PCD Practice Test 20 — 15 Questions

Question 1

Refer to the exhibit. You are analyzing application logs and notice that some logs contain a 'trace' field. What does this field enable?

Accepted Answer

It links the log entry to a specific Cloud Trace trace for end-to-end latency analysis. The 'trace' field in a log entry contains the trace ID and span ID that link the log to a specific Cloud Trace trace. This enables end-to-end latency analysis by correlating log entries with the distributed trace that generated them, allowing you to see the full request path across services.

Answer

It is used by Cloud Monitoring to correlate logs with metrics

Answer

It is used to export the log to Cloud Trace

Answer

It indicates that the log was generated by the Cloud Trace agent

Question 2

A company wants to replicate data from an on-premises Oracle database to BigQuery for analytics. They need serverless, near-real-time CDC with minimal operational overhead. Which service should they use?

Accepted Answer

Datastream. Datastream is a serverless, fully managed change data capture (CDC) and replication service that streams data from Oracle (and other sources) into BigQuery with near-real-time latency. It uses log-based CDC (Oracle Redo Logs) to capture changes without impacting source performance, and it handles schema mapping and data transformation automatically, minimizing operational overhead.

Answer

Cloud Data Fusion with Oracle plugin

Answer

Cloud Composer with scheduled jobs

Answer

Dataflow with a Java transformation

Question 3

Which THREE of the following are valid reasons to use Cloud Deploy instead of manually applying kubectl commands in a CI/CD pipeline?

Accepted Answer

Cloud Deploy maintains a deployment history for auditing.. Option B is correct because Cloud Deploy records each rollout and release in a delivery pipeline, giving a persistent, auditable deployment history that manual kubectl commands do not provide. Option D is correct because Cloud Deploy can automatically roll back a failed rollout to the last known-good release, whereas manual kubectl apply offers no built-in rollback automation. Option E is correct because Cloud Deploy natively supports progressive delivery strategies such as canary and blue-green through its rollout configuration, which would otherwise require custom scripting with kubectl. Option A is not correct because Cloud Deploy deploys already-built container images to GKE, Cloud Run, or Anthos; it does not build or containerize applications (that is Cloud Build or Buildpacks). Option C is not correct because IAM roles on Kubernetes clusters are enforced by GKE/IAM itself, not by Cloud Deploy as a deployment mechanism.

Answer

Cloud Deploy automatically containerizes applications.

Answer

Cloud Deploy enforces IAM roles on Kubernetes clusters.

Question 4

During a deployment to App Engine flexible environment, the new version fails to start and the logs show 'Container failed to start: context deadline exceeded'. The previous version remains serving traffic. What is the most likely cause?

Accepted Answer

The container startup time exceeds the 10-minute timeout.. The error 'context deadline exceeded' in App Engine flexible environment indicates that the container did not start within the allowed startup timeout. The default timeout for container startup in App Engine flexible is 10 minutes, and if the application takes longer (e.g., due to slow initialization, large dependency downloads, or database migrations), the platform kills the container and logs this error. The previous version continues serving because the new version failed to become healthy.

Answer

The health check is misconfigured, causing the instance to be considered unhealthy.

Answer

The app requires an environment variable that is not set.

Answer

The Dockerfile has a syntax error that prevents the container from building.

Question 5

A team is designing a cloud-native application that must be highly available and resilient to zone failures. Which three practices should they follow? (Choose three.)

Accepted Answer

Deploy resources across multiple zones.. Option B is correct because spreading resources across multiple zones ensures that a failure of any single zone does not take down the entire application, which is the foundation of zone-failure resilience. Option D is correct because regional persistent disks synchronously replicate data across two zones in the same region, so a zone outage does not cause data loss or unavailability. Option E is correct because health checks detect unhealthy instances and autohealing automatically recreates them, maintaining capacity and availability without manual intervention. Option A is not sufficient on its own: a single load balancer with multiple backends can still have all backends in one zone, so it does not inherently provide zone-failure resilience. Option C is incorrect because zonal managed instance groups are confined to a single zone, and running at 100% target utilization leaves no headroom to absorb failures or traffic spikes.

Answer

Use a single Load Balancer with multiple backends.

Answer

Use zonal managed instance groups with 100% target utilization.

Question 6

An organization is migrating a large Oracle database to Cloud SQL for PostgreSQL. They need to handle Oracle's SEQUENCE objects, which are used for primary key generation. Which THREE approaches are valid for this migration?

Accepted Answer

Replace Oracle sequences with PostgreSQL SERIAL columns.. Option B is correct because PostgreSQL SERIAL columns are implemented as an integer column with an attached sequence and an automatic DEFAULT nextval(), which directly reproduces Oracle's sequence-driven primary key generation with minimal application changes. Option C is correct because PostgreSQL's IDENTITY columns (GENERATED ALWAYS AS IDENTITY or GENERATED BY DEFAULT AS IDENTITY) are the SQL-standard replacement for Oracle sequences, providing the same auto-incrementing behavior with proper ownership tied to the column. Option D is correct because you can explicitly create a PostgreSQL sequence with CREATE SEQUENCE and reference nextval('seq_name') in INSERT statements, which is the closest one-to-one translation of Oracle's sequence.nextval usage. Option A is not appropriate because replacing sequences with application-generated UUIDs changes the data type, key semantics, and application logic rather than migrating the existing sequence behavior. Option E is not valid because PostgreSQL has no built-in compatibility layer that lets Oracle sequence objects be used directly; sequences must be recreated natively as PostgreSQL sequences, SERIAL, or IDENTITY columns.

Answer

Remove all sequences and use UUIDs generated by the application.

Answer

Use Oracle sequences directly in PostgreSQL via a compatibility layer.

Question 7

An organization is migrating an on-premises PostgreSQL database to Cloud SQL. They want to minimize downtime during the cutover. Which Google Cloud service should they use to perform an online migration with near-zero downtime?

Accepted Answer

Database Migration Service. Database Migration Service (DMS) is Google Cloud's managed service for migrating MySQL, PostgreSQL, and SQL Server databases to Cloud SQL with continuous replication, enabling a short cutover with near-zero downtime. It handles initial snapshot plus change data capture so the source stays live until the final promotion. This directly matches the online migration requirement.

Answer

BigQuery Data Transfer Service

Answer

Cloud Dataflow

Answer

Transfer Appliance

Question 8

A company is deploying a containerized application on Google Kubernetes Engine (GKE). The deployment uses a Service of type LoadBalancer. After creating the Service, the external IP remains pending for several minutes. The team has verified that the cluster has sufficient node capacity and that the pod is running. What is the most likely cause?

Accepted Answer

The project's quota for external IP addresses has been exhausted.. When a Service of type LoadBalancer is created in GKE, it provisions an external IP address from the project's quota. If the quota for external IP addresses is exhausted, the IP assignment remains pending until additional quota is requested or released. The cluster having sufficient node capacity and the pod running confirms that the issue is not resource-related but rather a cloud-level quota limitation.

Answer

The Service is using an incorrect port mapping.

Answer

The pod's readiness probe is failing.

Answer

The cluster is using a regional cluster type.

Question 9

You need a fully managed, relational OLTP database that is PostgreSQL-compatible and can run analytical queries on the same data without extract-transform-load (ETL). Which Google Cloud database should you use?

Accepted Answer

AlloyDB. AlloyDB is a fully managed, PostgreSQL-compatible database service designed for both transactional (OLTP) and analytical workloads on the same data without requiring ETL. It achieves this through its AlloyDB Columnar Engine, which automatically accelerates analytical queries by storing data in a columnar format while maintaining full PostgreSQL compatibility for OLTP operations.

Answer

Cloud Bigtable

Answer

Cloud SQL for PostgreSQL

Answer

Cloud Spanner

Question 10

An organization is migrating from Amazon Redshift to BigQuery. They have large datasets stored in Amazon S3. What is the most efficient method to migrate the data?

Accepted Answer

Export Redshift data to S3, copy to Cloud Storage using Storage Transfer Service, then load into BigQuery.. The most efficient migration path is to export Redshift data to Amazon S3 (using UNLOAD), transfer it to Cloud Storage via Storage Transfer Service, and then load it into BigQuery using native load jobs. This uses each platform's optimized bulk-transfer mechanisms and avoids unnecessary intermediate databases or federated queries that are slow and not designed for large-scale migration.

Answer

Create a VPN between AWS and GCP and use federated query in BigQuery to read from Redshift directly.

Answer

Use Cloud Data Fusion to read from Redshift directly and write to BigQuery.

Answer

Use AWS Database Migration Service (DMS) to replicate data to Cloud SQL and then use BigQuery federated query.

Question 11

A company is migrating a PostgreSQL database to AlloyDB using Database Migration Service. They need to ensure the migration has minimal downtime and can be tested before cutover. Which THREE steps should they include in their migration plan?

Accepted Answer

Create a migration job with 'Full dump + CDC' to enable continuous replication.. Option A is correct because a 'Full dump + CDC' migration job in Database Migration Service performs an initial full load followed by continuous change data capture, which keeps the target AlloyDB instance in sync and enables minimal-downtime cutover. Option B is correct because DMS relies on logical replication (via logical decoding, e.g., the pglogical or native logical replication setup) on the source PostgreSQL database to stream ongoing changes; without it, CDC cannot capture inserts, updates, and deletes. Option D is correct because DMS requires a connection profile that stores the source PostgreSQL connection details (host, port, credentials) so the migration job can connect to and read from the source. Option C is not correct because promoting a replica is not part of the DMS migration workflow for testing; testing is done by running the migration job and validating the AlloyDB target, not by promoting a replica. Option E is not correct because a manual pg_dump/pg_restore bypasses DMS and does not provide continuous replication or the minimal-downtime cutover that the scenario requires.

Answer

Test the migration by promoting a replica in a non-production environment before final cutover.

Answer

Use pg_dump to take a manual backup and restore it to AlloyDB before setting up DMS.

Question 12

A company uses Cloud Spanner for a globally distributed application. They need to capture all changes from a Spanner table and send them to a BigQuery dataset for real-time analytics. Which THREE Google Cloud services or features should they use?

Accepted Answer

Dataflow. Spanner change streams (B) are the native Spanner feature that records data changes (inserts, updates, deletes) with commit timestamps, which is exactly what is needed to capture all changes from a Spanner table. Dataflow (A) provides the streaming pipeline that reads from those change streams and writes the records into BigQuery, handling the transformation and delivery in near real time. BigQuery (E) is the required destination, since the scenario explicitly states the changes must be sent to a BigQuery dataset for real-time analytics. Datastream (C) is a change data capture service for sources like MySQL, PostgreSQL, and Oracle, not Spanner, so it does not apply here. Cloud Functions (D) is an event-driven compute service that is not the standard mechanism for streaming Spanner change data into BigQuery.

Answer

Datastream

Answer

Cloud Functions

Question 13

A developer wants to ensure that error logs from their Java application are automatically captured and grouped in Cloud Error Reporting. What is the recommended approach?

Accepted Answer

Instrument the application with the Error Reporting client library. The Error Reporting client library directly integrates with the application to automatically capture and group error logs, sending them to Cloud Error Reporting without requiring additional infrastructure. This is the recommended approach as it provides structured error reporting with automatic grouping, stack trace analysis, and real-time notifications.

Answer

Configure a log sink to Error Reporting

Answer

Export logs to BigQuery and then import to Error Reporting

Answer

Use a custom log-based metric to count errors

Question 14

A company uses Cloud SQL for PostgreSQL and wants to set up a disaster recovery solution with cross-region backup copies. They also need point-in-time recovery (PITR) in the primary region. Which three steps should they take? (Choose three.)

Accepted Answer

Configure the backup retention period to your required PITR window.. Option C is correct because automated backups must be enabled on the Cloud SQL for PostgreSQL instance before PITR or cross-region backup copies can function; PITR relies on the transaction logs and backups that automated backups enable. Option A is correct because the backup retention period defines the window for which backups and logs are retained, and for PITR it must be set to cover the required recovery window (up to 7 days for PITR on Cloud SQL). Option D is correct because enabling cross-region backup copy in the Cloud SQL settings is the specific configuration that replicates automated backups to a secondary region for disaster recovery. Option B is not correct because promoting a read replica is a failover/migration action, not a step to configure cross-region backups or PITR. Option E is not correct because creating hourly on-demand backups is not the mechanism for PITR or cross-region copies, and on-demand backups do not provide the continuous log-based recovery that PITR requires.

Answer

Promote a read replica in the secondary region for migration.

Answer

Create an on-demand backup every hour for the last 7 days.

Question 15

An engineer is planning a database migration and needs to assess the source database's size, schema complexity, stored procedures, and dependencies. Which activity is this part of?

Accepted Answer

Database assessment. Database assessment is the discovery and analysis phase of a migration where the engineer inventories the source database's size, schema objects, stored procedures, dependencies, and complexity. This assessment produces the data needed to plan the migration strategy, choose conversion tools, and estimate effort. It precedes schema conversion and cutover planning, and is distinct from performance tuning, which optimizes an already-running system.

Answer

Cutover planning

Answer

Schema conversion

Answer

Performance tuning