PCD Practice Test 45 — 15 Questions

Question 1

During an Oracle to PostgreSQL migration using Ora2Pg, a developer notices that PL/SQL packages are not being converted correctly. What is the recommended strategy to handle Oracle packages in PostgreSQL?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Recreate each procedure/function as a separate function in a dedicated schema, and use temporary tables for package variables.. PostgreSQL does not have a direct equivalent of Oracle packages. The recommended approach is to convert package procedures and functions to individual functions in a schema, and package variables to session-level variables or temporary tables. Ora2Pg can attempt conversion but often requires manual adjustments.

Answer

Use pglogical to replicate Oracle data to PostgreSQL and rewrite application code to call PostgreSQL functions directly.

Answer

Keep the Oracle database as a read replica and use Oracle Foreign Data Wrapper for PostgreSQL.

Answer

Use PostgreSQL's CREATE PACKAGE extension (available in some forks) to maintain package structure.

Question 2

An application running on GKE needs to access a Cloud SQL instance. The team wants to avoid using Cloud SQL Auth Proxy to reduce complexity. What is the most secure alternative?

Accepted Answer

Use Private Service Connect to connect privately.. Private Service Connect (PSC) allows your GKE cluster to connect to Cloud SQL privately using internal IPs within the same VPC, without exposing traffic to the public internet or requiring the Cloud SQL Auth Proxy. PSC creates a private endpoint that routes traffic through Google's internal network, providing secure, low-latency connectivity while reducing operational overhead.

Answer

Whitelist the GKE node external IPs in Cloud SQL authorized networks.

Answer

Use a Cloud SQL read replica with a public IP.

Answer

Configure Cloud SQL to allow all traffic from the VPC.

Question 3

You are setting up Cloud Build to automatically deploy a container to Cloud Run when code is pushed to the main branch of a GitHub repository. What is the minimal configuration required?

Accepted Answer

Create a Cloud Build trigger connected to GitHub, and include a cloudbuild.yaml with steps to build and deploy.. Cloud Build triggers can be configured to automatically execute a build pipeline when code is pushed to a GitHub repository. The minimal configuration requires a trigger connected to GitHub and a cloudbuild.yaml file that defines the steps to build the container image and deploy it to Cloud Run using the `gcloud run deploy` command or the `cloudrun` builder. This setup provides a fully automated CI/CD pipeline without additional services.

Answer

Set up GitHub Actions to push images to Container Registry and then use Cloud Run.

Answer

Create a Cloud Build trigger without a build config file, using the inline builder.

Answer

Use Artifact Registry to store images and then manually trigger deployment.

Question 4

Your team manages a service that receives thousands of requests per second. They have set up Cloud Monitoring alerting based on the 99th percentile latency. Recently, they received an alert warning that latency exceeded 1 second, but after investigating, they found it was a false alarm caused by a single very slow request. How can they improve their alert to reduce false positives?

Accepted Answer

Use a different latency metric like median or 95th percentile.. Using a different latency metric like the 95th percentile reduces sensitivity to outliers. The 99th percentile captures the slowest 1% of requests, so a single very slow request can trigger an alert. The 95th percentile ignores the top 5% of outliers, making it more robust against isolated slow requests while still monitoring tail latency effectively.

Answer

Set the alert to fire only if the condition persists for a longer duration.

Answer

Use a log-based metric instead of latency.

Answer

Increase the alerting threshold to 2 seconds.

Question 5

A company is migrating from on-premises SQL Server to Cloud SQL SQL Server using Database Migration Service (DMS). During the continuous migration phase, they notice that the replication lag is increasing. What is the most likely cause?

Accepted Answer

Large transactions on the source database are causing CDC to fall behind.. Database Migration Service (DMS) uses Change Data Capture (CDC) to replicate ongoing changes from the source SQL Server to the target Cloud SQL instance. Large transactions on the source database generate a high volume of log records that the CDC reader must process sequentially. If the transaction volume exceeds the throughput capacity of the DMS replication slot, the lag between the source and target increases, causing the replication lag to grow.

Answer

The DMS migration job is not using a source read replica.

Answer

The target Cloud SQL instance is not using Premium tier.

Answer

The source database has a low transaction log retention period.

Question 6

An engineer needs to create a Cloud SQL instance with SSD storage. Which storage type should they select for best performance?

Accepted Answer

SSD (solid-state drive). SSD (solid-state drive) is the recommended storage type for Cloud SQL instances when best performance is required. SSD provides lower latency and higher IOPS compared to HDD, making it suitable for transactional workloads and real-time applications. Cloud SQL supports both SSD and HDD, but SSD is the default and optimal choice for production databases.

Answer

HDD (hard disk drive)

Answer

Local SSD

Answer

Persistent disk standard

Question 7

A team is deploying a containerized application to Google Kubernetes Engine using a Deployment and a Service of type LoadBalancer. The application is a web server that should be accessible on port 80. After deployment, the external IP is assigned, but when they try to access http://<EXTERNAL_IP>:80, they get a connection timeout. The pods are running, and the logs show the web server is listening on port 8080. The team has verified that the cluster firewall rules allow traffic on port 80. They have also confirmed that the pods are healthy and no network policies are in place. What is the most likely cause?

Accepted Answer

The Deployment's containerPort is set to 8080, but the Service's port is set to 80 and targetPort is not specified.. If the Service's targetPort is not specified, it defaults to the same value as the port (80). However, the container is listening on port 8080, so traffic forwarded to port 80 on the pod results in a connection timeout. Option A is incorrect because the team verified that no network policies are in place, and firewall rules allow traffic on port 80. Option C is incorrect because externalTrafficPolicy: Local affects client IP preservation, not basic connectivity. Option D is incorrect because the team did not explicitly set targetPort; it defaults to 80. If it were set to 80, that would also cause the timeout, but the issue is the default behavior.

Answer

The cluster has a network policy that blocks incoming traffic.

Answer

The Service is missing the externalTrafficPolicy: Local setting.

Answer

The Service's targetPort is set to 80 instead of 8080.

Question 8

A company runs a stateful application on Compute Engine instances with local SSDs. They need to perform maintenance that requires stopping the instances. What is the best approach to ensure data durability and minimal downtime?

Accepted Answer

Migrate data to persistent disks and configure the application to use persistent disks. Local SSDs provide ephemeral storage that is tied to the lifecycle of the Compute Engine instance. When an instance is stopped or terminated, data on local SSDs is permanently lost. To ensure data durability during maintenance that requires stopping the instance, the application must use persistent disks, which are durable network-attached storage that persists independently of the instance. Option D is correct because migrating the application to persistent disks ensures data survives the stop and allows the instance to be restarted with the same data, minimizing downtime.

Answer

Create a snapshot of the local SSD before stopping the instance

Answer

Use instance groups with autohealing to automatically recreate instances

Answer

Enable live migration on the instance

Question 9

Your Cloud Run service is experiencing 5xx errors. You have enabled Cloud Logging and Cloud Error Reporting. How can you quickly identify the most common error type?

Accepted Answer

Open Cloud Error Reporting to see grouped error counts.. Cloud Error Reporting automatically groups similar errors (e.g., same stack trace or error message) and shows a count for each group, making it the fastest way to identify the most common 5xx error type without manual log inspection. It is purpose-built for this exact use case, aggregating errors from Cloud Logging and presenting them in a dashboard sorted by frequency.

Answer

Use Cloud Trace to analyze the traces of failing requests.

Answer

View the logs in Cloud Logging and manually count error messages.

Answer

Create a Cloud Monitoring alert on 5xx response codes.

Question 10

A company is deploying a new web application on Google Cloud and needs a managed relational database with PostgreSQL compatibility. The database must support automatic failover within 60 seconds in case of a zone outage. Which database deployment option should they choose?

Accepted Answer

Cloud SQL regional HA configuration. Cloud SQL with regional HA configuration provisions a primary and a standby instance in different zones within the same region, using synchronous replication to enable automatic failover in under 60 seconds. This meets the requirement for high availability within a single region.

Answer

Cloud SQL single zone with automatic storage increase

Answer

Spanner multi-region configuration

Answer

AlloyDB with a read pool of 2 instances

Question 11

A company is deploying a globally distributed user authentication service using Cloud Spanner. They need strong consistency for all reads and writes. Which two features should they use? (Choose two.)

Accepted Answer

Use strong reads (read timestamp = now). Strong reads (read timestamp = now) and mutations API with commit timestamp are used for strong consistency. Stale reads and bounded staleness are for weaker consistency. Read-write transactions also provide strong consistency, but the question asks for features. The two correct are: strong reads and using commit timestamps for writes.

Answer

Enable read-your-writes consistency

Answer

Use stale reads to reduce latency

Answer

Use bounded staleness reads

Question 12

A team wants to monitor CPU utilization on their Compute Engine instances. They need an alert that sends a notification when the average CPU utilization across all instances in a project exceeds 80% for more than 5 minutes. Which alerting configuration should they use?

Accepted Answer

Create an alert policy with a metric threshold condition for compute.googleapis.com/instance/cpu/utilization, aggregated across all instances with alignment period 1 min and duration 5 min. Cloud Monitoring alert policies allow you to define a metric threshold condition using the `compute.googleapis.com/instance/cpu/utilization` metric, aggregate it across all instances in the project, and set an alignment period of 1 minute with a duration of 5 minutes. This configuration ensures the alert fires only when the average CPU utilization exceeds 80% for a sustained period of 5 minutes, meeting the exact requirement.

Answer

Use Cloud Scheduler to periodically check CPU and trigger notification

Answer

Create a log-based alert using metrics from Cloud Logging

Answer

Use an uptime check to monitor CPU utilization

Question 13

A company is planning to migrate from MySQL to Cloud SQL for MySQL. They want to ensure the migrated database meets performance and security requirements. Which TWO configurations should they apply to Cloud SQL?

Accepted Answer

Configure the Cloud SQL instance to require SSL/TLS for all connections.. Enabling point-in-time recovery is important for data protection. Enforcing TLS ensures encrypted connections. These are common security and operational requirements.

Answer

Migrate all tables to MyISAM storage engine for better performance.

Answer

Set the database flag 'skip_grant_tables' for faster migration.

Answer

Disable the query cache to improve concurrency.

Question 14

An engineer needs to secure a Cloud SQL for MySQL instance that contains sensitive data. They want to ensure that only specific Compute Engine VMs in the same VPC can connect, and that all connections are encrypted. Which THREE steps should they take? (Choose three.)

Accepted Answer

Enable IAM database authentication.. Private IP restricts access to the VPC. SSL enforcement ensures encryption. IAM database authentication adds an extra layer of security by allowing IAM-based login. Public IP would expose the instance. Authorized networks are for public IP access, which is not desired. Cloud SQL Auth Proxy can be used but not necessary if using private IP with SSL; the proxy adds another layer but is not required for this basic encryption and access control.

Answer

Assign a public IP address to the instance.

Answer

Add the VMs' IP addresses to the authorized networks.

Question 15

To monitor Cloud SQL query performance, which metric should an engineer examine to see the rate of queries being executed?

Accepted Answer

database/queries. The metric 'database/queries' tracks the number of queries executed per second. CPU/memory/disk utilization metrics are resource-oriented, not query-oriented.

Answer

database/disk/bytes_used

Answer

database/memory/utilization

Answer

database/cpu/utilization