PDE Storing the Data Practice Test 3 — 15 Questions

Question 1

A company wants to implement a data lake on Google Cloud. They need to store raw, structured data in open formats and allow querying directly from BigQuery without loading. Which TWO services or features should they use? (Choose 2)

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

Accepted Answer

Cloud Storage (GCS). Cloud Storage (GCS) serves as the scalable, cost-effective storage layer for raw data in open formats such as Parquet, Avro, or ORC. BigLake enables BigQuery to directly query this data without loading it, providing a unified lakehouse experience. Dataproc can be used to transform and convert data into open formats before storing in GCS, completing the data lake architecture. Together, these three services enable storing raw structured data and querying it directly from BigQuery without the need to load data into BigQuery storage.

Answer

Dataproc

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Dataflow

Answer

Cloud SQL

Question 2

A company stores sensitive data in BigQuery and Cloud Storage. They must encrypt data with customer-managed keys and restrict access to the encryption keys to only a specific VPC network. Which THREE components should they configure? (Choose 3)

Accepted Answer

VPC Service Controls. VPC Service Controls (A) is correct because it allows you to define a security perimeter around BigQuery and Cloud Storage, restricting access to these services from only a specific VPC network. This ensures that even if an attacker obtains valid credentials, they cannot access the data from outside the authorized VPC, which is essential for limiting encryption key access to the designated network. Cloud HSM (B) is correct because it provides Hardware Security Module-backed key storage, which is often required for compliance when using customer-managed keys. Cloud KMS with a customer-managed key (C) is correct because it enables you to use your own encryption keys to protect data at rest in BigQuery and Cloud Storage. By combining Cloud HSM and CMEK with VPC Service Controls, you can both encrypt data with your own keys and restrict access to those keys to a specific VPC network.

Answer

Identity-Aware Proxy (IAP)

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Cloud Armor

Question 3

A company needs a fully managed, globally distributed relational database with strong consistency, external consistency, and 99.999% SLA for a financial transaction processing system. Which Google Cloud service should they use?

Accepted Answer

Cloud Spanner. Cloud Spanner is the correct choice because it is a fully managed, globally distributed relational database service that provides strong consistency, external consistency (true serializable transactions across regions), and a 99.999% SLA. These features are essential for a financial transaction processing system that requires ACID compliance and global scalability without sacrificing consistency.

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Firestore

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Bigtable

Answer

Cloud SQL

Question 4

A data engineer needs to store raw sensor data in Cloud Storage and automatically transition it to a lower-cost storage class after 30 days, then delete it after 365 days. What should they configure?

Accepted Answer

Configure a lifecycle rule with SetStorageClass to Nearline after 30 days and Delete after 365 days.. Cloud Storage lifecycle management rules allow you to automatically transition objects to a lower-cost storage class (such as Nearline) after a specified number of days and then delete them after another period. This is the native, serverless way to manage object lifecycle without external scripts or compute resources.

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Use Cloud Pub/Sub notifications to trigger a Cloud Function that moves objects.

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Use gsutil rewrite command in a cron job.

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Set a bucket retention policy with a retention period of 365 days.

Question 5

A data engineer is building a data lake on Google Cloud and needs to separate raw ingested data, curated/cleaned data, and processed/aggregated data. Which Cloud Storage bucket structure is recommended?

Accepted Answer

Create three separate folders in a single bucket: raw, curated, processed.. A common best practice for data lakes on GCS is to use separate buckets or folders within a bucket (e.g., raw, curated, processed) to manage different stages of data refinement and apply appropriate lifecycle policies.

Answer

Store all data in one bucket and use object labels to distinguish raw, curated, and processed.

Answer

Store raw data in a different project for security isolation.

Answer

Use different storage classes for raw, curated, and processed data within the same bucket.

Question 6

A mobile app needs an offline-first NoSQL database that syncs data across devices when connectivity is available. Which Google Cloud database meets these requirements?

Accepted Answer

Firestore. Firestore is a NoSQL, serverless, offline-first database that automatically syncs data across devices when connectivity is restored. It provides built-in offline persistence and real-time synchronization, making it ideal for mobile apps that need to work offline and sync later.

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Memorystore

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Cloud SQL

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Bigtable

Question 7

An organization needs to prevent data exfiltration from BigQuery by ensuring all traffic to BigQuery APIs goes through VPC boundaries and is restricted to a specific service perimeter. Which Google Cloud security control should they use?

Accepted Answer

VPC Service Controls. VPC Service Controls (D) is the correct answer because it allows you to define a service perimeter around BigQuery APIs, ensuring that all traffic to BigQuery must originate from within the defined VPC boundaries. This prevents data exfiltration by blocking unauthorized access from outside the perimeter, even if valid credentials are used. It works by enforcing context-aware access policies at the Google Cloud network edge, not at the application layer.

Answer

Access Transparency

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IAM conditions on BigQuery roles

Answer

Cloud Armor

Question 8

A data engineer needs to design a Bigtable row key for a time-series IoT application where each device sends data every second. The query pattern is to retrieve all data for a specific device over a time range. Which row key design minimizes hotspots?

Accepted Answer

hash(device_id)#timestamp (e.g., a3f2#2024-03-15-10:30:00). To avoid hotspots (where all writes hit a single tablet server), the row key should start with a hash of the device ID to distribute writes across the cluster, then append the timestamp for range scans.

Answer

device_id#timestamp (e.g., device123#2024-03-15-10:30:00)

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timestamp#device_id (e.g., 2024-03-15-10:30:00#device123)

Answer

device_type#device_id#timestamp

Question 9

A company wants to use BigQuery to query data stored in Parquet files in Cloud Storage without loading the data into BigQuery. Which BigQuery feature should they use?

Accepted Answer

BigQuery external tables. BigQuery external tables allow querying data stored in Cloud Storage (including Parquet files) directly without loading it into BigQuery storage. This feature uses a federated query engine that reads the data on the fly, supporting formats like Parquet, Avro, ORC, CSV, and JSON. Option C is correct because it directly addresses the requirement to query Parquet files in Cloud Storage without ingestion.

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BigQuery Omni

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BigQuery ML

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BigQuery BI Engine

Question 10

A Cloud SQL instance for PostgreSQL is experiencing heavy read traffic. The team wants to offload read queries while maintaining data consistency. Which solution meets their needs?

Accepted Answer

Create read replicas and direct read queries to them.. Read replicas in Cloud SQL for PostgreSQL allow you to offload read traffic from the primary instance by creating one or more asynchronous replicas that serve read queries. This maintains data consistency because replicas use PostgreSQL's native streaming replication, ensuring that all committed transactions on the primary are eventually reflected on the replica, providing a consistent snapshot for read operations.

Answer

Increase the tier of the Cloud SQL instance.

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Create a Cloud SQL failover replica.

Answer

Use Cloud Memorystore as a cache in front of Cloud SQL.

Question 11

A data team needs to run complex analytical queries on a dataset that is frequently updated with new rows. They want to minimize query costs and avoid scanning old data that is rarely queried. Which BigQuery feature should they use?

Accepted Answer

Partitioned tables with partition expiration. Partitioned tables with partition expiration allow you to divide a table into segments based on a date/timestamp column, and automatically delete partitions that are older than a specified duration. This minimizes query costs by only scanning relevant partitions and eliminates storage costs for old, rarely queried data without manual intervention.

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BigQuery materialized views

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Clustered tables

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BigQuery BI Engine

Question 12

A data engineer needs to create a unified table that combines data from Cloud Storage (Parquet files) and BigQuery native tables, with fine-grained access control and governance. Which three Google Cloud features should they use together? (Choose THREE.)

Accepted Answer

BigQuery. BigQuery is correct because it serves as the unified query engine that can read data from both Cloud Storage (via external tables or BigLake) and native BigQuery tables, enabling a single SQL interface for analysis. It also integrates with fine-grained access control through row-level security and column-level access policies, and supports governance via Data Catalog and VPC Service Controls.

Answer

Dataproc

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Cloud SQL

Question 13

A company needs to store and analyze large amounts of unstructured data (images, videos) and structured data (CSV logs) in a cost-effective manner. The data should be accessible for analytics with BigQuery. Which two services should they use? (Choose TWO.)

Accepted Answer

BigQuery. Cloud Storage is the best option for storing unstructured and structured files cost-effectively. BigQuery can analyze this data directly via external tables or after loading, making it a powerful analytics platform.

Answer

Cloud SQL

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Cloud Spanner

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Firestore

Question 14

A team needs to store transactional data for an e-commerce application that requires ACID transactions, automatic backups, and point-in-time recovery. The expected workload is under 10,000 QPS. Which database should they choose?

Accepted Answer

Cloud SQL. Cloud SQL is the correct choice because it provides fully managed relational databases (MySQL, PostgreSQL, SQL Server) with built-in ACID transaction support, automated backups, and point-in-time recovery (PITR) via binary logs or write-ahead logs. The workload of under 10,000 QPS is well within Cloud SQL's performance envelope, making it a cost-effective and operationally simple solution for transactional e-commerce data.

Answer

Cloud Bigtable

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Firestore

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Cloud Spanner

Question 15

An application requires a globally distributed, strongly consistent database with 99.999% availability SLA. The workload is OLTP with high throughput across continents. Which service fits best?

Accepted Answer

Cloud Spanner. Cloud Spanner is the only service that provides globally distributed, strongly consistent (external consistency via TrueTime) OLTP with 99.999% availability SLA. It supports high-throughput ACID transactions across continents using synchronous replication and atomic clocks, meeting all stated requirements.

Answer

Cloud SQL with cross-region replicas

Answer

Firestore

Answer

Cloud Bigtable