Google Professional Data Engineer Practice Test 35
Question 340
A Google Cloud architecture review finds: A platform has steady high-volume SQL demand but is paying unpredictable per-query cost while finance requires capacity budgets. Which principle BEST explains the underlying data-engineering risk?
- Capacity pricing and reservations should be evaluated against measured utilization and service commitments.
- Query cost control starts with bytes processed, filters, and selecting only required columns.
- Job priority and capacity policies should reflect latency sensitivity and business importance.
- Flexible capacity and assignment strategies can isolate occasional bursts without starving core reporting.
Explanation
Correct Answer
A:Capacity pricing and reservations should be evaluated against measured utilization and service commitments. This principle identifies the relevant workload or governance requirement. The engineer should first examine: Analyze historical slot use, edition features, on-demand costs, and commitment terms. A focused corrective action is: Model an appropriate BigQuery Editions capacity reservation with planned commitments.
Incorrect Answers
B:Query cost control starts with bytes processed, filters, and selecting only required columns. This addresses a different situation: A reporting application repeatedly runs SELECT star against a wide event table and billing spikes even though it needs five fields. The current scenario instead calls for the more directly applicable principle: Capacity pricing and reservations should be evaluated against measured utilization and service commitments. The reason is that capacity pricing and reservations should be evaluated against measured utilization and service commitments.
C:Job priority and capacity policies should reflect latency sensitivity and business importance. This addresses a different situation: A same-day executive dashboard competes with a large nonurgent nightly historical rebuild. The current scenario instead calls for the more directly applicable principle: Capacity pricing and reservations should be evaluated against measured utilization and service commitments. The reason is that capacity pricing and reservations should be evaluated against measured utilization and service commitments.
D:Flexible capacity and assignment strategies can isolate occasional bursts without starving core reporting. This addresses a different situation: A data science team needs occasional huge feature-engineering runs but competes with a permanently reserved reporting workload. The current scenario instead calls for the more directly applicable principle: Capacity pricing and reservations should be evaluated against measured utilization and service commitments. The reason is that capacity pricing and reservations should be evaluated against measured utilization and service commitments.
Question 341
After applying the change, the team re-examines this condition: A popular dashboard repeatedly computes the same large daily summary with strict latency goals, while raw transactional records remain necessary for detail drill-down. Which result BEST verifies the improvement?
- A small daily update changes only relevant partitions and leaves historical totals correct.
- A prior-period report retains the historical customer tier after a new tier change.
- A test report counts orders and line items correctly without multiplying unrelated measures.
- Typical dashboards use the optimized summary and reconcile with detailed raw measures.
Explanation
Correct Answer
D:Typical dashboards use the optimized summary and reconcile with detailed raw measures. This measures the intended corrected behavior rather than only confirming a setting. Implemented action: Evaluate an eligible materialized view or governed summary table for common aggregates. Precomputed summary structures can improve repeated analytical response time where refresh limits and query patterns fit.
Incorrect Answers
A:A small daily update changes only relevant partitions and leaves historical totals correct. This addresses a different situation: A daily fact table receives corrections, but each load recomputes every historical year and causes excessive query cost. The current scenario instead calls for the more directly applicable verification result: Typical dashboards use the optimized summary and reconcile with detailed raw measures. The reason is that precomputed summary structures can improve repeated analytical response time where refresh limits and query patterns fit.
B:A prior-period report retains the historical customer tier after a new tier change. This addresses a different situation: Customer account tiers change over time but year-old invoices must be reported using the tier effective at the invoice date. The current scenario instead calls for the more directly applicable verification result: Typical dashboards use the optimized summary and reconcile with detailed raw measures. The reason is that precomputed summary structures can improve repeated analytical response time where refresh limits and query patterns fit.
C:A test report counts orders and line items correctly without multiplying unrelated measures. This addresses a different situation: An events schema contains orders with many line items and analysts often query an order together with its items as one logical document. The current scenario instead calls for the more directly applicable verification result: Typical dashboards use the optimized summary and reconcile with detailed raw measures. The reason is that precomputed summary structures can improve repeated analytical response time where refresh limits and query patterns fit.
Question 342
A Google Cloud data engineer is addressing: Developers test destructive transformations against the same production dataset used for regulatory reporting. Which TWO complementary actions should the team take? Select TWO answers.
- Create the approved regional KMS key and configure eligible BigQuery storage to use it with scoped service-agent access.
- Inspect projects, dataset names, service-account scopes, deployment permissions, and audit activity.
- Select compliant regional resources and constrain replication, jobs, and exports to approved locations.
- Create isolated nonproduction projects and datasets with masked test fixtures and deployment gates.
- Examine Cloud Audit Logs configuration, data access log coverage, export job history, and retention.
Explanation
Correct Answers
B:Inspect projects, dataset names, service-account scopes, deployment permissions, and audit activity. This is the applicable diagnostic investigation. Its complementary step is: Create isolated nonproduction projects and datasets with masked test fixtures and deployment gates. Together they address: Separate development and production boundaries limit the impact of exploratory and destructive data operations.
D:Create isolated nonproduction projects and datasets with masked test fixtures and deployment gates. This is the applicable controlled engineering response. Its complementary step is: Inspect projects, dataset names, service-account scopes, deployment permissions, and audit activity. Together they address: Separate development and production boundaries limit the impact of exploratory and destructive data operations.
Incorrect Answers
A:Create the approved regional KMS key and configure eligible BigQuery storage to use it with scoped service-agent access. This could be useful for another system: A regulated finance team requires customer-managed keys for sensitive BigQuery tables and documented key revocation procedures. For this situation, the necessary paired decisions are to examine (Inspect projects, dataset names, service-account scopes, deployment permissions, and audit activity.) and to implement (Create isolated nonproduction projects and datasets with masked test fixtures and deployment gates.).
C:Select compliant regional resources and constrain replication, jobs, and exports to approved locations. This could be useful for another system: A European customer contract restricts processing and storage to approved locations, while engineers intend to replicate datasets to another continent. For this situation, the necessary paired decisions are to examine (Inspect projects, dataset names, service-account scopes, deployment permissions, and audit activity.) and to implement (Create isolated nonproduction projects and datasets with masked test fixtures and deployment gates.).
E:Examine Cloud Audit Logs configuration, data access log coverage, export job history, and retention. This could be useful for another system: A compliance team cannot determine which identity exported a restricted BigQuery customer table last week. For this situation, the necessary paired decisions are to examine (Inspect projects, dataset names, service-account scopes, deployment permissions, and audit activity.) and to implement (Create isolated nonproduction projects and datasets with masked test fixtures and deployment gates.).
Question 343
A Google Cloud data engineer is addressing: A regional processing failure stops daily regulatory datasets because all staging, computation, and recovery copies reside in one failure domain. Which TWO complementary actions should the team take? Select TWO answers.
- Implement deterministic event-key deduplication or idempotent sink semantics with an appropriate replay window.
- Review RPO/RTO requirements, region dependencies, replication design, and backup restoration tests.
- Implement an approved multi-location or recoverable regional design with tested failover and data reconciliation.
- Choose a supported transactional database design and execute related mutations in governed transactions.
- Examine event times, source priority, change sequence, and BigQuery merge logic.
Explanation
Correct Answers
B:Review RPO/RTO requirements, region dependencies, replication design, and backup restoration tests. This is the applicable diagnostic investigation. Its complementary step is: Implement an approved multi-location or recoverable regional design with tested failover and data reconciliation. Together they address: Recovery objectives should drive resilient data placement, backups, and executable failover procedures.
C:Implement an approved multi-location or recoverable regional design with tested failover and data reconciliation. This is the applicable controlled engineering response. Its complementary step is: Review RPO/RTO requirements, region dependencies, replication design, and backup restoration tests. Together they address: Recovery objectives should drive resilient data placement, backups, and executable failover procedures.
Incorrect Answers
A:Implement deterministic event-key deduplication or idempotent sink semantics with an appropriate replay window. This could be useful for another system: A payments stream retries messages after transient failures, causing duplicate warehouse revenue rows during replay. For this situation, the necessary paired decisions are to examine (Review RPO/RTO requirements, region dependencies, replication design, and backup restoration tests.) and to implement (Implement an approved multi-location or recoverable regional design with tested failover and data reconciliation.).
D:Choose a supported transactional database design and execute related mutations in governed transactions. This could be useful for another system: An order service needs multi-row transactional correctness, yet engineers propose independent uncoordinated object writes as the system of record. For this situation, the necessary paired decisions are to examine (Review RPO/RTO requirements, region dependencies, replication design, and backup restoration tests.) and to implement (Implement an approved multi-location or recoverable regional design with tested failover and data reconciliation.).
E:Examine event times, source priority, change sequence, and BigQuery merge logic. This could be useful for another system: A reporting table is updated from multiple partners, and records arriving days late overwrite newer authoritative versions. For this situation, the necessary paired decisions are to examine (Review RPO/RTO requirements, region dependencies, replication design, and backup restoration tests.) and to implement (Implement an approved multi-location or recoverable regional design with tested failover and data reconciliation.).
Question 344
After applying the change, the team re-examines this condition: A payments stream retries messages after transient failures, causing duplicate warehouse revenue rows during replay. Which result BEST verifies the improvement?
- A generated accidental DELETE statement cannot modify protected production tables.
- An injected worker failure recovers processing without missing or double-counting committed events.
- A deliberately interrupted order update cannot leave mutually inconsistent committed rows.
- Replaying the same business event does not increase recognized revenue a second time.
Explanation
Correct Answer
D:Replaying the same business event does not increase recognized revenue a second time. This measures the intended corrected behavior rather than only confirming a setting. Implemented action: Implement deterministic event-key deduplication or idempotent sink semantics with an appropriate replay window. At-least-once message delivery requires explicit idempotency and stable event identity in downstream processing.
Incorrect Answers
A:A generated accidental DELETE statement cannot modify protected production tables. This addresses a different situation: An analytics team uses LLM-generated BigQuery SQL and executes it immediately against production tables with write privileges. The current scenario instead calls for the more directly applicable verification result: Replaying the same business event does not increase recognized revenue a second time. The reason is that at-least-once message delivery requires explicit idempotency and stable event identity in downstream processing.
B:An injected worker failure recovers processing without missing or double-counting committed events. This addresses a different situation: A six-hour streaming Dataflow job is relaunched after worker failure and loses uncommitted state when operators create a new pipeline without recovery planning. The current scenario instead calls for the more directly applicable verification result: Replaying the same business event does not increase recognized revenue a second time. The reason is that at-least-once message delivery requires explicit idempotency and stable event identity in downstream processing.
C:A deliberately interrupted order update cannot leave mutually inconsistent committed rows. This addresses a different situation: An order service needs multi-row transactional correctness, yet engineers propose independent uncoordinated object writes as the system of record. The current scenario instead calls for the more directly applicable verification result: Replaying the same business event does not increase recognized revenue a second time. The reason is that at-least-once message delivery requires explicit idempotency and stable event identity in downstream processing.
Question 345
The data engineering team must correct this issue: A customer-relationship API imposes quotas, but ingestion code launches thousands of concurrent requests during a nightly backfill. Which controlled engineering action is MOST appropriate?
- Use a scheduled batch processing workflow with timely validated delivery for monthly reporting.
- Introduce bounded concurrency, checkpointed pagination, and exponential backoff with jitter.
- Configure appropriate message retention or raw event archival for replay and recovery.
- Adopt versioned landing paths and idempotent manifest processing before transformation.
Explanation
Correct Answer
B:Introduce bounded concurrency, checkpointed pagination, and exponential backoff with jitter. This addresses the specific problem while respecting business and technical constraints. Validate it by checking: The complete backfill finishes within the source contract with no sustained throttling. Pipeline design must respect source-system limits and use controlled retries or backoff.
Incorrect Answers
A:Use a scheduled batch processing workflow with timely validated delivery for monthly reporting. 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 engineering action: Introduce bounded concurrency, checkpointed pagination, and exponential backoff with jitter. The reason is that pipeline design must respect source-system limits and use controlled retries or backoff.
C:Configure appropriate message retention or raw event archival for replay and recovery. This addresses a different situation: A vehicle telemetry stream might need replay after an outage, but source retention expires sooner than the required recovery window. The current scenario instead calls for the more directly applicable engineering action: Introduce bounded concurrency, checkpointed pagination, and exponential backoff with jitter. The reason is that pipeline design must respect source-system limits and use controlled retries or backoff.
D:Adopt versioned landing paths and idempotent manifest processing before transformation. 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 engineering action: Introduce bounded concurrency, checkpointed pagination, and exponential backoff with jitter. The reason is that pipeline design must respect source-system limits and use controlled retries or backoff.
Question 346
The data engineering team must correct this issue: A partner adds nested JSON attributes to events and downstream parsing jobs fail on unknown fields. Which controlled engineering action is MOST appropriate?
- Redesign the aggregation key or introduce valid fan-out patterns where supported.
- Use appropriately sized ephemeral Dataproc job clusters or serverless Spark execution.
- Use a validated staging table and deterministic BigQuery MERGE logic with deduplicated keys.
- Evolve the schema compatibly or route incompatible versions through a governed mapping.
Explanation
Correct Answer
D:Evolve the schema compatibly or route incompatible versions through a governed mapping. This addresses the specific problem while respecting business and technical constraints. Validate it by checking: Old and new supported event versions are processed without hidden loss of required fields. Streaming schemas need compatibility rules and controlled unknown-field behavior.
Incorrect Answers
A:Redesign the aggregation key or introduce valid fan-out patterns where supported. This addresses a different situation: A Dataflow group-by-key stage slows because almost all events share one constant grouping value. The current scenario instead calls for the more directly applicable engineering action: Evolve the schema compatibly or route incompatible versions through a governed mapping. The reason is that streaming schemas need compatibility rules and controlled unknown-field behavior.
B: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: Evolve the schema compatibly or route incompatible versions through a governed mapping. The reason is that streaming schemas need compatibility rules and controlled unknown-field behavior.
C:Use a validated staging table and deterministic BigQuery MERGE logic with deduplicated keys. This addresses a different situation: A nightly BigQuery MERGE job occasionally reruns after an orchestrator timeout and inserts duplicate business keys. The current scenario instead calls for the more directly applicable engineering action: Evolve the schema compatibly or route incompatible versions through a governed mapping. The reason is that streaming schemas need compatibility rules and controlled unknown-field behavior.
Question 347
A Google Cloud architecture review finds: A large Spark cluster remains at peak worker count during long idle stages because autoscaling is disabled. Which principle BEST explains the underlying data-engineering risk?
- Storage-class economics include retrieval fees and minimum duration, not only price per stored GB.
- Worker cost optimization must follow actual pipeline parallelism and bottlenecks.
- Compute capacity management should reflect distinct workloads and measured slot demand.
- Elastic batch processing should match provisioned workers to actual parallel workload demand.
Explanation
Correct Answer
D:Elastic batch processing should match provisioned workers to actual parallel workload demand. This principle identifies the relevant workload or governance requirement. The engineer should first examine: Inspect Dataproc CPU usage, YARN metrics, cluster autoscaling settings, and job boundaries. A focused corrective action is: Apply a supported autoscaling policy or job-based execution with performance safeguards.
Incorrect Answers
A:Storage-class economics include retrieval fees and minimum duration, not only price per stored GB. This addresses a different situation: A media archive changes every object to the coldest storage class even though analysts read recent objects daily. The current scenario instead calls for the more directly applicable principle: Elastic batch processing should match provisioned workers to actual parallel workload demand. The reason is that elastic batch processing should match provisioned workers to actual parallel workload demand.
B:Worker cost optimization must follow actual pipeline parallelism and bottlenecks. This addresses a different situation: A Dataflow batch pipeline processes a few large files using hundreds of workers while bottlenecked on one serialized source stage. The current scenario instead calls for the more directly applicable principle: Elastic batch processing should match provisioned workers to actual parallel workload demand. The reason is that elastic batch processing should match provisioned workers to actual parallel workload demand.
C:Compute capacity management should reflect distinct workloads and measured slot demand. This addresses a different situation: Critical dashboards compete with scheduled ETL jobs for BigQuery slots and miss interactive latency targets. The current scenario instead calls for the more directly applicable principle: Elastic batch processing should match provisioned workers to actual parallel workload demand. The reason is that elastic batch processing should match provisioned workers to actual parallel workload demand.
Question 348
After applying the change, the team re-examines this condition: A payment service must detect suspicious transaction patterns within seconds rather than after overnight aggregation. Which result BEST verifies the improvement?
- The complete backfill finishes within the source contract with no sustained throttling.
- A replayed burst produces anomaly alerts within the specified detection window.
- A source extract reaches the authorized destination without exposing an unauthenticated public endpoint.
- A replay preserves required per-customer sequence without claiming global order.
Explanation
Correct Answer
B:A replayed burst produces anomaly alerts within the specified detection window. This measures the intended corrected behavior rather than only confirming a setting. Implemented action: Use Pub/Sub and an appropriately configured Dataflow stream with an approved low-latency sink. Low-latency operational analytics need a streaming path with bounded end-to-end delay.
Incorrect Answers
A:The complete backfill finishes within the source contract with no sustained throttling. This addresses a different situation: A customer-relationship API imposes quotas, but ingestion code launches thousands of concurrent requests during a nightly backfill. The current scenario instead calls for the more directly applicable verification result: A replayed burst produces anomaly alerts within the specified detection window. The reason is that low-latency operational analytics need a streaming path with bounded end-to-end delay.
C:A source extract reaches the authorized destination without exposing an unauthenticated public endpoint. This addresses a different situation: An internal ERP system sends sensitive database extracts to Google Cloud but security rules prohibit unrestricted internet endpoints. The current scenario instead calls for the more directly applicable verification result: A replayed burst produces anomaly alerts within the specified detection window. The reason is that low-latency operational analytics need a streaming path with bounded end-to-end delay.
D:A replay preserves required per-customer sequence without claiming global order. This addresses a different situation: A product team requires per-customer event ordering but distributes all messages without a stable key and assumes total ordering across workers. The current scenario instead calls for the more directly applicable verification result: A replayed burst produces anomaly alerts within the specified detection window. The reason is that low-latency operational analytics need a streaming path with bounded end-to-end delay.
Question 349
A Google Cloud data engineer is addressing: A fraud model reports 99 percent accuracy on data where only one in a thousand transactions is fraudulent. Which TWO complementary actions should the team take? Select TWO answers.
- Review class prevalence, confusion matrix, thresholds, and missed-fraud cost.
- Inspect document types, OCR quality, extracted text, language detection, and document access.
- Version reusable transformations and validate feature parity between training and serving.
- Evaluate the model using appropriate metrics and select a reviewed operating threshold.
- Create a governed embedding pipeline with versioned updates and access-aware retrieval.
Explanation
Correct Answers
A:Review class prevalence, confusion matrix, thresholds, and missed-fraud cost. This is the applicable diagnostic investigation. Its complementary step is: Evaluate the model using appropriate metrics and select a reviewed operating threshold. Together they address: Imbalanced classification requires precision, recall, and business-cost analysis beyond accuracy.
D:Evaluate the model using appropriate metrics and select a reviewed operating threshold. This is the applicable controlled engineering response. Its complementary step is: Review class prevalence, confusion matrix, thresholds, and missed-fraud cost. Together they address: Imbalanced classification requires precision, recall, and business-cost analysis beyond accuracy.
Incorrect Answers
B:Inspect document types, OCR quality, extracted text, language detection, and document access. This could be useful for another system: A records team ingests scanned PDFs for semantic search but indexes raw unreadable binary bytes as if they were meaningful text. For this situation, the necessary paired decisions are to examine (Review class prevalence, confusion matrix, thresholds, and missed-fraud cost.) and to implement (Evaluate the model using appropriate metrics and select a reviewed operating threshold.).
C:Version reusable transformations and validate feature parity between training and serving. This could be useful for another system: A production model receives categorical values in a format different from the BigQuery ML training transformations. For this situation, the necessary paired decisions are to examine (Review class prevalence, confusion matrix, thresholds, and missed-fraud cost.) and to implement (Evaluate the model using appropriate metrics and select a reviewed operating threshold.).
E:Create a governed embedding pipeline with versioned updates and access-aware retrieval. 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 (Review class prevalence, confusion matrix, thresholds, and missed-fraud cost.) and to implement (Evaluate the model using appropriate metrics and select a reviewed operating threshold.).
Question 350
A design review evaluates this situation: Researchers place thousands of raw objects in a data lake and cannot identify schemas, ownership, or classification. Which shortcut should the team MOST specifically avoid?
- Assume increasing total stored bytes proves every expected partition was delivered.
- Treat unstructured bucket prefixes as a fully governed enterprise data catalog.
- Keep appending individual records as separate immutable files and assume performance cannot degrade.
- Rename columns freely and promise consumers will infer which meanings changed.
Explanation
Correct Answer
B:Treat unstructured bucket prefixes as a fully governed enterprise data catalog. This is the unsafe shortcut directly relevant to the stated system. A better approach is: Register lake assets in Dataplex Catalog with curated metadata and governed discovery. Why: A useful data lake needs catalog metadata and lifecycle governance, not only cheap object storage.
Incorrect Answers
A:Assume increasing total stored bytes proves every expected partition was delivered. This addresses a different situation: A data lake ingestion job repeatedly misses one daily source partition yet storage dashboards show only total object count. The current scenario instead calls for the more directly applicable unsafe shortcut: Treat unstructured bucket prefixes as a fully governed enterprise data catalog. The reason is that a useful data lake needs catalog metadata and lifecycle governance, not only cheap object storage.
C:Keep appending individual records as separate immutable files and assume performance cannot degrade. This addresses a different situation: A Spark job writes millions of tiny Parquet objects, causing large listing overhead and poor query performance across the lake. The current scenario instead calls for the more directly applicable unsafe shortcut: Treat unstructured bucket prefixes as a fully governed enterprise data catalog. The reason is that a useful data lake needs catalog metadata and lifecycle governance, not only cheap object storage.
D:Rename columns freely and promise consumers will infer which meanings changed. This addresses a different situation: Multiple departments publish raw JSON to a shared lake with inconsistent field definitions that break downstream reusable tables. The current scenario instead calls for the more directly applicable unsafe shortcut: Treat unstructured bucket prefixes as a fully governed enterprise data catalog. The reason is that a useful data lake needs catalog metadata and lifecycle governance, not only cheap object storage.