Google Professional Data Engineer Practice Test 27
Question 260
The data engineering team must correct this issue: A media company keeps infrequently accessed raw video assets in standard storage for years and has no retention or retrieval policy. Which controlled engineering action is MOST appropriate?
- Apply reviewed Cloud Storage lifecycle policies with an approved cold-tier or deletion strategy.
- Configure supported PITR and conduct a rehearsal into an isolated recovery instance.
- Use a suitable Cloud SQL edition and HA configuration with controlled migrations.
- Partition by the relevant date field and cluster on useful high-selectivity columns where appropriate.
Explanation
Correct Answer
A:Apply reviewed Cloud Storage lifecycle policies with an approved cold-tier or deletion strategy. This addresses the specific problem while respecting business and technical constraints. Validate it by checking: An old object transitions only as allowed and remains retrievable when legally required. Object storage class and lifecycle choices should reflect access frequency, retrieval cost, and legal retention.
Incorrect Answers
B:Configure supported PITR and conduct a rehearsal into an isolated recovery instance. This addresses a different situation: A PostgreSQL operational service needs to restore state from immediately before a faulty data migration, not merely from the last weekly export. The current scenario instead calls for the more directly applicable engineering action: Apply reviewed Cloud Storage lifecycle policies with an approved cold-tier or deletion strategy. The reason is that object storage class and lifecycle choices should reflect access frequency, retrieval cost, and legal retention.
C:Use a suitable Cloud SQL edition and HA configuration with controlled migrations. This addresses a different situation: A small business runs a conventional PostgreSQL order service and needs managed backups and routine high availability without massive global horizontal write scale. The current scenario instead calls for the more directly applicable engineering action: Apply reviewed Cloud Storage lifecycle policies with an approved cold-tier or deletion strategy. The reason is that object storage class and lifecycle choices should reflect access frequency, retrieval cost, and legal retention.
D:Partition by the relevant date field and cluster on useful high-selectivity columns where appropriate. This addresses a different situation: A warehouse stores years of events and most reports filter by event date and customer segment, but all queries scan the full table. The current scenario instead calls for the more directly applicable engineering action: Apply reviewed Cloud Storage lifecycle policies with an approved cold-tier or deletion strategy. The reason is that object storage class and lifecycle choices should reflect access frequency, retrieval cost, and legal retention.
Question 261
The data engineering team must correct this issue: An order service needs multi-row transactional correctness, yet engineers propose independent uncoordinated object writes as the system of record. Which controlled engineering action is MOST appropriate?
- Choose a supported transactional database design and execute related mutations in governed transactions.
- Use supported Dataflow recovery and replay procedures with independently verified sink idempotency.
- Declare required upstream dependencies and freshness checks before downstream materialization.
- Implement an approved multi-location or recoverable regional design with tested failover and data reconciliation.
Explanation
Correct Answer
A:Choose a supported transactional database design and execute related mutations in governed transactions. This addresses the specific problem while respecting business and technical constraints. Validate it by checking: A deliberately interrupted order update cannot leave mutually inconsistent committed rows. Transactional workloads require storage semantics that match atomicity and consistency requirements.
Incorrect Answers
B:Use supported Dataflow recovery and replay procedures with independently verified sink idempotency. 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 engineering action: Choose a supported transactional database design and execute related mutations in governed transactions. The reason is that transactional workloads require storage semantics that match atomicity and consistency requirements.
C:Declare required upstream dependencies and freshness checks before downstream materialization. This addresses a different situation: A Dataform pipeline materializes monthly revenue before its upstream exchange-rate table refresh completes. The current scenario instead calls for the more directly applicable engineering action: Choose a supported transactional database design and execute related mutations in governed transactions. The reason is that transactional workloads require storage semantics that match atomicity and consistency requirements.
D:Implement an approved multi-location or recoverable regional design with tested failover and data reconciliation. This addresses a different situation: A regional processing failure stops daily regulatory datasets because all staging, computation, and recovery copies reside in one failure domain. The current scenario instead calls for the more directly applicable engineering action: Choose a supported transactional database design and execute related mutations in governed transactions. The reason is that transactional workloads require storage semantics that match atomicity and consistency requirements.
Question 262
A design review evaluates this situation: A Dataflow group-by-key stage slows because almost all events share one constant grouping value. Which shortcut should the team MOST specifically avoid?
- Group events only by the worker machine's current clock and ignore event timestamps.
- Leave a full cluster running continuously because input files are stored permanently.
- Discard all events whose enrichment lookup is momentarily unavailable.
- Double worker count indefinitely while leaving all records under one hot key.
Explanation
Correct Answer
D:Double worker count indefinitely while leaving all records under one hot key. This is the unsafe shortcut directly relevant to the stated system. A better approach is: Redesign the aggregation key or introduce valid fan-out patterns where supported. Why: Skewed keys can serialize distributed work and degrade parallel pipeline throughput.
Incorrect Answers
A:Group events only by the worker machine's current clock and ignore event timestamps. This addresses a different situation: A fraud model groups purchases into ten-minute windows, but late device clocks place events into the wrong billing period. The current scenario instead calls for the more directly applicable unsafe shortcut: Double worker count indefinitely while leaving all records under one hot key. The reason is that skewed keys can serialize distributed work and degrade parallel pipeline throughput.
B:Leave a full cluster running continuously because input files are stored permanently. 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 unsafe shortcut: Double worker count indefinitely while leaving all records under one hot key. The reason is that skewed keys can serialize distributed work and degrade parallel pipeline throughput.
C:Discard all events whose enrichment lookup is momentarily unavailable. This addresses a different situation: Device readings arrive every second but the related factory equipment registration data changes hourly, producing joins with missing references. The current scenario instead calls for the more directly applicable unsafe shortcut: Double worker count indefinitely while leaving all records under one hot key. The reason is that skewed keys can serialize distributed work and degrade parallel pipeline throughput.
Question 263
Before modifying the data platform, the team observes: A PostgreSQL operational service needs to restore state from immediately before a faulty data migration, not merely from the last weekly export. Which evidence should the engineer examine FIRST?
- Inspect filter selectivity, partitions scanned, clustering cardinality, and query statistics.
- Review object layout, table format, supported engines, and access-control model.
- Check engine compatibility, transaction volume, connection patterns, HA needs, and backups.
- Inspect Cloud SQL backup policy, transaction logs, recovery window, and RPO/RTO.
Explanation
Correct Answer
D:Inspect Cloud SQL backup policy, transaction logs, recovery window, and RPO/RTO. This evidence directly tests the uncertain part of the described system. Point-in-time recovery depends on supported continuous backups/log retention and tested restoration. A controlled response is: Configure supported PITR and conduct a rehearsal into an isolated recovery instance.
Incorrect Answers
A:Inspect filter selectivity, partitions scanned, clustering cardinality, and query statistics. This addresses a different situation: A warehouse stores years of events and most reports filter by event date and customer segment, but all queries scan the full table. The current scenario instead calls for the more directly applicable investigation: Inspect Cloud SQL backup policy, transaction logs, recovery window, and RPO/RTO. The reason is that point-in-time recovery depends on supported continuous backups/log retention and tested restoration.
B:Review object layout, table format, supported engines, and access-control model. This addresses a different situation: A lakehouse platform keeps Parquet in Cloud Storage but wants managed governance across BigQuery and compatible external engines. The current scenario instead calls for the more directly applicable investigation: Inspect Cloud SQL backup policy, transaction logs, recovery window, and RPO/RTO. The reason is that point-in-time recovery depends on supported continuous backups/log retention and tested restoration.
C:Check engine compatibility, transaction volume, connection patterns, HA needs, and backups. This addresses a different situation: A small business runs a conventional PostgreSQL order service and needs managed backups and routine high availability without massive global horizontal write scale. The current scenario instead calls for the more directly applicable investigation: Inspect Cloud SQL backup policy, transaction logs, recovery window, and RPO/RTO. The reason is that point-in-time recovery depends on supported continuous backups/log retention and tested restoration.
Question 264
A Google Cloud data engineer is addressing: A finance warehouse needs recoverable reporting after regional disruption but keeps its only critical dataset in one region. Which TWO complementary actions should the team take? Select TWO answers.
- Inspect dataset locations, backup/copy capabilities, recovery targets, and permitted residency.
- Route writes through the supported transactional primary or managed failover endpoint with retry handling.
- Develop a tested regional recovery workflow with replay controls and data reconciliation.
- Inspect affected partitions, ingestion manifests, validation history, and recovery sources.
- Design and test a compatible cross-location recovery approach consistent with regulation.
Explanation
Correct Answers
A:Inspect dataset locations, backup/copy capabilities, recovery targets, and permitted residency. This is the applicable diagnostic investigation. Its complementary step is: Design and test a compatible cross-location recovery approach consistent with regulation. Together they address: Analytical recovery requires independently retained copies and known restore procedures that meet policy.
E:Design and test a compatible cross-location recovery approach consistent with regulation. This is the applicable controlled engineering response. Its complementary step is: Inspect dataset locations, backup/copy capabilities, recovery targets, and permitted residency. Together they address: Analytical recovery requires independently retained copies and known restore procedures that meet policy.
Incorrect Answers
B:Route writes through the supported transactional primary or managed failover endpoint with retry handling. This could be useful for another system: An application routes financial writes to a stale read replica after primary failure, returning success before records are durably committed. For this situation, the necessary paired decisions are to examine (Inspect dataset locations, backup/copy capabilities, recovery targets, and permitted residency.) and to implement (Design and test a compatible cross-location recovery approach consistent with regulation.).
C:Develop a tested regional recovery workflow with replay controls and data reconciliation. This could be useful for another system: A critical Pub/Sub-to-warehouse flow has a secondary-region deployment template but no retained state, failover routing, or test exercise. For this situation, the necessary paired decisions are to examine (Inspect dataset locations, backup/copy capabilities, recovery targets, and permitted residency.) and to implement (Design and test a compatible cross-location recovery approach consistent with regulation.).
D:Inspect affected partitions, ingestion manifests, validation history, and recovery sources. This could be useful for another system: An upstream vendor accidentally publishes a corrupted schema version and downstream totals become wrong before anyone notices. For this situation, the necessary paired decisions are to examine (Inspect dataset locations, backup/copy capabilities, recovery targets, and permitted residency.) and to implement (Design and test a compatible cross-location recovery approach consistent with regulation.).
Question 265
Before modifying the data platform, the team observes: A daily fact table receives corrections, but each load recomputes every historical year and causes excessive query cost. Which evidence should the engineer examine FIRST?
- Inspect change-watermarks, partition dates, correction frequency, and merge costs.
- Inspect query patterns, expected item cardinality, update frequency, and aggregation semantics.
- Review source change history, effective timestamps, invoice event times, and model grain.
- Inspect frequent aggregations, dashboard latency, update frequency, and BigQuery feature support.
Explanation
Correct Answer
A:Inspect change-watermarks, partition dates, correction frequency, and merge costs. This evidence directly tests the uncertain part of the described system. Incremental transformations should process only changed partitions where correctness permits. A controlled response is: Build an incremental partition-aware load with validated late-change reconciliation.
Incorrect Answers
B:Inspect query patterns, expected item cardinality, update frequency, and aggregation semantics. 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 investigation: Inspect change-watermarks, partition dates, correction frequency, and merge costs. The reason is that incremental transformations should process only changed partitions where correctness permits.
C:Review source change history, effective timestamps, invoice event times, and model grain. 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 investigation: Inspect change-watermarks, partition dates, correction frequency, and merge costs. The reason is that incremental transformations should process only changed partitions where correctness permits.
D:Inspect frequent aggregations, dashboard latency, update frequency, and BigQuery feature support. This addresses a different situation: A popular dashboard repeatedly computes the same large daily summary with strict latency goals, while raw transactional records remain necessary for detail drill-down. The current scenario instead calls for the more directly applicable investigation: Inspect change-watermarks, partition dates, correction frequency, and merge costs. The reason is that incremental transformations should process only changed partitions where correctness permits.
Question 266
The data engineering team must correct this issue: Developers change Dataflow transform logic directly in production with no version tags or regression tests. Which controlled engineering action is MOST appropriate?
- Publish a tested parameterized template with approved environment configuration.
- Add supported readiness checks and explicit directed dependencies to the Composer workflow.
- Add a reviewed CI pipeline with unit/integration tests and controlled Dataflow template promotion.
- Implement a governed backfill workflow with bounded concurrent writes and reconciliation.
Explanation
Correct Answer
C:Add a reviewed CI pipeline with unit/integration tests and controlled Dataflow template promotion. This addresses the specific problem while respecting business and technical constraints. Validate it by checking: A deliberately incompatible schema change is blocked before a production job update. Data pipeline CI/CD should validate schema, code, and deployment before production promotion.
Incorrect Answers
A:Publish a tested parameterized template with approved environment configuration. This addresses a different situation: The same Dataflow template should run in staging and production but contains hardcoded staging bucket names and service-account references. The current scenario instead calls for the more directly applicable engineering action: Add a reviewed CI pipeline with unit/integration tests and controlled Dataflow template promotion. The reason is that data pipeline CI/CD should validate schema, code, and deployment before production promotion.
B:Add supported readiness checks and explicit directed dependencies to the Composer workflow. This addresses a different situation: An Airflow DAG launches a billing aggregation before its source partition arrives, producing empty reports that appear successful. The current scenario instead calls for the more directly applicable engineering action: Add a reviewed CI pipeline with unit/integration tests and controlled Dataflow template promotion. The reason is that data pipeline CI/CD should validate schema, code, and deployment before production promotion.
D: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: Add a reviewed CI pipeline with unit/integration tests and controlled Dataflow template promotion. The reason is that data pipeline CI/CD should validate schema, code, and deployment before production promotion.
Question 267
The data engineering team must correct this issue: An internal ERP system sends sensitive database extracts to Google Cloud but security rules prohibit unrestricted internet endpoints. Which controlled engineering action is MOST appropriate?
- Adopt versioned landing paths and idempotent manifest processing before transformation.
- Configure appropriate message retention or raw event archival for replay and recovery.
- Design an approved private or restricted connection with encrypted transfer and scoped workload identity.
- Use Pub/Sub and an appropriately configured Dataflow stream with an approved low-latency sink.
Explanation
Correct Answer
C:Design an approved private or restricted connection with encrypted transfer and scoped workload identity. This addresses the specific problem while respecting business and technical constraints. Validate it by checking: A source extract reaches the authorized destination without exposing an unauthenticated public endpoint. Ingestion networking and encryption must align with connectivity and trust boundaries.
Incorrect Answers
A: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: Design an approved private or restricted connection with encrypted transfer and scoped workload identity. The reason is that ingestion networking and encryption must align with connectivity and trust boundaries.
B: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: Design an approved private or restricted connection with encrypted transfer and scoped workload identity. The reason is that ingestion networking and encryption must align with connectivity and trust boundaries.
D:Use Pub/Sub and an appropriately configured Dataflow stream with an approved low-latency sink. 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 engineering action: Design an approved private or restricted connection with encrypted transfer and scoped workload identity. The reason is that ingestion networking and encryption must align with connectivity and trust boundaries.
Question 268
Before modifying the data platform, the team observes: Customer support event feeds contain phone numbers and account identifiers, but most analysts require only behavioral aggregates. Which evidence should the engineer examine FIRST?
- Review dataset and table encryption settings, Cloud KMS key permissions, key location, and rotation policy.
- Check data classifications, policy tags, user groups, dataset roles, and sample SELECT permissions.
- Inspect Dataflow worker identity, source bucket policies, destination dataset grants, and credential handling.
- Inventory PII fields, consumer roles, retention policies, and approved de-identification requirements.
Explanation
Correct Answer
D:Inventory PII fields, consumer roles, retention policies, and approved de-identification requirements. This evidence directly tests the uncertain part of the described system. Minimizing personal data exposure reduces risk while preserving necessary analytical utility. A controlled response is: De-identify or tokenize sensitive columns upstream and publish a limited-use analytical dataset.
Incorrect Answers
A:Review dataset and table encryption settings, Cloud KMS key permissions, key location, and rotation policy. This addresses a different situation: A regulated finance team requires customer-managed keys for sensitive BigQuery tables and documented key revocation procedures. The current scenario instead calls for the more directly applicable investigation: Inventory PII fields, consumer roles, retention policies, and approved de-identification requirements. The reason is that minimizing personal data exposure reduces risk while preserving necessary analytical utility.
B:Check data classifications, policy tags, user groups, dataset roles, and sample SELECT permissions. This addresses a different situation: Analysts may inspect product transactions but only a small fraud group may see a sensitive risk score in the same table. The current scenario instead calls for the more directly applicable investigation: Inventory PII fields, consumer roles, retention policies, and approved de-identification requirements. The reason is that minimizing personal data exposure reduces risk while preserving necessary analytical utility.
C:Inspect Dataflow worker identity, source bucket policies, destination dataset grants, and credential handling. This addresses a different situation: A Dataflow job in a processing project reads raw data from an ingestion project but uses a broad human administrator credential. The current scenario instead calls for the more directly applicable investigation: Inventory PII fields, consumer roles, retention policies, and approved de-identification requirements. The reason is that minimizing personal data exposure reduces risk while preserving necessary analytical utility.
Question 269
A Google Cloud architecture review finds: A fraud model groups purchases into ten-minute windows, but late device clocks place events into the wrong billing period. Which principle BEST explains the underlying data-engineering risk?
- Event-time processing requires explicit windowing, watermarks, allowed lateness, and correction behavior.
- Integration choice should preserve existing event semantics while decoupling cloud consumers.
- Skewed keys can serialize distributed work and degrade parallel pipeline throughput.
- Streaming schemas need compatibility rules and controlled unknown-field behavior.
Explanation
Correct Answer
A:Event-time processing requires explicit windowing, watermarks, allowed lateness, and correction behavior. This principle identifies the relevant workload or governance requirement. The engineer should first examine: Review event timestamps, watermark progress, late-data distribution, and aggregation triggers. A focused corrective action is: Configure Apache Beam windows and late-data handling appropriate to the report contract.
Incorrect Answers
B:Integration choice should preserve existing event semantics while decoupling cloud consumers. 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 principle: Event-time processing requires explicit windowing, watermarks, allowed lateness, and correction behavior. The reason is that event-time processing requires explicit windowing, watermarks, allowed lateness, and correction behavior.
C:Skewed keys can serialize distributed work and degrade parallel pipeline throughput. 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 principle: Event-time processing requires explicit windowing, watermarks, allowed lateness, and correction behavior. The reason is that event-time processing requires explicit windowing, watermarks, allowed lateness, and correction behavior.
D:Streaming schemas need compatibility rules and controlled unknown-field behavior. 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 principle: Event-time processing requires explicit windowing, watermarks, allowed lateness, and correction behavior. The reason is that event-time processing requires explicit windowing, watermarks, allowed lateness, and correction behavior.
Question 270
A design review evaluates this situation: A same-day executive dashboard competes with a large nonurgent nightly historical rebuild. Which shortcut should the team MOST specifically avoid?
- Treat optional experimentation as higher priority than every active financial obligation.
- Assume flat capacity always reduces cost without comparing sustained usage or limitations.
- Allow unbounded exploratory queries to preempt all production reservations.
- Classify every long backfill as interactive critical even when it has no urgent deadline.
Explanation
Correct Answer
D:Classify every long backfill as interactive critical even when it has no urgent deadline. This is the unsafe shortcut directly relevant to the stated system. A better approach is: Use appropriate interactive and batch workload controls with guaranteed critical capacity. Why: Job priority and capacity policies should reflect latency sensitivity and business importance.
Incorrect Answers
A:Treat optional experimentation as higher priority than every active financial obligation. This addresses a different situation: A payment streaming system is operationally critical, but monthly experimentation triggers heavy resource contention and delayed settlement events. The current scenario instead calls for the more directly applicable unsafe shortcut: Classify every long backfill as interactive critical even when it has no urgent deadline. The reason is that job priority and capacity policies should reflect latency sensitivity and business importance.
B:Assume flat capacity always reduces cost without comparing sustained usage or limitations. This addresses a different situation: A platform has steady high-volume SQL demand but is paying unpredictable per-query cost while finance requires capacity budgets. The current scenario instead calls for the more directly applicable unsafe shortcut: Classify every long backfill as interactive critical even when it has no urgent deadline. The reason is that job priority and capacity policies should reflect latency sensitivity and business importance.
C:Allow unbounded exploratory queries to preempt all production reservations. 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 unsafe shortcut: Classify every long backfill as interactive critical even when it has no urgent deadline. The reason is that job priority and capacity policies should reflect latency sensitivity and business importance.