Professional-Data-Engineer Google Professional Data Engineer Exam Free Practice Exam Questions (2025 Updated)

 By setting the topic retention policy to 30 days, you can ensure that any new subscriber can access the messages thatwere published to the topic within the last 30 days1. This feature allows youto replay previously acknowledged messages or initialize new subscribers with historical data2. You can configure the topic retention policy by using the Cloud Console, the gcloud command-line tool, or the Pub/Sub API1.

Option A is not efficient, as it requires creating a new topic and duplicating the data for each new subscriber, which would increase the storage costs and complexity. Option C is not effective, as it only affects the unacknowledged messages in a subscription, and does not allow new subscribersto access older data3. Option D is not feasible, as it depends on the source system’s ability and willingness to re-push the data, and it may cause data duplication or inconsistency. References:

1: Create a topic | Cloud Pub/Sub Documentation | Google Cloud

2: Replay and purge messages with seek | Cloud Pub/Sub Documentation | Google Cloud

3: When is a PubSub Subscription considered to be inactive?

Analytics Hub is a service that allows you to securely share and discover data assets across your organization and with external partners. You can use Analytics Hub to create and manage data assets, such as BigQuery datasets, views, and queries, and control who can access them. You can also browse and use data assets that others have shared with you. By using Analytics Hub, you can keep the costs of data sharing low and ensure that the data is current, as the data assets are not copied or moved, but rather referenced from their original sources.

To improve response times and reduce costs for frequent queries aggregating a large sales history fact table, materialized views are a highly effective solution. Here’s why option A is the best choice:

Materialized Views:

Materialized views store the results of a query physically and update them periodically, offering faster query responses for frequently accessed data.

They are designed to improve performance for repetitive and expensive aggregation queries by precomputing the results.

Efficiency and Cost Reduction:

By building materialized views at the day and month level, you significantly reduce the computation required for each query, leading to faster response times and lower query costs.

Materialized views also reduce the need for on-demand query execution, which can be costly when dealing with large datasets.

Minimized Maintenance:

Materialized views in BigQuery are managed automatically, with updates handled by the system, reducing the maintenance burden on your team.

Steps to Implement:

Identify Aggregation Queries:

Analyze the existing queries to identify common aggregation patterns at the day and month levels.

Create Materialized Views:

Create materialized views in BigQuery for the identified aggregation patterns. For example

CREATE MATERIALIZED VIEW project.dataset.sales_daily_summary AS

SELECT

DATE(transaction_time) AS day,

SUM(amount) AS total_sales

FROM

project.dataset.sales

GROUP BY

day;

CREATE MATERIALIZED VIEW project.dataset.sales_monthly_summary AS

SELECT

EXTRACT(YEAR FROM transaction_time) AS year,

EXTRACT(MONTH FROM transaction_time) AS month,

SUM(amount) AS total_sales

FROM

project.dataset.sales

GROUP BY

year, month;

Query Using Materialized Views:

Update existing queries to use the materialized views instead of directly querying the base table.

Reference Links:

BigQuery Materialized Views

Optimizing Query Performance

https://cloud.google.com/spanner/docs/instance-configurations#tradeoffs_regional_versus_multi-region_configurations

Identity and Access Management (IAM) is the recommended way to control access to Pub/Sub resources, such as topics and subscriptions. IAM allows you to grant roles and permissions to users and service accounts at the project level or the individual resource level. You can also use IAM conditions to specify additional attributes for granting or denying access, such as time, date, or origin. By using IAM conditions, you can ensure that only the resources in project A can access the data in the project A topic, regardless of the network configuration or the VPC Service Controls. You can also prevent project B and any future project from accessing the data in the project A topic by not granting them any roles or permissions on the topic.

Option A is not a good solution, as VPC Service Controls are designed to prevent data exfiltration from Google Cloud resources to the public internet, not to control access between Google Cloud projects. VPC Service Controls create a perimeter around the resources of one or more projects, and restrict the communication with resources outside the perimeter. However, VPC Service Controls do not apply to Pub/Sub, as Pub/Sub is not associated with any specific IP address or VPC network. Therefore, configuring VPC Service Controls with a perimeter around the VPC of project A would not prevent project B or any future project from accessing the data in the project A topic, if they have the necessary IAM roles and permissions.

Option B is not a good solution, as firewall rules are used to control the ingress and egress traffic to and from the VPC network of a project. Firewall rules do not apply to Pub/Sub, as Pub/Sub is not associated with any specific IP address or VPC network. Therefore, adding firewall rules in project A to only permit traffic from the VPC in project A would not prevent project B or any future project from accessing the data in the project A topic, if they have the necessary IAM roles and permissions.

Option C is not a good solution, as VPC Service Controls are designed to prevent data exfiltration from Google Cloud resources to the public internet, not to control access between Google Cloud projects. VPC Service Controls create a perimeter around the resources of one or more projects, and restrict the communication with resources outside the perimeter. However, VPC Service Controls do not apply to Pub/Sub, as Pub/Sub is not associated with any specific IP address or VPC network. Therefore, configuring VPC Service Controls with a perimeter around project A would not prevent project B or any future project from accessing the data in the project A topic, if they have the necessary IAM roles and permissions. References: Access control with IAM |Cloud Pub/Sub Documentation | Google Cloud, [Using IAM Conditions | Cloud IAMDocumentation | Google Cloud], [VPC Service Controls overview | Google Cloud], [Using VPC Service Controls | Google Cloud], [Pub/Sub tier capabilities | Memorystore for Redis | Google Cloud].

To resolve issues related to increased memory usage and worker pod evictions in your Cloud Composer 2 environment, the following steps are recommended:

Increase Memory Available to Airflow Workers:

By increasing the memory allocated to Airflow workers, you can handle more memory-intensive tasks, reducing the likelihood of pod evictions due to memory limits.

Increase Maximum Number of Workers and Reduce Worker Concurrency:

Increasing the number of workers allows the workload to be distributed across more pods, preventing any single pod from becoming overwhelmed.

Reducing worker concurrency limits the number of tasks that each worker can handle simultaneously, thereby lowering the memory consumption per worker.

Steps to Implement:

Increase Worker Memory:

Modify the configuration settings in Cloud Composer to allocate more memory to Airflow workers. This can be done through the environment configuration settings.

Adjust Worker and Concurrency Settings:

Increase the maximum number of workers in the Cloud Composer environment settings.

Reduce the concurrency setting for Airflow workers to ensure that each worker handles fewer tasks at a time, thus consuming less memory per worker.

Reference Links:

Cloud Composer Worker Configuration

Scaling Airflow Workers

To deploy a batch pipeline in Dataflow that adheres to the organizational constraint of using only internal IP addresses, ensuring Private Google Access is the most effective solution. Here’s why option D is the best choice:

Private Google Access:

Private Google Accessallows resources in a VPC network that do not have external IP addresses to access Google APIs and services through internal IP addresses.

This ensures compliance with the organizational constraint of using only internal IPs while allowing Dataflow to access Cloud Storage and BigQuery.

Dataflow with Internal IPs:

Dataflow can be configured to use only internal IP addresses for its worker nodes, ensuring that no external IP addresses are assigned.

This configuration ensures secure and compliant communication between Dataflow, Cloud Storage, and BigQuery.

Firewall and Network Configuration:

Enabling Private Google Access requires ensuring the correct firewall rules and network configurations to allow internal traffic to Google Cloud services.

Steps to Implement:

Enable Private Google Access:

Enable Private Google Access on the subnetwork used by the Dataflow pipeline

gcloud compute networks subnets update [SUBNET_NAME] \

--region [REGION] \

--enable-private-ip-google-access

Configure Dataflow:

Configure the Dataflow job to use only internal IP addresses

gcloud dataflow jobs run [JOB_NAME] \

--region [REGION] \

--network [VPC_NETWORK] \

--subnetwork [SUBNETWORK] \

--no-use-public-ips

Verify Access:

Ensure that firewall rules allow the necessary traffic from the Dataflow workers to Cloud Storage and BigQuery using internal IPs.

Reference Links:

Private Google Access Documentation

Configuring Dataflow to Use Internal IPs

VPC Firewall Rules

To ensure that the advertising department receives messages within 30 seconds of the click occurrence, and given the current system lag and data freshness metrics, the issue likely lies in the processing capacity of the Dataflow job. Here’s why option B is the best choice:

System Lag and Data Freshness:

The system lag of 5 seconds indicates that Dataflow itself is processing messages relatively quickly.

However, the data freshness of 40 seconds suggests a significant delay before processing begins, indicating a backlog.

Backlog in Pub/Sub Subscription:

A backlog occurs when the rate of incoming messages exceeds the rate at which the Dataflow job can process them, causing delays.

Optimizing the Dataflow Job:

To handle the incoming message rate, the Dataflow job needs to be optimized or scaled up by increasing the number of workers, ensuring it can keep up with the message inflow.

Steps to Implement:

Analyze the Dataflow Job:

Inspect the Dataflow job metrics to identify bottlenecks and inefficiencies.

Optimize Processing Logic:

Optimize the transformations and operations within the Dataflow pipeline to improve processing efficiency.

Increase Number of Workers:

Scale the Dataflow job by increasing the number of workers to handle the higher load, reducing the backlog.

Reference Links:

Dataflow Monitoring

Scaling Dataflow Jobs