Google Professional Data Engineer Practice Test 25
Question 240
The data engineering team must correct this issue: A fraud model reports 99 percent accuracy on data where only one in a thousand transactions is fraudulent. Which controlled engineering action is MOST appropriate?
- Evaluate the model using appropriate metrics and select a reviewed operating threshold.
- Apply an approved text-extraction and chunking pipeline with accuracy and privacy checks.
- Version reusable transformations and validate feature parity between training and serving.
- Build point-in-time-correct training examples and retrain with only eligible predictors.
Explanation
Correct Answer
A:Evaluate the model using appropriate metrics and select a reviewed operating threshold. This addresses the specific problem while respecting business and technical constraints. Validate it by checking: A held-out set shows acceptable fraud detection without overwhelming legitimate transactions. Imbalanced classification requires precision, recall, and business-cost analysis beyond accuracy.
Incorrect Answers
B:Apply an approved text-extraction and chunking pipeline with accuracy and privacy checks. This addresses a different situation: A records team ingests scanned PDFs for semantic search but indexes raw unreadable binary bytes as if they were meaningful text. The current scenario instead calls for the more directly applicable engineering action: Evaluate the model using appropriate metrics and select a reviewed operating threshold. The reason is that imbalanced classification requires precision, recall, and business-cost analysis beyond accuracy.
C:Version reusable transformations and validate feature parity between training and serving. This addresses a different situation: A production model receives categorical values in a format different from the BigQuery ML training transformations. The current scenario instead calls for the more directly applicable engineering action: Evaluate the model using appropriate metrics and select a reviewed operating threshold. The reason is that imbalanced classification requires precision, recall, and business-cost analysis beyond accuracy.
D:Build point-in-time-correct training examples and retrain with only eligible predictors. This addresses a different situation: A churn model trains on a cancellation timestamp that becomes known only after the customer leaves, producing unrealistic validation accuracy. The current scenario instead calls for the more directly applicable engineering action: Evaluate the model using appropriate metrics and select a reviewed operating threshold. The reason is that imbalanced classification requires precision, recall, and business-cost analysis beyond accuracy.
Question 241
The data engineering team must correct this issue: A finance warehouse needs recoverable reporting after regional disruption but keeps its only critical dataset in one region. Which controlled engineering action is MOST appropriate?
- Configure supported regional high availability and test application reconnection.
- Design and test a compatible cross-location recovery approach consistent with regulation.
- Quarantine bad partitions and replay validated source data through controlled transformations.
- Route writes through the supported transactional primary or managed failover endpoint with retry handling.
Explanation
Correct Answer
B:Design and test a compatible cross-location recovery approach consistent with regulation. This addresses the specific problem while respecting business and technical constraints. Validate it by checking: An isolated regional outage drill restores a representative report from the approved alternate data copy. Analytical recovery requires independently retained copies and known restore procedures that meet policy.
Incorrect Answers
A:Configure supported regional high availability and test application reconnection. This addresses a different situation: A production relational data source resides on a single-zone Cloud SQL instance and a zone outage stops all ingestion. The current scenario instead calls for the more directly applicable engineering action: Design and test a compatible cross-location recovery approach consistent with regulation. The reason is that analytical recovery requires independently retained copies and known restore procedures that meet policy.
C:Quarantine bad partitions and replay validated source data through controlled transformations. This addresses a different situation: An upstream vendor accidentally publishes a corrupted schema version and downstream totals become wrong before anyone notices. The current scenario instead calls for the more directly applicable engineering action: Design and test a compatible cross-location recovery approach consistent with regulation. The reason is that analytical recovery requires independently retained copies and known restore procedures that meet policy.
D:Route writes through the supported transactional primary or managed failover endpoint with retry handling. This addresses a different situation: An application routes financial writes to a stale read replica after primary failure, returning success before records are durably committed. The current scenario instead calls for the more directly applicable engineering action: Design and test a compatible cross-location recovery approach consistent with regulation. The reason is that analytical recovery requires independently retained copies and known restore procedures that meet policy.
Question 242
After applying the change, the team re-examines this condition: A customer-relationship API imposes quotas, but ingestion code launches thousands of concurrent requests during a nightly backfill. Which result BEST verifies the improvement?
- The report is complete by its business deadline without paying for idle streaming resources.
- A replayed burst produces anomaly alerts within the specified detection window.
- The complete backfill finishes within the source contract with no sustained throttling.
- A simulated burst is buffered and multiple consumers process messages without publisher timeouts.
Explanation
Correct Answer
C:The complete backfill finishes within the source contract with no sustained throttling. This measures the intended corrected behavior rather than only confirming a setting. Implemented action: Introduce bounded concurrency, checkpointed pagination, and exponential backoff with jitter. Pipeline design must respect source-system limits and use controlled retries or backoff.
Incorrect Answers
A:The report is complete by its business deadline without paying for idle streaming resources. This addresses a different situation: A monthly tax report is generated once per period, but architects propose a continuously running expensive streaming engine. The current scenario instead calls for the more directly applicable verification result: The complete backfill finishes within the source contract with no sustained throttling. The reason is that pipeline design must respect source-system limits and use controlled retries or backoff.
B:A replayed burst produces anomaly alerts within the specified detection window. This addresses a different situation: A payment service must detect suspicious transaction patterns within seconds rather than after overnight aggregation. The current scenario instead calls for the more directly applicable verification result: The complete backfill finishes within the source contract with no sustained throttling. The reason is that pipeline design must respect source-system limits and use controlled retries or backoff.
D:A simulated burst is buffered and multiple consumers process messages without publisher timeouts. This addresses a different situation: Thousands of store devices publish small events unpredictably, and downstream systems must process them independently without blocking publishers. The current scenario instead calls for the more directly applicable verification result: The complete backfill finishes within the source contract with no sustained throttling. The reason is that pipeline design must respect source-system limits and use controlled retries or backoff.
Question 243
A design review evaluates this situation: A warehouse stores years of events and most reports filter by event date and customer segment, but all queries scan the full table. Which shortcut should the team MOST specifically avoid?
- Treat all cache keys as permanently durable records and delete the primary database.
- Assume every PostgreSQL extension and performance characteristic is identical without testing.
- Partition by an unused field and assume every arbitrary query becomes cheaper.
- Expose every inspection document to anonymous readers to simplify offline synchronization.
Explanation
Correct Answer
C:Partition by an unused field and assume every arbitrary query becomes cheaper. This is the unsafe shortcut directly relevant to the stated system. A better approach is: Partition by the relevant date field and cluster on useful high-selectivity columns where appropriate. Why: Partitioning and clustering can reduce eligible BigQuery query scanning when aligned with predicates.
Incorrect Answers
A:Treat all cache keys as permanently durable records and delete the primary database. This addresses a different situation: An ecommerce service repeatedly looks up the same short-lived inventory recommendations and overwhelms its primary datastore during traffic peaks. The current scenario instead calls for the more directly applicable unsafe shortcut: Partition by an unused field and assume every arbitrary query becomes cheaper. The reason is that partitioning and clustering can reduce eligible BigQuery query scanning when aligned with predicates.
B:Assume every PostgreSQL extension and performance characteristic is identical without testing. This addresses a different situation: A PostgreSQL-compatible application has intensive operational transactions plus complex analytical queries and wants compatible managed performance options. The current scenario instead calls for the more directly applicable unsafe shortcut: Partition by an unused field and assume every arbitrary query becomes cheaper. The reason is that partitioning and clustering can reduce eligible BigQuery query scanning when aligned with predicates.
D:Expose every inspection document to anonymous readers to simplify offline synchronization. This addresses a different situation: A mobile field-work app stores flexible nested inspection documents and synchronizes changes through supported client libraries. The current scenario instead calls for the more directly applicable unsafe shortcut: Partition by an unused field and assume every arbitrary query becomes cheaper. The reason is that partitioning and clustering can reduce eligible BigQuery query scanning when aligned with predicates.
Question 244
The data engineering team must correct this issue: An engineer claims an exactly-once Dataflow pipeline makes arbitrary external API side effects impossible to duplicate. Which controlled engineering action is MOST appropriate?
- Evolve the schema compatibly or route incompatible versions through a governed mapping.
- Build idempotent or transactional external writes with stable business event keys.
- Use appropriately sized ephemeral Dataproc job clusters or serverless Spark execution.
- Adopt a supported Kafka-to-Google Cloud ingestion connector or bridge with measured delivery guarantees.
Explanation
Correct Answer
B:Build idempotent or transactional external writes with stable business event keys. This addresses the specific problem while respecting business and technical constraints. Validate it by checking: A forced retry does not create a duplicate invoice at the external system. Pipeline execution guarantees do not automatically make non-idempotent external side effects exactly once.
Incorrect Answers
A:Evolve the schema compatibly or route incompatible versions through a governed mapping. This addresses a different situation: A partner adds nested JSON attributes to events and downstream parsing jobs fail on unknown fields. The current scenario instead calls for the more directly applicable engineering action: Build idempotent or transactional external writes with stable business event keys. The reason is that pipeline execution guarantees do not automatically make non-idempotent external side effects exactly once.
C:Use appropriately sized ephemeral Dataproc job clusters or serverless Spark execution. This addresses a different situation: A once-weekly Spark transformation uses a permanently running Dataproc cluster that sits idle most of the week. The current scenario instead calls for the more directly applicable engineering action: Build idempotent or transactional external writes with stable business event keys. The reason is that pipeline execution guarantees do not automatically make non-idempotent external side effects exactly once.
D:Adopt a supported Kafka-to-Google Cloud ingestion connector or bridge with measured delivery guarantees. This addresses a different situation: A platform has existing Kafka producers and needs to introduce cloud analytics without rewriting every producer immediately. The current scenario instead calls for the more directly applicable engineering action: Build idempotent or transactional external writes with stable business event keys. The reason is that pipeline execution guarantees do not automatically make non-idempotent external side effects exactly once.
Question 245
The data engineering team must correct this issue: A pipeline triggers an invoice-export API and Airflow retries the task after a timeout, sending the same invoice twice. Which controlled engineering action is MOST appropriate?
- Use stable idempotency keys or transactional checkpoints before retrying external exports.
- Move scheduled execution to an approved service identity or supported transfer owner with monitoring.
- Implement a governed backfill workflow with bounded concurrent writes and reconciliation.
- Use a suitable Google Cloud Workflows definition for the small stateful service chain.
Explanation
Correct Answer
A:Use stable idempotency keys or transactional checkpoints before retrying external exports. This addresses the specific problem while respecting business and technical constraints. Validate it by checking: A forced timeout results in one effective invoice export despite multiple attempts. Orchestration retries must respect the idempotency of downstream actions.
Incorrect Answers
B:Move scheduled execution to an approved service identity or supported transfer owner with monitoring. This addresses a different situation: A recurring transformation runs under the credentials of a departed analyst and begins failing when the account is disabled. The current scenario instead calls for the more directly applicable engineering action: Use stable idempotency keys or transactional checkpoints before retrying external exports. The reason is that orchestration retries must respect the idempotency of downstream actions.
C:Implement a governed backfill workflow with bounded concurrent writes and reconciliation. This addresses a different situation: A historical backfill and regular hourly ingestion overlap on the same BigQuery partitions, creating conflicting writes. The current scenario instead calls for the more directly applicable engineering action: Use stable idempotency keys or transactional checkpoints before retrying external exports. The reason is that orchestration retries must respect the idempotency of downstream actions.
D:Use a suitable Google Cloud Workflows definition for the small stateful service chain. This addresses a different situation: A lightweight pipeline calls several managed service APIs in order with retry rules, but the team proposes maintaining an entire Airflow deployment for one request chain. The current scenario instead calls for the more directly applicable engineering action: Use stable idempotency keys or transactional checkpoints before retrying external exports. The reason is that orchestration retries must respect the idempotency of downstream actions.
Question 246
After applying the change, the team re-examines this condition: Business teams cannot identify which dataset is authoritative for customer retention because copies lack ownership and lineage. Which result BEST verifies the improvement?
- A representative transform can run in a second approved environment with predictable adjustments.
- The same reviewed pipeline source deploys to a permitted second region with valid regional resources.
- Users can identify the certified retention dataset and its upstream systems without guessing.
- A malformed vendor record stays in the landing layer and cannot silently corrupt executive metrics.
Explanation
Correct Answer
C:Users can identify the certified retention dataset and its upstream systems without guessing. This measures the intended corrected behavior rather than only confirming a setting. Implemented action: Register curated assets in an approved catalog with owners, business definitions, and lineage. Cataloging and lineage metadata support discoverability, stewardship, and trusted reuse.
Incorrect Answers
A:A representative transform can run in a second approved environment with predictable adjustments. This addresses a different situation: A data platform expects future multi-cloud processing, but its transformation logic is buried in manual console operations with no versioned definitions. The current scenario instead calls for the more directly applicable verification result: Users can identify the certified retention dataset and its upstream systems without guessing. The reason is that cataloging and lineage metadata support discoverability, stewardship, and trusted reuse.
B:The same reviewed pipeline source deploys to a permitted second region with valid regional resources. This addresses a different situation: A pipeline deployment hardcodes one project ID and dataset location into every query, blocking deployment into another approved region. The current scenario instead calls for the more directly applicable verification result: Users can identify the certified retention dataset and its upstream systems without guessing. The reason is that cataloging and lineage metadata support discoverability, stewardship, and trusted reuse.
D:A malformed vendor record stays in the landing layer and cannot silently corrupt executive metrics. This addresses a different situation: A company lands vendor extracts directly in curated datasets, making it impossible to distinguish unvalidated source values from approved metrics. The current scenario instead calls for the more directly applicable verification result: Users can identify the certified retention dataset and its upstream systems without guessing. The reason is that cataloging and lineage metadata support discoverability, stewardship, and trusted reuse.
Question 247
A Google Cloud architecture review finds: A finance department publishes unreviewed experiment tables to the company-wide BI directory and consumers treat them as financial statements. Which principle BEST explains the underlying data-engineering risk?
- Data publication should distinguish certified, governed outputs from exploratory drafts.
- Authorized views can expose filtered or aggregated analytical data subject to correct permissions.
- Row-level security can enforce tenant-scoped access when identity and policy design are correct.
- Sharing products need subscriber-level lifecycle management and accountable permissions.
Explanation
Correct Answer
A:Data publication should distinguish certified, governed outputs from exploratory drafts. This principle identifies the relevant workload or governance requirement. The engineer should first examine: Review lineage, approval records, data quality checks, and access destinations. A focused corrective action is: Create a controlled publication process for certified datasets and report definitions.
Incorrect Answers
B:Authorized views can expose filtered or aggregated analytical data subject to correct permissions. This addresses a different situation: A service provider exposes aggregate service quality metrics to customers but must not reveal individual employee work records. The current scenario instead calls for the more directly applicable principle: Data publication should distinguish certified, governed outputs from exploratory drafts. The reason is that data publication should distinguish certified, governed outputs from exploratory drafts.
C:Row-level security can enforce tenant-scoped access when identity and policy design are correct. This addresses a different situation: A SaaS analytics platform hosts multiple tenant records in one BigQuery table, and users may see only their organization's rows. The current scenario instead calls for the more directly applicable principle: Data publication should distinguish certified, governed outputs from exploratory drafts. The reason is that data publication should distinguish certified, governed outputs from exploratory drafts.
D:Sharing products need subscriber-level lifecycle management and accountable permissions. This addresses a different situation: A business data provider wants to revoke a partner's access to an outdated analytics feed without invalidating access for other subscribers. The current scenario instead calls for the more directly applicable principle: Data publication should distinguish certified, governed outputs from exploratory drafts. The reason is that data publication should distinguish certified, governed outputs from exploratory drafts.
Question 248
After applying the change, the team re-examines this condition: An IoT pipeline joins fast sensor events to slowly changing asset ownership records and occasionally labels readings with obsolete owners. Which result BEST verifies the improvement?
- The report is complete by its business deadline without paying for idle streaming resources.
- A sample event uses the owner that was effective at its business event time.
- A test plaintext or unauthenticated request is rejected and approved ingestion succeeds.
- Re-delivering a file yields a traceable duplicate decision without overwriting certified data.
Explanation
Correct Answer
B:A sample event uses the owner that was effective at its business event time. This measures the intended corrected behavior rather than only confirming a setting. Implemented action: Implement versioned reference lookups or temporal enrichment with explicit validity periods. Stream enrichment requires a defined temporal join and lookup freshness contract.
Incorrect Answers
A:The report is complete by its business deadline without paying for idle streaming resources. This addresses a different situation: A monthly tax report is generated once per period, but architects propose a continuously running expensive streaming engine. The current scenario instead calls for the more directly applicable verification result: A sample event uses the owner that was effective at its business event time. The reason is that stream enrichment requires a defined temporal join and lookup freshness contract.
C:A test plaintext or unauthenticated request is rejected and approved ingestion succeeds. This addresses a different situation: A partner uploads raw customer records by custom API, but the team has not assessed encryption in transit or destination access. The current scenario instead calls for the more directly applicable verification result: A sample event uses the owner that was effective at its business event time. The reason is that stream enrichment requires a defined temporal join and lookup freshness contract.
D:Re-delivering a file yields a traceable duplicate decision without overwriting certified data. This addresses a different situation: Daily vendor deliveries contain multipart files with duplicate names and changing schemas, making ingestion traceability unreliable. The current scenario instead calls for the more directly applicable verification result: A sample event uses the owner that was effective at its business event time. The reason is that stream enrichment requires a defined temporal join and lookup freshness contract.
Question 249
A Google Cloud data engineer is addressing: A records team ingests scanned PDFs for semantic search but indexes raw unreadable binary bytes as if they were meaningful text. Which TWO complementary actions should the team take? Select TWO answers.
- Inspect document types, OCR quality, extracted text, language detection, and document access.
- Inspect feature timestamps, training joins, holdout splits, and online availability.
- Record versioned model artifacts and approval criteria with reproducible training inputs.
- Review source freshness, chunk boundaries, embedding model, ACLs, and retrieval quality.
- Apply an approved text-extraction and chunking pipeline with accuracy and privacy checks.
Explanation
Correct Answers
A:Inspect document types, OCR quality, extracted text, language detection, and document access. This is the applicable diagnostic investigation. Its complementary step is: Apply an approved text-extraction and chunking pipeline with accuracy and privacy checks. Together they address: Unstructured analytics needs extraction, validation, and meaningful text segmentation before embedding.
E:Apply an approved text-extraction and chunking pipeline with accuracy and privacy checks. This is the applicable controlled engineering response. Its complementary step is: Inspect document types, OCR quality, extracted text, language detection, and document access. Together they address: Unstructured analytics needs extraction, validation, and meaningful text segmentation before embedding.
Incorrect Answers
B:Inspect feature timestamps, training joins, holdout splits, and online availability. This could be useful for another system: A churn model trains on a cancellation timestamp that becomes known only after the customer leaves, producing unrealistic validation accuracy. For this situation, the necessary paired decisions are to examine (Inspect document types, OCR quality, extracted text, language detection, and document access.) and to implement (Apply an approved text-extraction and chunking pipeline with accuracy and privacy checks.).
C:Record versioned model artifacts and approval criteria with reproducible training inputs. This could be useful for another system: A data scientist overwrites a BigQuery ML model each week and has no record of which training window produced the current predictions. For this situation, the necessary paired decisions are to examine (Inspect document types, OCR quality, extracted text, language detection, and document access.) and to implement (Apply an approved text-extraction and chunking pipeline with accuracy and privacy checks.).
D:Review source freshness, chunk boundaries, embedding model, ACLs, and retrieval quality. This could be useful for another system: A customer-service assistant needs grounded retrieval from updated knowledge articles, but the current index mixes old and current documents without lineage. For this situation, the necessary paired decisions are to examine (Inspect document types, OCR quality, extracted text, language detection, and document access.) and to implement (Apply an approved text-extraction and chunking pipeline with accuracy and privacy checks.).
Question 250
A Google Cloud data engineer is addressing: A vehicle telemetry stream might need replay after an outage, but source retention expires sooner than the required recovery window. Which TWO complementary actions should the team take? Select TWO answers.
- Inspect Pub/Sub retention settings, expected outage duration, legal retention, and storage cost.
- Review API quotas, response headers, batch windows, and rate-limit failures.
- Configure appropriate message retention or raw event archival for replay and recovery.
- Use Pub/Sub topics and independently scaled subscriptions with monitored consumers.
- Inspect object names, source timestamps, hash manifests, schemas, and duplicate deliveries.
Explanation
Correct Answers
A:Inspect Pub/Sub retention settings, expected outage duration, legal retention, and storage cost. This is the applicable diagnostic investigation. Its complementary step is: Configure appropriate message retention or raw event archival for replay and recovery. Together they address: Replay and recovery objectives depend on source retention and durable staging choices.
C:Configure appropriate message retention or raw event archival for replay and recovery. This is the applicable controlled engineering response. Its complementary step is: Inspect Pub/Sub retention settings, expected outage duration, legal retention, and storage cost. Together they address: Replay and recovery objectives depend on source retention and durable staging choices.
Incorrect Answers
B:Review API quotas, response headers, batch windows, and rate-limit failures. This could be useful for another system: A customer-relationship API imposes quotas, but ingestion code launches thousands of concurrent requests during a nightly backfill. For this situation, the necessary paired decisions are to examine (Inspect Pub/Sub retention settings, expected outage duration, legal retention, and storage cost.) and to implement (Configure appropriate message retention or raw event archival for replay and recovery.).
D:Use Pub/Sub topics and independently scaled subscriptions with monitored consumers. This could be useful for another system: Thousands of store devices publish small events unpredictably, and downstream systems must process them independently without blocking publishers. For this situation, the necessary paired decisions are to examine (Inspect Pub/Sub retention settings, expected outage duration, legal retention, and storage cost.) and to implement (Configure appropriate message retention or raw event archival for replay and recovery.).
E:Inspect object names, source timestamps, hash manifests, schemas, and duplicate deliveries. This could be useful for another system: Daily vendor deliveries contain multipart files with duplicate names and changing schemas, making ingestion traceability unreliable. For this situation, the necessary paired decisions are to examine (Inspect Pub/Sub retention settings, expected outage duration, legal retention, and storage cost.) and to implement (Configure appropriate message retention or raw event archival for replay and recovery.).