Professional Cloud Database Engineer Practice Exam

Are you preparing to become a certified Professional Cloud Database Engineer? This comprehensive practice exam from Exam Sage is designed to help you master the key concepts, technologies, and skills needed to pass the official certification with confidence.

What Is the Professional Cloud Database Engineer Exam?

The Professional Cloud Database Engineer certification validates your expertise in designing, building, and managing scalable, highly available, and secure cloud-native database solutions on Google Cloud Platform (GCP). This exam tests your knowledge of various managed database services, data modeling, query optimization, database migration, security best practices, and performance tuning in a cloud environment.

What You Will Learn

By practicing with this Exam Sage test, you will gain a deep understanding of:

Core Google Cloud database products such as Cloud Spanner, Cloud Bigtable, Cloud SQL, and BigQuery.
Designing efficient and scalable database schemas tailored for specific workloads.
Data migration strategies to transition on-premises databases to Google Cloud smoothly.
Optimizing database performance and ensuring high availability.
Implementing security controls, including access management and encryption.
Querying and managing large datasets with BigQuery and understanding cost management.
Managing data consistency, replication, and backup strategies.
Troubleshooting and monitoring databases using Google Cloud tools.

Each question in this practice exam is carefully crafted to mirror the complexity and format of the real certification exam. Detailed explanations accompany every answer, allowing you to understand not just what the correct response is but why it’s correct — a crucial step for effective learning.

Topics Covered

This practice exam covers the following essential topics:

Google Cloud database products overview and selection criteria
Schema design and data modeling best practices
Cloud database security and compliance requirements
Migration and integration strategies
Query optimization and cost control techniques
Backup, recovery, and disaster recovery planning
Performance tuning and monitoring
Data consistency and replication models

Why Choose Exam Sage for Your Cloud Database Engineer Exam Preparation?

Exam Sage is a trusted platform committed to providing high-quality, up-to-date exam preparation materials. Our practice exams are created by subject-matter experts and are regularly updated to reflect the latest exam objectives and industry standards.

With Exam Sage, you get:

Realistic practice questions designed to build confidence and reduce exam anxiety.
Clear, concise explanations that deepen your understanding.
Flexible learning that fits your schedule — practice anytime, anywhere.
A user-friendly platform that tracks your progress and highlights areas needing improvement.

Preparing for the Professional Cloud Database Engineer exam can be challenging, but with Exam Sage’s comprehensive practice tests, you’ll gain the knowledge and skills to succeed. Whether you’re a database professional, cloud engineer, or IT specialist, this practice exam will help you demonstrate your cloud database expertise and advance your career.

Sample Questions and Answers

1. You are tasked with migrating a PostgreSQL database from on-premises to Google Cloud. Which service provides the best managed solution with minimal operational overhead?

A. Compute Engine
B. Cloud SQL
C. Cloud Bigtable
D. Firestore

Answer: B. Cloud SQL
Explanation: Cloud SQL offers a fully managed relational database service for PostgreSQL, MySQL, and SQL Server. It handles backups, patching, and replication.

2. Which storage solution is optimal for storing and querying massive amounts of time-series data in Google Cloud?

A. Cloud SQL
B. BigQuery
C. Cloud Bigtable
D. Datastore

Answer: C. Cloud Bigtable
Explanation: Cloud Bigtable is ideal for high-throughput workloads like time-series data due to its low latency and scalability.

3. A customer wants to build a financial dashboard that runs complex, ad-hoc SQL queries on petabyte-scale datasets. What should you recommend?

A. Cloud Spanner
B. Cloud SQL
C. BigQuery
D. Cloud Datastore

Answer: C. BigQuery
Explanation: BigQuery is a serverless, highly scalable analytics data warehouse ideal for big data and ad-hoc queries.

4. Which service is NOT a fully managed database service on GCP?

A. Cloud SQL
B. Cloud Spanner
C. Compute Engine with MySQL
D. Firestore

Answer: C. Compute Engine with MySQL
Explanation: Running MySQL on Compute Engine requires user management of backups, patching, and failover, hence not fully managed.

5. You are designing a global application that requires high availability and strong consistency. Which GCP service is best suited?

A. BigQuery
B. Cloud Spanner
C. Cloud SQL
D. Datastore

Answer: B. Cloud Spanner
Explanation: Cloud Spanner is a globally distributed, strongly consistent relational database ideal for mission-critical applications.

6. You need a NoSQL document database for a mobile app. Which GCP service should you choose?

A. Cloud SQL
B. Firestore
C. BigQuery
D. Cloud Spanner

Answer: B. Firestore
Explanation: Firestore is a NoSQL document database optimized for mobile and real-time applications.

7. What is the recommended way to achieve high availability with Cloud SQL?

A. Multi-zone instance
B. Read replicas
C. Multi-regional replication
D. Standby failover instance

Answer: D. Standby failover instance
Explanation: High availability in Cloud SQL is achieved using a standby instance in a different zone, enabling automatic failover.

8. Which GCP service offers ANSI SQL support for data warehousing?

A. Cloud Spanner
B. BigQuery
C. Cloud SQL
D. Firestore

Answer: B. BigQuery
Explanation: BigQuery supports ANSI SQL for querying large datasets and is ideal for data warehouse use cases.

9. Your company needs to store semi-structured JSON data and supports ACID transactions. Which GCP service should you use?

A. Bigtable
B. Firestore
C. BigQuery
D. Cloud Storage

Answer: B. Firestore
Explanation: Firestore is suitable for semi-structured data and supports multi-document ACID transactions.

10. Cloud Spanner’s unique selling point is:

A. Horizontal scalability and eventual consistency
B. Global consistency and strong ACID compliance
C. Support for only NoSQL workloads
D. Single-region deployments only

Answer: B. Global consistency and strong ACID compliance
Explanation: Cloud Spanner provides horizontal scalability along with strong consistency and relational schema support.

11. Which command-line tool is typically used for interacting with GCP databases and other services?

A. mysql-cli
B. psql
C. gcloud
D. bq

Answer: C. gcloud
Explanation: gcloud is the primary CLI for managing Google Cloud resources, including databases.

12. How does Cloud SQL provide automatic backups?

A. Through a scheduled cron job
B. By using Cloud Functions
C. Configurable daily backups
D. Through user scripts only

Answer: C. Configurable daily backups
Explanation: Cloud SQL allows automated daily backups that can be configured by the user.

13. A developer needs to store large binary objects (BLOBs). Which GCP service should they use?

A. Cloud SQL
B. Firestore
C. Cloud Storage
D. Bigtable

Answer: C. Cloud Storage
Explanation: Cloud Storage is ideal for storing BLOBs, including videos, images, and large files.

14. What is the maximum size of a BigQuery table?

A. 1 TB
B. 10 TB
C. 100 TB
D. No fixed limit

Answer: D. No fixed limit
Explanation: BigQuery scales seamlessly and doesn’t impose strict table size limits, only practical project quotas.

15. Which GCP database service is best for online transaction processing (OLTP)?

A. Cloud Spanner
B. BigQuery
C. Cloud Storage
D. Cloud Functions

Answer: A. Cloud Spanner
Explanation: Cloud Spanner is optimized for OLTP workloads with high availability and consistency.

16. Cloud Bigtable is based on which open-source technology?

A. MongoDB
B. Apache HBase
C. MySQL
D. Cassandra

Answer: B. Apache HBase
Explanation: Cloud Bigtable is a managed implementation based on the Apache HBase model.

17. You want to encrypt your Cloud SQL data at rest using your own encryption keys. What should you use?

A. Default Google-managed encryption
B. Cloud KMS with CMEK
C. IAM roles
D. gcloud encryption API

Answer: B. Cloud KMS with CMEK
Explanation: CMEK (Customer Managed Encryption Keys) with Cloud KMS allows users to manage their own encryption keys.

18. Which feature allows BigQuery to analyze data directly from Cloud Storage without loading it?

A. Federated queries
B. Transfer Service
C. Partitioned tables
D. Datalab

Answer: A. Federated queries
Explanation: Federated queries let BigQuery analyze external data sources like Cloud Storage without loading them into BigQuery.

19. What does “high throughput” in Cloud Bigtable mean?

A. Low disk usage
B. Many concurrent writes/reads per second
C. Low-cost storage
D. Fast analytics

Answer: B. Many concurrent writes/reads per second
Explanation: Cloud Bigtable supports high read/write throughput, making it ideal for telemetry, IoT, and similar workloads.

20. What storage type does BigQuery use to store data?

A. Row-based
B. Columnar
C. Key-value
D. Object

Answer: B. Columnar
Explanation: BigQuery uses a columnar storage format, which is optimal for analytical queries.

21. What is the best way to export Cloud SQL data regularly to GCS?

A. Use mysqldump manually
B. Create a read replica and export
C. Use Cloud Scheduler with export job
D. Use Cloud Functions

Answer: C. Use Cloud Scheduler with export job
Explanation: You can schedule automated exports to GCS using Cloud Scheduler combined with SQL Admin API.

22. You want to perform a rolling schema update in Cloud Spanner with no downtime. What should you do?

A. Disable all client connections
B. Use DDL statements in a transaction
C. Apply changes incrementally using versioned columns
D. Export and re-import the database

Answer: C. Apply changes incrementally using versioned columns
Explanation: Rolling schema updates involve backward-compatible changes with versioning to avoid downtime.

23. Firestore supports which types of querying capabilities?

A. Only key-based
B. Ad-hoc JOINs
C. Structured queries with compound filters
D. SQL-like subqueries

Answer: C. Structured queries with compound filters
Explanation: Firestore supports compound filtering and range queries but not SQL joins or subqueries.

24. Which GCP service provides millisecond-latency for real-time analytics?

A. BigQuery
B. Firestore
C. Cloud SQL
D. Bigtable

Answer: D. Bigtable
Explanation: Bigtable offers low-latency access suitable for real-time analytics and dashboarding.

25. You are designing a system that must auto-scale based on traffic. Which GCP database supports horizontal scaling natively?

A. Cloud SQL
B. Cloud Spanner
C. Firestore in Native Mode
D. BigQuery

Answer: B. Cloud Spanner
Explanation: Cloud Spanner supports horizontal scaling with strong consistency and ACID transactions.

26. What are BigQuery slots?

A. Memory units
B. Billing units
C. Virtual CPUs for processing queries
D. Storage blocks

Answer: C. Virtual CPUs for processing queries
Explanation: Slots are virtual CPUs used by BigQuery to execute SQL queries.

27. Which Google Cloud service provides relational database capabilities and supports horizontal scaling and global distribution?

A. Cloud SQL
B. Cloud Spanner
C. BigQuery
D. Firestore

Answer: B. Cloud Spanner
Explanation: Cloud Spanner combines relational database features with horizontal scale and global distribution.

28. Which database offers real-time change streams (CDC) in Firestore?

A. Cloud SQL
B. Cloud Spanner
C. Firestore
D. BigQuery

Answer: C. Firestore
Explanation: Firestore supports real-time updates using listeners and streams, ideal for live apps.

29. Which statement about BigQuery pricing is true?

A. You pay per row
B. You are charged per CPU usage
C. You are charged per TB queried
D. Pricing is fixed monthly

Answer: C. You are charged per TB queried
Explanation: BigQuery charges based on the amount of data processed by queries (per TB).

30. You are implementing a multi-cloud solution. Which GCP service supports cross-cloud relational data synchronization with minimal effort?

A. Cloud SQL
B. Cloud Spanner
C. Datastream
D. Firestore

Answer: C. Datastream
Explanation: Datastream is a serverless change data capture and replication service ideal for hybrid and multi-cloud scenarios.

31. You need to migrate a large MySQL database from on-premises to Google Cloud with minimal downtime. Which service should you use?

A. Cloud SQL import
B. Cloud SQL export
C. Database Migration Service (DMS)
D. Dataflow

Answer: C. Database Migration Service (DMS)
Explanation: DMS provides a serverless, secure, and easy-to-use migration experience for MySQL and PostgreSQL databases to Cloud SQL with minimal downtime.

32. Which GCP service is best suited for storing and querying large volumes of time-series data?

A. Cloud SQL
B. BigQuery
C. Cloud Bigtable
D. Firestore

Answer: C. Cloud Bigtable
Explanation: Cloud Bigtable is ideal for time-series data due to its high throughput and low latency.

33. Your application requires a globally distributed relational database with strong consistency. Which GCP service should you choose?

A. Cloud SQL
B. Cloud Spanner
C. BigQuery
D. Firestore

Answer: B. Cloud Spanner
Explanation: Cloud Spanner offers global distribution with strong consistency and high availability, making it suitable for mission-critical applications.

34. Which GCP service allows you to run SQL queries on structured data using a serverless architecture?

A. Cloud SQL
B. BigQuery
C. Cloud Spanner
D. Firestore

Answer: B. BigQuery
Explanation: BigQuery is a serverless, highly scalable, and cost-effective multi-cloud data warehouse designed for business agility.

35. You need to implement a caching layer to reduce latency for read-heavy workloads. Which GCP service should you use?

A. Cloud SQL
B. Cloud Spanner
C. Memorystore
D. BigQuery

Answer: C. Memorystore
Explanation: Memorystore provides fully managed in-memory data stores for Redis and Memcached, ideal for caching and reducing latency.

36. Which GCP service provides a NoSQL document database with real-time synchronization?

A. Cloud SQL
B. Firestore
C. BigQuery
D. Cloud Spanner

Answer: B. Firestore
Explanation: Firestore is a NoSQL document database that supports real-time data synchronization, making it suitable for mobile and web applications.

37. You want to schedule regular exports of your Cloud SQL database to Cloud Storage. Which GCP service should you use?

A. Cloud Scheduler
B. Cloud Functions
C. Dataflow
D. Pub/Sub

Answer: A. Cloud Scheduler
Explanation: Cloud Scheduler allows you to schedule virtually any job, including batch, big data jobs, and cloud infrastructure operations.

38. Which GCP service is best suited for analyzing streaming data in real-time?

A. BigQuery
B. Dataflow
C. Cloud SQL
D. Firestore

Answer: B. Dataflow
Explanation: Dataflow is a fully managed service for stream and batch data processing, ideal for real-time analytics.

39. You need to replicate Cloud SQL data to BigQuery for analytics with minimal latency. What should you use?

A. BigQuery Data Transfer Service
B. Dataflow
C. Cloud SQL Replication
D. Cloud Composer

Answer: B. Dataflow
Explanation: Dataflow enables near real-time data ingestion, transformation, and loading from Cloud SQL to BigQuery using stream processing.

40. What is the best way to ensure high availability for Cloud SQL in a production environment?

A. Enable read replicas
B. Use multi-AZ configuration
C. Backup daily
D. Increase CPU and RAM

Answer: B. Use multi-AZ configuration
Explanation: Cloud SQL’s high availability configuration ensures automated failover by replicating data across multiple zones.

41. Which storage system is optimized for storing large volumes of binary and object data?

A. Cloud SQL
B. Cloud Spanner
C. Cloud Bigtable
D. Cloud Storage

Answer: D. Cloud Storage
Explanation: Cloud Storage is designed to store unstructured data such as images, videos, and backups efficiently.

42. Your team wants to reduce operational overhead for schema changes in a relational database. Which option is best?

A. Use Firestore
B. Use BigQuery
C. Use Cloud Spanner
D. Use Cloud SQL with manual migrations

Answer: C. Use Cloud Spanner
Explanation: Cloud Spanner supports online schema changes without downtime, reducing operational overhead.

43. A GCP customer is concerned about compliance and needs customer-managed encryption keys. Which database services support CMEK?

A. Cloud SQL and BigQuery
B. Cloud Spanner and Firestore
C. All the above
D. Only Cloud SQL

Answer: C. All the above
Explanation: Cloud SQL, Cloud Spanner, BigQuery, and Firestore support CMEK for customers needing full control of encryption keys.

44. What’s the most appropriate method to enforce encryption in transit for Cloud SQL?

A. Configure SSL certificates
B. Use a service account
C. Enable VPC peering
D. Restrict public IP access

Answer: A. Configure SSL certificates
Explanation: Enabling SSL ensures encrypted connections between clients and Cloud SQL databases.

45. Which of the following best describes BigQuery’s pricing model?

A. Flat monthly fee
B. Per-second usage
C. On-demand and flat-rate
D. Reserved instance billing

Answer: C. On-demand and flat-rate
Explanation: BigQuery charges per query (on-demand) or via flat-rate monthly pricing for predictable workloads.

46. What does Bigtable require to be efficient for time-series data?

A. Structured schema
B. Single-node configuration
C. Proper row key design
D. Strong SQL joins

Answer: C. Proper row key design
Explanation: Bigtable’s performance depends heavily on row key design to ensure balanced read/write distribution.

47. You need to manage access to Cloud SQL at a granular level. What is the best method?

A. Use SQL GRANT statements only
B. IAM Roles with Identity-Aware Proxy
C. Create separate instances per user
D. Enable API access logs

Answer: B. IAM Roles with Identity-Aware Proxy
Explanation: IAM roles provide fine-grained access control, and Identity-Aware Proxy adds additional security layers.

48. Your Cloud SQL instance is reaching storage limits frequently. What should you do?

A. Restart the instance
B. Scale CPU
C. Enable automatic storage increase
D. Export and delete old records

Answer: C. Enable automatic storage increase
Explanation: This setting allows Cloud SQL to automatically add more disk space as needed without downtime.

49. For multi-tenant SaaS applications requiring isolation, which strategy is best in Cloud SQL?

A. Use one shared database
B. Use separate schemas per tenant
C. Use separate instances per tenant
D. Use BigQuery for each tenant

Answer: B. Use separate schemas per tenant
Explanation: Separate schemas provide isolation with manageable overhead compared to full instance separation.

50. What is the best choice for a low-latency, key-value store that can scale horizontally?

A. Cloud SQL
B. Cloud Spanner
C. Cloud Bigtable
D. Memorystore

Answer: C. Cloud Bigtable
Explanation: Bigtable is ideal for massive scale and low-latency key-value storage use cases.

51. What is a key benefit of using Cloud Composer for database workflows?

A. Reduces query execution time
B. Automates and orchestrates ETL tasks
C. Adds extra memory to queries
D. Backs up databases automatically

Answer: B. Automates and orchestrates ETL tasks
Explanation: Cloud Composer is a managed Apache Airflow service for orchestrating complex workflows, including database operations.

52. Which service supports petabyte-scale analytics over structured data?

A. Firestore
B. Cloud Spanner
C. Cloud SQL
D. BigQuery

Answer: D. BigQuery
Explanation: BigQuery is a serverless data warehouse designed for analyzing large-scale structured data efficiently.

53. Which Cloud SQL engine supports automatic failover with minimal configuration?

A. SQL Server
B. MySQL
C. PostgreSQL
D. Both B and C

Answer: D. Both B and C
Explanation: MySQL and PostgreSQL support Cloud SQL’s high availability configuration with automated failover.

54. To reduce cost while using BigQuery for periodic reports, what is recommended?

A. Use on-demand pricing
B. Use flat-rate pricing
C. Use scheduled queries and partitioned tables
D. Export data to CSV

Answer: C. Use scheduled queries and partitioned tables
Explanation: Partitioning tables reduces the amount of data scanned, which lowers cost. Scheduled queries automate reports.

55. Which of these features is unique to Cloud Spanner among GCP database services?

A. Global distribution with strong consistency
B. Schema-less data
C. Columnar storage
D. Key-value design

Answer: A. Global distribution with strong consistency
Explanation: Cloud Spanner is the only GCP service offering horizontal scalability with strong global consistency.

56. You need to transform and clean data before inserting into a database. What tool should you use?

A. Pub/Sub
B. Dataflow
C. Cloud Functions
D. Cloud SQL

Answer: B. Dataflow
Explanation: Dataflow allows for transformation and cleaning of data in stream and batch pipelines before loading it into databases.

57. Which BigQuery feature allows secure data sharing across organizations?

A. Data masking
B. Authorized views
C. Row-level security
D. Access logs

Answer: B. Authorized views
Explanation: Authorized views let you share query results securely without exposing the underlying data.

58. What does horizontal scaling in Cloud Spanner involve?

A. Adding more CPU to an instance
B. Adding more disk space
C. Increasing number of nodes
D. Upgrading the database engine

Answer: C. Increasing number of nodes
Explanation: Horizontal scaling in Spanner means adding more nodes to increase compute and storage capacity.

59. Which service would you use to automate Cloud SQL backups and manage lifecycle?

A. Cloud Scheduler
B. Cloud Functions
C. Cloud Composer
D. All of the above

Answer: D. All of the above
Explanation: Cloud Scheduler can trigger jobs, Cloud Functions can run scripts, and Composer can orchestrate multi-step workflows.

60. What should you implement to ensure zero data loss in Cloud Spanner?

A. Regional configuration
B. Multi-region configuration
C. Daily backups
D. Identity-Aware Proxy

Answer: B. Multi-region configuration
Explanation: Multi-region Spanner instances provide synchronous replication and strong consistency, minimizing risk of data loss.