PCDBE practice questions 61–70

1. Question 61 · 170 in bank

   You are building an Android game that needs to store data on a Google Cloud serverless database. The database will log user activity, store user preferences, and receive in-game updates. The target audience resides in developing countries that have intermittent internet connectivity. You need to ensure that the game can synchronize game data to the backend database whenever an internet network is available. What should you do?

   • AUse Firestore.
   • BUse Cloud SQL with an external (public) IP address.
   • CUse an in-app embedded database.
   • DUse Cloud Spanner.

   Show answer

   Answer: A

   Explanation

   A. B is wrong since that’s not secure and doesn’t make sense. C is bizarre and doesn’t leverage a GCP serverless database. The key is intermittent internet coverage, meaning real-time syncing is not needed and can be supported. That rules out Spanner, which leaves Firestore. Probably Datastore mode, not that the question mentions that. The link provided by GCP72 is spot on.

   Source: Adapted from community discussion — dynamic_dba

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2. Question 62 · 170 in bank

   Select 2

   You released a popular mobile game and are using a 50 TB Cloud Spanner instance to store game data in a PITR-enabled production environment. When you analyzed the game statistics, you realized that some players are exploiting a loophole to gather more points to get on the leaderboard. Another DBA accidentally ran an emergency bugfix script that corrupted some of the data in the production environment. You need to determine the extent of the data corruption and restore the production environment. What should you do? (Choose two.)

   • AIf the corruption is significant, use backup and restore, and specify a recovery timestamp.
   • BIf the corruption is significant, perform a stale read and specify a recovery timestamp. Write the results back.
   • CIf the corruption is significant, use import and export.
   • DIf the corruption is insignificant, use backup and restore, and specify a recovery timestamp.
   • EIf the corruption is insignificant, perform a stale read and specify a recovery timestamp. Write the results back.

   Show answer

   Answer: AE

   Explanation

   https://cloud.google.com/spanner/docs/pitr#ways-to-recover To recover the entire database, backup or export the database specifying a timestamp in the past and then restore or import it to a new database. This is typically used to recover from data corruption issues when you have to revert the entire database to a point-in-time before the corruption occurred. This part describes significant corruption - A To recover a portion of the database, perform a stale read specifying a query-condition and timestamp in the past, and then write the results back into the live database. This is typically used for surgical operations on a live database. For example, if you accidentally delete a particular row or incorrectly update a subset of data, you can recover it with this method. This describes insignificant corruption case - E

   Source: Adapted from community discussion — chelbsik

   References

   • Google Cloud documentation
   • Google Cloud documentation

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3. Question 63 · 170 in bank

   You are starting a large CSV import into a Cloud SQL for MySQL instance that has many open connections. You checked memory and CPU usage, and sufficient resources are available. You want to follow Google-recommended practices to ensure that the import will not time out. What should you do?

   • AClose idle connections or restart the instance before beginning the import operation.
   • BIncrease the amount of memory allocated to your instance.
   • CEnsure that the service account has the Storage Admin role.
   • DIncrease the number of CPUs for the instance to ensure that it can handle the additional import operation.

   Show answer

   Answer: A

   Explanation

   The import operation is taking too long. Too many active connections can interfere with import operations. Close unused operations. Check the CPU and memory usage of your Cloud SQL instance to make sure there are plenty of resources available. The best way to ensure maximum resources for the import is to restart the instance before beginning the operation. A restart: Closes all connections. Ends any tasks that may be consuming resources https://cloud.google.com/sql/docs/mysql/import-export

   Source: Adapted from community discussion — GCP72

   References

   • Google Cloud documentation
   • Google Cloud documentation

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4. Question 64 · 170 in bank

   You are migrating your data center to Google Cloud. You plan to migrate your applications to Compute Engine and your Oracle databases to Bare Metal Solution for Oracle. You must ensure that the applications in different projects can communicate securely and efficiently with the Oracle databases. What should you do?

   • ASet up a Shared VPC, configure multiple service projects, and create firewall rules.
   • BSet up Serverless VPC Access.
   • CSet up Private Service Connect.
   • DSet up Traffic Director.

   Show answer

   Answer: A

   Explanation

   B is not applicable here. C is also not the case - don't confuse it with Private Google Access https://cloud.google.com/bare-metal/docs/bms-security#enforce-a-secure-perimeter-with-private-google-access We don't have a Service Mesh here, so D is also not an option. I go for A - https://cloud.google.com/bare-metal/docs/bms-security#:~:text=As%20shown%20in%20Figure%206%2C%20use%20a%20shared%20VPC%20architecture%20to%20allow%20resources%20from%20different%20projects%20to%20access%20the%20Bare%20Metal%20Solution%20servers

   Source: Adapted from community discussion — chelbsik

   References

   • Google Cloud documentation

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5. Question 65 · 170 in bank

   You are running an instance of Cloud Spanner as the backend of your ecommerce website. You learn that the quality assurance (QA) team has doubled the number of their test cases. You need to create a copy of your Cloud Spanner database in a new test environment to accommodate the additional test cases. You want to follow Google-recommended practices. What should you do?

   • AUse Cloud Functions to run the export in Avro format.
   • BUse Cloud Functions to run the export in text format.
   • CUse Dataflow to run the export in Avro format.
   • DUse Dataflow to run the export in text format.

   Show answer

   Answer: C

   Explanation

   C. A and B are wrong because Spanner exports are run as Dataflow jobs. The question says you need a copy of your entire database which means all the tables. You cannot export an entire database using the CSV (text) format, but you can using the Avro format. So that would make it the better option. https://cloud.google.com/spanner/docs/import-export-overview#file-format

   Source: Adapted from community discussion — dynamic_dba

   References

   • Google Cloud documentation
   • Google Cloud documentation

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6. Question 66 · 170 in bank

   Your customer has a global chat application that uses a multi-regional Cloud Spanner instance. The application has recently experienced degraded performance after a new version of the application was launched. Your customer asked you for assistance. During initial troubleshooting, you observed high read latency. What should you do?

   • AUse query parameters to speed up frequently executed queries.
   • BChange the Cloud Spanner configuration from multi-region to single region.
   • CUse SQL statements to analyze SPANNER_SYS.READ_STATS* tables.
   • DUse SQL statements to analyze SPANNER_SYS.QUERY_STATS* tables.

   Show answer

   Answer: C

   Explanation

   Read statistics provide insight into how an application is using the database, and are useful when investigating performance issues. https://cloud.google.com/spanner/docs/introspection/read-statistics

   Source: Adapted from community discussion — jnya_1991

   References

   • Google Cloud documentation

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7. Question 67 · 170 in bank

   You need to redesign the architecture of an application that currently uses Cloud SQL for PostgreSQL. The users of the application complain about slow query response times. You want to enhance your application architecture to offer sub-millisecond query latency. What should you do?

   • AConfigure Firestore, and modify your application to offload queries.
   • BConfigure Bigtable, and modify your application to offload queries.
   • CConfigure Cloud SQL for PostgreSQL read replicas to offload queries.
   • DConfigure Memorystore, and modify your application to offload queries.

   Show answer

   Answer: D

   Explanation

   The question says "redesign the architecture of an application" - Caching data using MemoryStore will trigger this. Read replica will require only updating connection details which would not be considered an application redesign.

   Source: Adapted from community discussion — csrazdan

   References

   • Google Cloud documentation

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8. Question 68 · 170 in bank

   You need to migrate existing databases from Microsoft SQL Server 2016 Standard Edition on a single Windows Server 2019 Datacenter Edition to a single Cloud SQL for SQL Server instance. During the discovery phase of your project, you notice that your on-premises server peaks at around 25,000 read IOPS. You need to ensure that your Cloud SQL instance is sized appropriately to maximize read performance. What should you do?

   • ACreate a SQL Server 2019 Standard on Standard machine type with 4 vCPUs, 15 GB of RAM, and 800 GB of solid-state drive (SSD).
   • BCreate a SQL Server 2019 Standard on High Memory machine type with at least 16 vCPUs, 104 GB of RAM, and 200 GB of SSD.
   • CCreate a SQL Server 2019 Standard on High Memory machine type with 16 vCPUs, 104 GB of RAM, and 4 TB of SSD.
   • DCreate a SQL Server 2019 Enterprise on High Memory machine type with 16 vCPUs, 104 GB of RAM, and 500 GB of SSD.

   Show answer

   Answer: C

   Explanation

   Given that Google SSD performance is related to the size of the disk in an order of 30 IOPS for each GB, ti would require at least 833 GB to handle 25000 IOPS, the only answer that exceeds this value is C. https://cloud.google.com/compute/docs/disks/performance

   Source: Adapted from community discussion — fredcaram

   References

   • Google Cloud documentation
   • Google Cloud documentation

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9. Question 69 · 170 in bank

   You are managing a small Cloud SQL instance for developers to do testing. The instance is not critical and has a recovery point objective (RPO) of several days. You want to minimize ongoing costs for this instance. What should you do?

   • ATake no backups, and turn off transaction log retention.
   • BTake one manual backup per day, and turn off transaction log retention.
   • CTurn on automated backup, and turn off transaction log retention.
   • DTurn on automated backup, and turn on transaction log retention.

   Show answer

   Answer: C

   Explanation

   C. A is wrong since there is an RPO. B requires manual intervention which partly defeats the object of using a managed service like Cloud SQL. D is wrong since retaining transaction logs would permit point-in-time recovery which is not required. That leaves C.

   Source: Adapted from community discussion — dynamic_dba

   References

   • Google Cloud documentation

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10. Question 70 · 170 in bank

    You manage a meeting booking application that uses Cloud SQL. During an important launch, the Cloud SQL instance went through a maintenance event that resulted in a downtime of more than 5 minutes and adversely affected your production application. You need to immediately address the maintenance issue to prevent any unplanned events in the future. What should you do?

    • ASet your production instance's maintenance window to non-business hours.
    • BMigrate the Cloud SQL instance to Cloud Spanner to avoid any future disruptions due to maintenance.
    • CContact Support to understand why your Cloud SQL instance had a downtime of more than 5 minutes.
    • DUse Cloud Scheduler to schedule a maintenance window of no longer than 5 minutes.

    Show answer

    Answer: A

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PCDBE practice, question 61. 170 questions available.