50 Cloud Database Engineer Practice Questions: Question Bank 2025

An online retail application uses Cloud SQL for PostgreSQL. The database must remain available during a zonal outage, and the application requires a single writable primary endpoint. What should you implement?

You need to provision a Cloud SQL instance that is only accessible from applications running on GKE in the same project and VPC. Public internet access must be disabled. What is the recommended approach?

A team needs to migrate a MySQL database from on-premises to Cloud SQL with minimal downtime. They can tolerate a brief read-only window for cutover but want ongoing replication during the migration. Which approach is best?

You need to store transactional data that requires horizontal scalability and strong consistency for reads and writes. The system should handle high write throughput without manual sharding. Which database service should you choose?

Your Cloud SQL for PostgreSQL instance experiences periodic CPU spikes and increased query latency. You suspect a small set of queries is responsible. What is the most appropriate first step to identify the problematic queries?

A Cloud Spanner database must enforce that application services can only read specific tables and can only write through specific stored logic. You want least-privilege access and centralized authorization. What should you do?

You are migrating a PostgreSQL database to Cloud SQL. You need to validate schema compatibility and estimate potential migration blockers before starting the migration. Which is the best approach?

A team is provisioning Cloud SQL instances via Terraform. They want to ensure production instances have automated backups enabled, point-in-time recovery configured (where supported), and deletion protection turned on. What is the best way to enforce these requirements consistently?

A globally distributed application requires a relational database with strong consistency. Most reads are served locally in multiple regions, but writes are relatively low and must be consistent. You choose Cloud Spanner with multi-region configuration. You notice increased write latency after moving to a multi-region setup. Which design change is most likely to reduce write latency while preserving strong consistency?

You operate Cloud SQL for PostgreSQL with a private IP. An application in another project (same organization) must connect securely without exposing the database publicly. The projects use separate VPCs. You want the simplest, scalable connectivity pattern with minimal operational overhead. What should you implement?

Your team is deploying a Cloud SQL for PostgreSQL instance for a production workload. The business requires high availability across zones and minimal downtime during a zonal failure. What should you do?

You need to quickly grant an application running on GKE access to a Cloud SQL instance without using long-lived database passwords in Kubernetes Secrets. What is the recommended approach?

A team wants to migrate an on-premises PostgreSQL database to Cloud SQL for PostgreSQL with minimal downtime. They can accept a short cutover window but want continuous replication during the migration. Which approach best fits?

You operate a Cloud Spanner database that experiences periodic bursts of traffic causing elevated p99 latency. You want to keep costs controlled but avoid latency spikes during predictable daily peaks. What should you do?

A Cloud SQL for MySQL instance is showing high CPU usage. Query insights indicates a single query is frequently executed and scans a large table. You want to improve performance with minimal risk. What should you do first?

You need to provision a Cloud SQL instance for a workload with strict private connectivity requirements: no public IP, access only from resources in the same VPC, and centralized DNS naming. What is the best configuration?

You are migrating a multi-terabyte on-premises MySQL database to Cloud SQL for MySQL. The initial load is too slow using a logical dump. You want to reduce migration time while maintaining correctness. What should you do?

A company needs a globally distributed transactional database with strong consistency and five 9s availability for a mission-critical system. They also want to minimize operational overhead and avoid manual sharding. Which database service best meets these requirements?

After enabling customer-managed encryption keys (CMEK) for a Cloud SQL instance, the instance fails to start following a maintenance event. Logs indicate permission errors accessing the key. What is the most likely cause and fix?

You are designing a multi-tenant SaaS on Cloud Spanner. Tenants require strict data isolation, and you need the ability to quickly revoke a tenant’s access without redeploying the application. You want to minimize operational overhead as the number of tenants grows. What should you do?

You manage a Cloud SQL for PostgreSQL instance used by an internal app. You want developers to access the database from their laptops without exposing the instance to the public internet. The developers use various networks and do not have a corporate VPN. What should you implement?

A team is migrating to Cloud Spanner and needs to ensure that each write is strongly consistent and immediately visible to subsequent reads globally. Which read option should they use after a write in the same transaction context?

You need to quickly create a development Cloud SQL instance with the same schema and a recent copy of production data for troubleshooting. Production has automated backups enabled. What is the recommended approach?

An on-premises PostgreSQL database must be migrated to Cloud SQL for PostgreSQL with minimal downtime. You can open network connectivity from on-premises to Google Cloud, and you need continuous replication until cutover. Which approach best fits?

A Cloud Spanner application is experiencing periodic high latency on reads. Monitoring shows CPU is low, but there are spikes in storage reads and network. The schema includes several wide secondary indexes that are rarely used. What is the best next step to reduce read amplification and latency?

You are designing a multi-tenant SaaS on Cloud SQL for MySQL. Tenants must be isolated so that a compromise of one tenant’s app credentials cannot access other tenants’ data. Operational overhead should be low. Which design is the best fit?

Your Cloud SQL for PostgreSQL instance is used by a batch job that opens thousands of short-lived connections, causing frequent 'too many connections' errors and CPU spikes. You want to reduce connection overhead without changing the application significantly. What should you do?

A global e-commerce platform runs on Cloud Spanner. A new reporting feature requires scanning large ranges of historical orders and is impacting OLTP latency. You need to isolate analytical scans while keeping data in Spanner and maintaining strong consistency for transactional workloads. What should you implement?

You are migrating a large on-premises MySQL database to Cloud SQL with Database Migration Service (DMS). The initial load completes, but the replication phase shows growing lag. On-premises has limited outbound bandwidth, and you cannot increase it. What is the best way to reduce lag while keeping near-zero downtime goals?

A security review requires that Cloud SQL data be protected so Google personnel cannot access customer data without customer-controlled approval. You need encryption with customer-controlled keys and the ability to revoke access. What should you use?

A team needs a PostgreSQL database on Google Cloud that remains available even if a zonal outage occurs. They want automatic failover with minimal operational overhead. What should they deploy?

You are provisioning a new Cloud Spanner instance for a latency-sensitive application used globally. The application is read-heavy and requires strong consistency for some reads but can tolerate eventual consistency for most reads. What is the best approach?

An operations team needs to ensure all Cloud SQL instances are created with deletion protection enabled and a mandatory set of database flags. They want this enforced automatically at provisioning time across projects. What should they use?

A developer accidentally deleted a table in a Cloud SQL for MySQL database. You need to restore the database to its state from 10 minutes ago with minimal data loss. What should you use (assuming it was configured)?

You are migrating an on-premises PostgreSQL database to Cloud SQL for PostgreSQL with minimal downtime. The source database has ongoing writes and you need a controlled cutover. What is the recommended migration approach?

A team is moving an analytics workload from a self-managed Hadoop cluster to Google Cloud. They want to run SQL over large append-only datasets and avoid managing database servers. Which service is the best fit?

Your Cloud SQL for PostgreSQL instance shows high CPU and many queries with sequential scans on a large table. You need to identify the most expensive queries and confirm whether indexes would help. What should you do first?

A security team requires that applications connect to Cloud SQL without storing long-lived database passwords. They want centralized IAM control and short-lived credentials. What should you implement?

You are designing a globally distributed transactional system that requires external consistency, high availability across regions, and horizontal scaling without manual sharding. Which database should you choose?

You need to move a large amount of data (hundreds of TB) from an on-premises database export stored on local disks to Cloud Storage to start a BigQuery load. The network link is slow and unreliable, and the transfer must be predictable. What should you use?

You manage a Cloud SQL for PostgreSQL instance. Developers need to connect from Cloud Run without managing passwords, and credentials must be rotated automatically. What is the recommended approach?

A team needs a MySQL-compatible database for a new application and wants automatic storage scaling and the ability to create read replicas with minimal administration. Which Google Cloud database service best fits?

You plan to migrate a PostgreSQL database to Cloud SQL. During assessment you identify several large tables without primary keys and frequent UPDATE/DELETE operations. What should you do first to reduce migration risk and replication issues?

Your global application needs strongly consistent reads and writes across multiple regions with horizontal scaling and high availability. You want minimal operational overhead and automatic sharding. Which database should you choose?

A Cloud SQL for PostgreSQL instance experiences periodic CPU spikes and increased latency during business hours. Query Insights shows frequent full table scans on a large table. What is the best next step?

You are provisioning Cloud SQL for PostgreSQL for a regulated workload. The security team requires all database traffic to stay within Google’s network and to avoid exposing the instance to the public internet. What should you do?

A company uses Bigtable for time-series data. They notice hotspots and uneven node CPU utilization because most writes target a small range of row keys. What is the recommended design change?

You are migrating an on-prem PostgreSQL database to AlloyDB for PostgreSQL with minimal downtime. The business requires continuous replication until cutover and validation that the target is in sync. Which approach is most appropriate?

You need to provide application developers a safe way to test schema changes against production-like data in Cloud SQL while minimizing risk of exfiltration of sensitive fields (PII). What is the best solution?

A mission-critical Cloud Spanner database needs protection from accidental deletes and must support point-in-time recovery for operational mistakes. The organization also needs a geographically isolated copy for disaster recovery drills. Which combination meets these requirements with least operational overhead?