Google Google Certifications PROFESSIONAL-CLOUD-DATABASE-ENGINEER Questions & Answers

• Question 21:

  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?

  A. Set up a Shared VPC, configure multiple service projects, and create firewall rules.

  B. Set up Serverless VPC Access.

  C. Set up Private Service Connect.

  D. Set up Traffic Director.

  Correct Answer: A

• Question 22:

  You are the DBA of an online tutoring application that runs on a Cloud SQL for PostgreSQL database. You are testing the implementation of the cross-regional failover configuration. The database in region R1 fails over successfully to region R2, and the database becomes available for the application to process data. During testing, certain scenarios of the application work as expected in region R2, but a few scenarios fail with database errors. The application-related database queries, when executed in isolation from Cloud SQL for PostgreSQL in region R2, work as expected. The application performs completely as expected when the database fails back to region R1. You need to identify the cause of the database errors in region R2. What should you do?

  A. Determine whether the versions of Cloud SQL for PostgreSQL in regions R1 and R2 are different.

  B. Determine whether the database patches of Cloud SQI for PostgreSQL in regions R1 and R2 are different.

  C. Determine whether the failover of Cloud SQL for PostgreSQL from region R1 to region R2 is in progress or has completed successfully.

  D. Determine whether Cloud SQL for PostgreSQL in region R2 is a near-real-time copy of region R1 but not an exact copy.

  Correct Answer: D

  Verify that the replica has processed all the transactions it has received from the primary. This ensures that when promoted, the replica reflects all transactions that were received before the primary became unavailable. https://cloud.google.com/sql/docs/postgres/replication/cross-region-replicas#verify_failover_criteria

• Question 23:

  You are migrating an on-premises application to Google Cloud. The application requires a high availability (HA) PostgreSQL database to support business-critical functions. Your company's disaster recovery strategy requires a recovery time objective (RTO) and recovery point objective (RPO) within 30 minutes of failure. You plan to use a Google Cloud managed service. What should you do to maximize uptime for your application?

  A. Deploy Cloud SQL for PostgreSQL in a regional configuration. Create a read replica in a different zone in the same region and a read replica in another region for disaster recovery.

  B. Deploy Cloud SQL for PostgreSQL in a regional configuration with HA enabled. Take periodic backups, and use this backup to restore to a new Cloud SQL for PostgreSQL instance in another region during a disaster recovery event.

  C. Deploy Cloud SQL for PostgreSQL in a regional configuration with HA enabled. Create a cross-region read replica, and promote the read replica as the primary node for disaster recovery.

  D. Migrate the PostgreSQL database to multi-regional Cloud Spanner so that a single region outage will not affect your application. Update the schema to support Cloud Spanner data types, and refactor the application.

  Correct Answer: C

  The best answer is deploy an HA configuration and have a read replica you could promote to the primary in a different region

• Question 24:

  Your organization is running a MySQL workload in Cloud SQL. Suddenly you see a degradation in database performance. You need to identify the root cause of the performance degradation. What should you do?

  A. Use Logs Explorer to analyze log data.

  B. Use Cloud Monitoring to monitor CPU, memory, and storage utilization metrics.

  C. Use Error Reporting to count, analyze, and aggregate the data.

  D. Use Cloud Debugger to inspect the state of an application.

  Correct Answer: B

• Question 25:

  You are managing a set of Cloud SQL databases in Google Cloud. Regulations require that database backups reside in the region where the database is created. You want to minimize operational costs and administrative effort. What should you do?

  A. Configure the automated backups to use a regional Cloud Storage bucket as a custom location.

  B. Use the default configuration for the automated backups location.

  C. Disable automated backups, and create an on-demand backup routine to a regional Cloud Storage bucket.

  D. Disable automated backups, and configure serverless exports to a regional Cloud Storage bucket.

  Correct Answer: A

  https://cloud.google.com/sql/docs/mysql/backup-recovery/backing-up#locationbackups You can use a custom location for on-demand and automatic backups. For a complete list of valid location values, see the Instance locations.

• Question 26:

  Your DevOps team is using Terraform to deploy applications and Cloud SQL databases. After every new application change is rolled out, the environment is torn down and recreated, and the persistent database layer is lost. You need to prevent the database from being dropped. What should you do?

  A. Set Terraform deletion_protection to true.

  B. Rerun terraform apply.

  C. Create a read replica.

  D. Use point-in-time-recovery (PITR) to recover the database.

  Correct Answer: A

  From Google's documentation, "For stateful resources, such as databases, ensure that deletion protection is enabled. The syntax is: lifecycle { prevent_destroy = true } https://cloud.google.com/docs/terraform/best-practices-forterraform#stateful-resources

• Question 27:

  Your organization deployed a new version of a critical application that uses Cloud SQL for MySQL with high availability (HA) and binary logging enabled to store transactional information. The latest release of the application had an error that caused massive data corruption in your Cloud SQL for MySQL database. You need to minimize data loss. What should you do?

  A. Open the Google Cloud Console, navigate to SQL > Backups, and select the last version of the automated backup before the corruption.

  B. Reload the Cloud SQL for MySQL database using the LOAD DATA command to load data from CSV files that were used to initialize the instance.

  C. Perform a point-in-time recovery of your Cloud SQL for MySQL database, selecting a date and time before the data was corrupted.

  D. Fail over to the Cloud SQL for MySQL HA instance. Use that instance to recover the transactions that occurred before the corruption.

  Correct Answer: C

  Binary Logging enabled, with that you can identify the point of time the data was good and recover from that point time. https://cloud.google.com/sql/docs/mysql/backup-recovery/pitr#perform_the_point-in-time_recovery_using_binary_log_positions

• Question 28:

  You are designing a database architecture for a global application that stores information about public parks worldwide. The application uses the database for read-only purposes, and a centralized batch job updates the database nightly. You want to select an open source, SQL-compliant database. What should you do?

  A. Use Bigtable with multi-region clusters.

  B. Use Memorystore for Redis with multi-zones within a region.

  C. Use Cloud SQL for PostgreSQL with cross-region replicas.

  D. Use Cloud Spanner with multi-region configuration.

  Correct Answer: C

• Question 29:

  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?

  A. Use Firestore.

  B. Use Cloud SQL with an external (public) IP address.

  C. Use an in-app embedded database.

  D. Use Cloud Spanner.

  Correct Answer: A

  https://firebase.google.com/docs/firestore

• Question 30:

  You want to migrate your on-premises PostgreSQL database to Compute Engine. You need to migrate this database with the minimum downtime possible. What should you do?

  A. Perform a full backup of your on-premises PostgreSQL, and then, in the migration window, perform an incremental backup.

  B. Create a read replica on Cloud SQL, and then promote it to a read/write standalone instance.

  C. Use Database Migration Service to migrate your database.

  D. Create a hot standby on Compute Engine, and use PgBouncer to switch over the connections.

  Correct Answer: D

  PgBouncer maintains a pool for connections for each database and user combination. PgBouncer either creates a new database connection for a client or reuses an existing connection for the same user and database. + PgBouncer is a simple PostgreSQL connection pool that allows for several thousand connections at a time. Using Kubernetes Engine to run a Helm Chart w/ PgBouncer based on the great article from futuretech-industries, we were able to set up an easily deployable system to get the most out of our CloudSQL DBs without breaking the bank. https://medium.com/google-cloud/increasing-cloud-sql-postgresql-max-connections-w-pgbouncer-kubernetes-engine-49b0b2894820#:~:text=That%20is %20where,breaking%20the%20bank.