container in an Azure Cosmos DB Core (SQL) API account. The container stores telemetry data from IoT devices. The container uses telemetryId as the partition key and has a throughput of 1,000 request units per second (RU/s).

  Approximately 5,000 IoT devices submit data every five minutes by using the same telemetryId value.

  You have an application that performs analytics on the data and frequently reads telemetry data for a single IoT device to perform trend analysis.

  The following is a sample of a document in the container.

  

  You need to reduce the amount of request units (RUs) consumed by the analytics application. What should you do?

  A. Decrease the offerThroughputvalue for the container.

  B. Increase the offerThroughputvalue for the container.

  C. Move the data to a new container that has a partition key of deviceId.

  D. Move the data to a new container that uses a partition key of date.

  Correct Answer: C

  The partition key is what will determine how data is routed in the various partitions by Cosmos DB and needs to make sense in the context of your specific scenario. The IoT Device ID is generally the "natural" partition key for IoT applications.

  Reference: https://docs.microsoft.com/en-us/azure/architecture/solution-ideas/articles/iot-using-cosmos-db

• Question 12:

  You maintain a relational database for a book publisher. The database contains the following tables.

  

  The most common query lists the books for a given authorId.

  You need to develop a non-relational data model for Azure Cosmos DB Core (SQL) API that will replace the relational database. The solution must minimize latency and read operation costs.

  What should you include in the solution?

  A. Create a container for Author and a container for Book. In each Author document, embed bookId for each book by the author. In each Book document embed authorIdof each author.

  B. Create Author, Book, and Bookauthorlnk documents in the same container.

  C. Create a container that contains a document for each Author and a document for each Book. In each Book document, embed authorId.

  D. Create a container for Author and a container for Book. In each Author document and Book document embed the data from Bookauthorlnk.

  Correct Answer: A

  Store multiple entity types in the same container.

• Question 13:

  The settings for a container in an Azure Cosmos DB Core (SQL) API account are configured as shown in the following exhibit.

  

  Which statement describes the configuration of the container?

  A. All items will be deleted after one year.

  B. Items stored in the collection will be retained always, regardless of the items time to live value.

  C. Items stored in the collection will expire only if the item has a time to live value.

  D. All items will be deleted after one hour.

  Correct Answer: C

  When DefaultTimeToLive is -1 then your Time to Live setting is On (No default)

  Time to Live on a container, if present and the value is set to "-1", it is equal to infinity, and items don't expire by default.

  Time to Live on an item:

  This Property is applicable only if DefaultTimeToLive is present and it is not set to null for the parent container.

  If present, it overrides the DefaultTimeToLive value of the parent container.

  Reference:

  https://docs.microsoft.com/en-us/azure/cosmos-db/sql/time-to-live

• Question 14:

  After you answer a question in this section, you will NOT be able to return to it. As a result, these questions will not appear in the review screen.

  You have an Azure Cosmos DB Core (SQL) API account named account 1 that uses autoscale throughput.

  You need to run an Azure function when the normalized request units per second for a container in account1 exceeds a specific value.

  Solution: You configure the function to have an Azure CosmosDB trigger.

  Does this meet the goal?

  A. Yes

  B. No

  Correct Answer: B

  Instead configure an Azure Monitor alert to trigger the function.

  You can set up alerts from the Azure Cosmos DB pane or the Azure Monitor service in the Azure portal.

  Reference:

  https://docs.microsoft.com/en-us/azure/cosmos-db/create-alerts

• Question 15:

  After you answer a question in this section, you will NOT be able to return to it. As a result, these questions will not appear in the review screen.

  You have a container named container1 in an Azure Cosmos DB Core (SQL) API account.

  You need to make the contents of container1 available as reference data for an Azure Stream Analytics job.

  Solution: You create an Azure function that uses Azure Cosmos DB Core (SQL) API change feed as a trigger and Azure event hub as the output.

  Does this meet the goal?

  A. Yes

  B. No

  Correct Answer: B

  The Azure Cosmos DB change feed is a mechanism to get a continuous and incremental feed of records from an Azure Cosmos container as those records are being created or modified. Change feed support works by listening to container for any changes. It then outputs the sorted list of documents that were changed in the order in which they were modified.

  Reference: https://docs.microsoft.com/en-us/azure/cosmos-db/sql/changefeed-ecommerce-solution

• Question 16:

  After you answer a question in this section, you will NOT be able to return to it. As a result, these questions will not appear in the review screen.

  You have a container named container1 in an Azure Cosmos DB Core (SQL) API account.

  You need to make the contents of container1 available as reference data for an Azure Stream Analytics job.

  Solution: You create an Azure Data Factory pipeline that uses Azure Cosmos DB Core (SQL) API as the input and Azure Blob Storage as the output.

  Does this meet the goal?

  A. Yes

  B. No

  Correct Answer: B

  Instead create an Azure function that uses Azure Cosmos DB Core (SQL) API change feed as a trigger and Azure event hub as the output.

  The Azure Cosmos DB change feed is a mechanism to get a continuous and incremental feed of records from an Azure Cosmos container as those records are being created or modified. Change feed support works by listening to container for any changes. It then outputs the sorted list of documents that were changed in the order in which they were modified.

  Reference: https://docs.microsoft.com/en-us/azure/cosmos-db/sql/changefeed-ecommerce-solution

• Question 17:

  After you answer a question in this section, you will NOT be able to return to it. As a result, these questions will not appear in the review screen.

  You have a container named container1 in an Azure Cosmos DB Core (SQL) API account.

  You need to make the contents of container1 available as reference data for an Azure Stream Analytics job.

  Solution: You create an Azure Synapse pipeline that uses Azure Cosmos DB Core (SQL) API as the input and Azure Blob Storage as the output.

  Does this meet the goal?

  A. Yes

  B. No

  Correct Answer: B

  Instead create an Azure function that uses Azure Cosmos DB Core (SQL) API change feed as a trigger and Azure event hub as the output.

  The Azure Cosmos DB change feed is a mechanism to get a continuous and incremental feed of records from an Azure Cosmos container as those records are being created or modified. Change feed support works by listening to container for any changes. It then outputs the sorted list of documents that were changed in the order in which they were modified.

  Reference: https://docs.microsoft.com/en-us/azure/cosmos-db/sql/changefeed-ecommerce-solution

• Question 18:

  You need to implement a trigger in Azure Cosmos DB Core (SQL) API that will run before an item is inserted into a container. Which two actions should you perform to ensure that the trigger runs? Each correct answer presents part of the solution. NOTE: Each correct selection is worth one point.

  A. Append pre to the name of the JavaScript function trigger.

  B. For each create request, set the access condition in RequestOptions.

  C. Register the trigger as a pre-trigger.

  D. For each create request, set the consistency level to session in RequestOptions.

  E. For each create request, set the trigger name in RequestOptions.

  Correct Answer: C

  C: When triggers are registered, you can specify the operations that it can run with.

  F: When executing, pre-triggers are passed in the RequestOptions object by specifying PreTriggerInclude and then passing the name of the trigger in a List object.

  Reference: https://docs.microsoft.com/en-us/azure/cosmos-db/sql/how-to-use-stored-procedures-triggers-udfs

• Question 19:

  You have an Azure Cosmos DB Core (SQL) API account.

  You run the following query against a container in the account.

  SELECT

  IS_NUMBER("1234") AS A,

  IS_NUMBER(1234) AS B,

  IS_NUMBER({prop: 1234}) AS C

  What is the output of the query?

  A. [{"A": false, "B": true, "C": false}]

  B. [{"A": true, "B": false, "C": true}]

  C. [{"A": true, "B": true, "C": false}]

  D. [{"A": true, "B": true, "C": true}]

  Correct Answer: A

  IS_NUMBER returns a Boolean value indicating if the type of the specified expression is a number. "1234" is a string, not a number.

  Reference: https://docs.microsoft.com/en-us/azure/cosmos-db/sql/sql-query-is-number

• Question 20:

  The following is a sample of a document in orders.

  

  The orders container uses customerIdas the partition key.

  You need to provide a report of the total items ordered per month by item type. The solution must meet the following requirements:

  1.

  Ensure that the report can run as quickly as possible.

  2.

  Minimize the consumption of request units (RUs). What should you do?

  A. Configure the report to query orders by using a SQL query.

  B. Configure the report to query a new aggregate container. Populate the aggregates by using the change feed.

  C. Configure the report to query orders by using a SQL query through a dedicated gateway.

  D. Configure the report to query a new aggregate container. Populate the aggregates by using SQL queries that run daily.

  Correct Answer: B

  You can facilitate aggregate data by using Change Feed and Azure Functions, and then use it for reporting.

  Reference: https://docs.microsoft.com/en-us/azure/cosmos-db/change-feed