Google Professional Data Engineer Practice Test 14
Question 130
A design review evaluates this situation: An analytics query sorts a multi-terabyte table globally before returning 20 leaderboard entries, exhausting resources. Which shortcut should the team MOST specifically avoid?
- Promise all materialized views deliver strictly synchronous updates for every unsupported SQL feature.
- Use LIMIT before grouping to compute a misleading leaderboard from arbitrary input rows.
- Give dashboard filters write privileges so user text can alter underlying tables.
- Hide sensitive chart columns visually and call that sufficient warehouse access control.
Explanation
Correct Answer
B:Use LIMIT before grouping to compute a misleading leaderboard from arbitrary input rows. This is the unsafe shortcut directly relevant to the stated system. A better approach is: Restructure the aggregation and limit after appropriate grouping with efficient filtering. Why: Analytical query plans should reduce large intermediates and sort only necessary data.
Incorrect Answers
A:Promise all materialized views deliver strictly synchronous updates for every unsupported SQL feature. This addresses a different situation: A reporting team creates a materialized view but expects it to instantaneously reflect every base-table update under all query patterns. The current scenario instead calls for the more directly applicable unsafe shortcut: Use LIMIT before grouping to compute a misleading leaderboard from arbitrary input rows. The reason is that analytical query plans should reduce large intermediates and sort only necessary data.
C:Give dashboard filters write privileges so user text can alter underlying tables. This addresses a different situation: A dashboard generates dynamic SQL by concatenating raw user text into filters and risks malformed or unsafe queries. The current scenario instead calls for the more directly applicable unsafe shortcut: Use LIMIT before grouping to compute a misleading leaderboard from arbitrary input rows. The reason is that analytical query plans should reduce large intermediates and sort only necessary data.
D:Hide sensitive chart columns visually and call that sufficient warehouse access control. This addresses a different situation: A marketing dashboard in Looker Studio displays performance summaries but the configured data source grants unrestricted access to restricted BigQuery customer fields. The current scenario instead calls for the more directly applicable unsafe shortcut: Use LIMIT before grouping to compute a misleading leaderboard from arbitrary input rows. The reason is that analytical query plans should reduce large intermediates and sort only necessary data.
Question 131
After applying the change, the team re-examines this condition: A yearly backfill invokes all daily dependent tasks concurrently, while downstream aggregation assumes every day is already complete. Which result BEST verifies the improvement?
- An annual report is published only after all prerequisite historical partitions reconcile.
- Two runs at the same approved revision apply expected transformations without unreviewed edits.
- Restarting a failed DAG does not double-charge a test invoice.
- A temporary 503 recovers and the export completes once without repeating committed actions.
Explanation
Correct Answer
A:An annual report is published only after all prerequisite historical partitions reconcile. This measures the intended corrected behavior rather than only confirming a setting. Implemented action: Create a parameterized backfill DAG with ordered readiness checks and bounded parallelism. Backfill workflows need dependency awareness and capacity controls.
Incorrect Answers
B:Two runs at the same approved revision apply expected transformations without unreviewed edits. This addresses a different situation: A production ELT workflow pulls arbitrary local workspace changes without approvals, creating nondeterministic table definitions. The current scenario instead calls for the more directly applicable verification result: An annual report is published only after all prerequisite historical partitions reconcile. The reason is that backfill workflows need dependency awareness and capacity controls.
C:Restarting a failed DAG does not double-charge a test invoice. This addresses a different situation: An Airflow DAG reruns after scheduler recovery and reissues the same external billing update twice. The current scenario instead calls for the more directly applicable verification result: An annual report is published only after all prerequisite historical partitions reconcile. The reason is that backfill workflows need dependency awareness and capacity controls.
D:A temporary 503 recovers and the export completes once without repeating committed actions. This addresses a different situation: A managed API intermittently returns 503, causing a multi-step data export workflow to fail permanently without preserving state. The current scenario instead calls for the more directly applicable verification result: An annual report is published only after all prerequisite historical partitions reconcile. The reason is that backfill workflows need dependency awareness and capacity controls.
Question 132
A design review evaluates this situation: A compliance team cannot determine which identity exported a restricted BigQuery customer table last week. Which shortcut should the team MOST specifically avoid?
- Disable data access logs to save money and depend on users describing their own actions.
- Assume a global cloud provider automatically keeps every transfer within the customer's country.
- Give experimental notebooks write access to every production table by default.
- Copy unrestricted raw customer identifiers into every reporting mart for convenience.
Explanation
Correct Answer
A:Disable data access logs to save money and depend on users describing their own actions. This is the unsafe shortcut directly relevant to the stated system. A better approach is: Enable and retain required audit events with protected sinks and monitored access policies. Why: Audit logging and appropriate retention provide traceability of privileged data access and exports.
Incorrect Answers
B:Assume a global cloud provider automatically keeps every transfer within the customer's country. This addresses a different situation: A European customer contract restricts processing and storage to approved locations, while engineers intend to replicate datasets to another continent. The current scenario instead calls for the more directly applicable unsafe shortcut: Disable data access logs to save money and depend on users describing their own actions. The reason is that audit logging and appropriate retention provide traceability of privileged data access and exports.
C:Give experimental notebooks write access to every production table by default. This addresses a different situation: Developers test destructive transformations against the same production dataset used for regulatory reporting. The current scenario instead calls for the more directly applicable unsafe shortcut: Disable data access logs to save money and depend on users describing their own actions. The reason is that audit logging and appropriate retention provide traceability of privileged data access and exports.
D:Copy unrestricted raw customer identifiers into every reporting mart for convenience. This addresses a different situation: Customer support event feeds contain phone numbers and account identifiers, but most analysts require only behavioral aggregates. The current scenario instead calls for the more directly applicable unsafe shortcut: Disable data access logs to save money and depend on users describing their own actions. The reason is that audit logging and appropriate retention provide traceability of privileged data access and exports.
Question 133
Before modifying the data platform, the team observes: A pipeline deployment hardcodes one project ID and dataset location into every query, blocking deployment into another approved region. Which evidence should the engineer examine FIRST?
- Inspect landing locations, transformation stages, table permissions, and traceability of corrections.
- Review schema versions, producer changes, consumer dependencies, and failed-message records.
- Review embedded project identifiers, regional service compatibility, and configuration files.
- Inspect forecast data volume, query patterns, ingestion rates, retention, and service limits.
Explanation
Correct Answer
C:Review embedded project identifiers, regional service compatibility, and configuration files. This evidence directly tests the uncertain part of the described system. Deployment portability requires parameterized environment-specific resources and validated locations. A controlled response is: Parameterize destination projects and locations through controlled environment configuration.
Incorrect Answers
A:Inspect landing locations, transformation stages, table permissions, and traceability of corrections. 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 investigation: Review embedded project identifiers, regional service compatibility, and configuration files. The reason is that deployment portability requires parameterized environment-specific resources and validated locations.
B:Review schema versions, producer changes, consumer dependencies, and failed-message records. This addresses a different situation: Three applications produce events into a common stream, and one deploys a breaking field rename without notifying downstream consumers. The current scenario instead calls for the more directly applicable investigation: Review embedded project identifiers, regional service compatibility, and configuration files. The reason is that deployment portability requires parameterized environment-specific resources and validated locations.
D:Inspect forecast data volume, query patterns, ingestion rates, retention, and service limits. This addresses a different situation: A pilot warehouse handles thousands of daily events but must support hundreds of millions without rewriting every consuming dashboard. The current scenario instead calls for the more directly applicable investigation: Review embedded project identifiers, regional service compatibility, and configuration files. The reason is that deployment portability requires parameterized environment-specific resources and validated locations.
Question 134
A Google Cloud data engineer is addressing: A PostgreSQL operational service needs to restore state from immediately before a faulty data migration, not merely from the last weekly export. Which TWO complementary actions should the team take? Select TWO answers.
- Inspect Cloud SQL backup policy, transaction logs, recovery window, and RPO/RTO.
- Configure supported PITR and conduct a rehearsal into an isolated recovery instance.
- Benchmark a compatible AlloyDB deployment with appropriate read pools and operational design.
- Review object layout, table format, supported engines, and access-control model.
- Review legal retention periods, bucket settings, object holds, and administrator rights.
Explanation
Correct Answers
A:Inspect Cloud SQL backup policy, transaction logs, recovery window, and RPO/RTO. This is the applicable diagnostic investigation. Its complementary step is: Configure supported PITR and conduct a rehearsal into an isolated recovery instance. Together they address: Point-in-time recovery depends on supported continuous backups/log retention and tested restoration.
B:Configure supported PITR and conduct a rehearsal into an isolated recovery instance. This is the applicable controlled engineering response. Its complementary step is: Inspect Cloud SQL backup policy, transaction logs, recovery window, and RPO/RTO. Together they address: Point-in-time recovery depends on supported continuous backups/log retention and tested restoration.
Incorrect Answers
C:Benchmark a compatible AlloyDB deployment with appropriate read pools and operational design. This could be useful for another system: A PostgreSQL-compatible application has intensive operational transactions plus complex analytical queries and wants compatible managed performance options. For this situation, the necessary paired decisions are to examine (Inspect Cloud SQL backup policy, transaction logs, recovery window, and RPO/RTO.) and to implement (Configure supported PITR and conduct a rehearsal into an isolated recovery instance.).
D:Review object layout, table format, supported engines, and access-control model. This could be useful for another system: A lakehouse platform keeps Parquet in Cloud Storage but wants managed governance across BigQuery and compatible external engines. For this situation, the necessary paired decisions are to examine (Inspect Cloud SQL backup policy, transaction logs, recovery window, and RPO/RTO.) and to implement (Configure supported PITR and conduct a rehearsal into an isolated recovery instance.).
E:Review legal retention periods, bucket settings, object holds, and administrator rights. This could be useful for another system: A legal investigation requires evidence objects to remain unchanged for a prescribed duration, while administrators can currently delete them. For this situation, the necessary paired decisions are to examine (Inspect Cloud SQL backup policy, transaction logs, recovery window, and RPO/RTO.) and to implement (Configure supported PITR and conduct a rehearsal into an isolated recovery instance.).
Question 135
The data engineering team must correct this issue: A critical Pub/Sub-to-warehouse flow has a secondary-region deployment template but no retained state, failover routing, or test exercise. Which controlled engineering action is MOST appropriate?
- Choose an appropriate BigQuery Editions reservation arrangement and workload assignments.
- 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.
- Configure supported regional high availability and test application reconnection.
Explanation
Correct Answer
C:Develop a tested regional recovery workflow with replay controls and data reconciliation. This addresses the specific problem while respecting business and technical constraints. Validate it by checking: A regional failover exercise meets RPO/RTO and produces no material missing or duplicated transactions. Disaster-recovery readiness requires explicit source replay, state reconciliation, and executable failover runbooks.
Incorrect Answers
A:Choose an appropriate BigQuery Editions reservation arrangement and workload assignments. 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 engineering action: Develop a tested regional recovery workflow with replay controls and data reconciliation. The reason is that disaster-recovery readiness requires explicit source replay, state reconciliation, and executable failover runbooks.
B: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: Develop a tested regional recovery workflow with replay controls and data reconciliation. The reason is that disaster-recovery readiness requires explicit source replay, state reconciliation, and executable failover runbooks.
D: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: Develop a tested regional recovery workflow with replay controls and data reconciliation. The reason is that disaster-recovery readiness requires explicit source replay, state reconciliation, and executable failover runbooks.
Question 136
A Google Cloud data engineer is addressing: A Dataproc Spark batch shuffles terabytes into a handful of very large partitions and regularly runs out of memory. Which TWO complementary actions should the team take? Select TWO answers.
- Review cluster utilization, job run time, startup overhead, and storage dependencies.
- Tune adaptive execution and partitions or repartition skewed keys according to the workload.
- Inspect Spark UI shuffle metrics, skew, executor memory, and partition configuration.
- Compare connector support, transformations, secret storage, and execution SLAs.
- Examine sink contract, retry mechanics, transactional support, and event identifiers.
Explanation
Correct Answers
B:Tune adaptive execution and partitions or repartition skewed keys according to the workload. This is the applicable controlled engineering response. Its complementary step is: Inspect Spark UI shuffle metrics, skew, executor memory, and partition configuration. Together they address: Distributed batch jobs need partitioning that matches data volume and available executor resources.
C:Inspect Spark UI shuffle metrics, skew, executor memory, and partition configuration. This is the applicable diagnostic investigation. Its complementary step is: Tune adaptive execution and partitions or repartition skewed keys according to the workload. Together they address: Distributed batch jobs need partitioning that matches data volume and available executor resources.
Incorrect Answers
A:Review cluster utilization, job run time, startup overhead, and storage dependencies. This could be useful for another system: A once-weekly Spark transformation uses a permanently running Dataproc cluster that sits idle most of the week. For this situation, the necessary paired decisions are to examine (Inspect Spark UI shuffle metrics, skew, executor memory, and partition configuration.) and to implement (Tune adaptive execution and partitions or repartition skewed keys according to the workload.).
D:Compare connector support, transformations, secret storage, and execution SLAs. This could be useful for another system: A team has several supported relational sources and needs standard cleansing workflows but maintains dozens of brittle custom extraction scripts. For this situation, the necessary paired decisions are to examine (Inspect Spark UI shuffle metrics, skew, executor memory, and partition configuration.) and to implement (Tune adaptive execution and partitions or repartition skewed keys according to the workload.).
E:Examine sink contract, retry mechanics, transactional support, and event identifiers. This could be useful for another system: An engineer claims an exactly-once Dataflow pipeline makes arbitrary external API side effects impossible to duplicate. For this situation, the necessary paired decisions are to examine (Inspect Spark UI shuffle metrics, skew, executor memory, and partition configuration.) and to implement (Tune adaptive execution and partitions or repartition skewed keys according to the workload.).
Question 137
A Google Cloud architecture review finds: A payment streaming system is operationally critical, but monthly experimentation triggers heavy resource contention and delayed settlement events. Which principle BEST explains the underlying data-engineering risk?
- 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.
- Business-critical data processing should have planned resource isolation and failover controls.
- Capacity pricing and reservations should be evaluated against measured utilization and service commitments.
Explanation
Correct Answer
C:Business-critical data processing should have planned resource isolation and failover controls. This principle identifies the relevant workload or governance requirement. The engineer should first examine: Inspect queue lag, concurrency controls, reservation usage, and critical event SLAs. A focused corrective action is: Protect streaming settlement capacity and schedule noncritical experiments appropriately.
Incorrect Answers
A: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: Business-critical data processing should have planned resource isolation and failover controls. The reason is that business-critical data processing should have planned resource isolation and failover controls.
B: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: Business-critical data processing should have planned resource isolation and failover controls. The reason is that business-critical data processing should have planned resource isolation and failover controls.
D:Capacity pricing and reservations should be evaluated against measured utilization and service commitments. 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 principle: Business-critical data processing should have planned resource isolation and failover controls. The reason is that business-critical data processing should have planned resource isolation and failover controls.
Question 138
Before modifying the data platform, the team observes: A Dataflow JavaScript or Python user-defined transform catches every exception and returns an empty record, hiding thousands of failed rows. Which evidence should the engineer examine FIRST?
- Review UDF exceptions, input samples, metrics, and dead-letter records.
- Inspect ticket contents, model input logs, privacy policies, and enrichment accuracy.
- Examine sink contract, retry mechanics, transactional support, and event identifiers.
- Review schema versions, parser settings, failed-message samples, and consumer expectations.
Explanation
Correct Answer
A:Review UDF exceptions, input samples, metrics, and dead-letter records. This evidence directly tests the uncertain part of the described system. Transformation failures require observable error paths and defined quality thresholds. A controlled response is: Add structured error outputs and fail or quarantine according to the data contract.
Incorrect Answers
B:Inspect ticket contents, model input logs, privacy policies, and enrichment accuracy. This addresses a different situation: A content pipeline sends customer free-text support tickets to a generative model for categorization without excluding sensitive identifiers. The current scenario instead calls for the more directly applicable investigation: Review UDF exceptions, input samples, metrics, and dead-letter records. The reason is that transformation failures require observable error paths and defined quality thresholds.
C:Examine sink contract, retry mechanics, transactional support, and event identifiers. This addresses a different situation: An engineer claims an exactly-once Dataflow pipeline makes arbitrary external API side effects impossible to duplicate. The current scenario instead calls for the more directly applicable investigation: Review UDF exceptions, input samples, metrics, and dead-letter records. The reason is that transformation failures require observable error paths and defined quality thresholds.
D:Review schema versions, parser settings, failed-message samples, and consumer expectations. 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 investigation: Review UDF exceptions, input samples, metrics, and dead-letter records. The reason is that transformation failures require observable error paths and defined quality thresholds.
Question 139
After applying the change, the team re-examines this condition: The same Dataflow template should run in staging and production but contains hardcoded staging bucket names and service-account references. Which result BEST verifies the improvement?
- A deliberately incompatible schema change is blocked before a production job update.
- One immutable template version runs correctly in both approved environments with separate data.
- A forced timeout results in one effective invoice export despite multiple attempts.
- An experimental model cannot overwrite certified datasets without an approved promotion.
Explanation
Correct Answer
B:One immutable template version runs correctly in both approved environments with separate data. This measures the intended corrected behavior rather than only confirming a setting. Implemented action: Publish a tested parameterized template with approved environment configuration. Reusable deployment artifacts require versioned code plus environment-specific parameterization.
Incorrect Answers
A:A deliberately incompatible schema change is blocked before a production job update. This addresses a different situation: Developers change Dataflow transform logic directly in production with no version tags or regression tests. The current scenario instead calls for the more directly applicable verification result: One immutable template version runs correctly in both approved environments with separate data. The reason is that reusable deployment artifacts require versioned code plus environment-specific parameterization.
C:A forced timeout results in one effective invoice export despite multiple attempts. This addresses a different situation: A pipeline triggers an invoice-export API and Airflow retries the task after a timeout, sending the same invoice twice. The current scenario instead calls for the more directly applicable verification result: One immutable template version runs correctly in both approved environments with separate data. The reason is that reusable deployment artifacts require versioned code plus environment-specific parameterization.
D:An experimental model cannot overwrite certified datasets without an approved promotion. This addresses a different situation: A team builds new SQL models in a development workspace but schedules them against production datasets using the same credentials. The current scenario instead calls for the more directly applicable verification result: One immutable template version runs correctly in both approved environments with separate data. The reason is that reusable deployment artifacts require versioned code plus environment-specific parameterization.
Question 140
A combined diagnosis-and-remediation review examines: A large Spark cluster remains at peak worker count during long idle stages because autoscaling is disabled. Which investigation followed by action BEST resolves the concern?
- Review object access frequency, retention, retrieval cost, and lifecycle rules. Then Assign storage classes and transitions based on measured access patterns and compliance.
- Inspect BigQuery job statistics, query projections, filters, and data partitions. Then Rewrite queries to project required fields and prune partitions with cost monitoring.
- Inspect Dataproc CPU usage, YARN metrics, cluster autoscaling settings, and job boundaries. Then Apply a supported autoscaling policy or job-based execution with performance safeguards.
- Review reservation assignments, edition capacity, slot utilization, and job priorities. Then Choose an appropriate BigQuery Editions reservation arrangement and workload assignments.
Explanation
Correct Answer
C:Inspect Dataproc CPU usage, YARN metrics, cluster autoscaling settings, and job boundaries. Then Apply a supported autoscaling policy or job-based execution with performance safeguards. This sequence identifies the specific defect and follows it with an appropriate corrective change. Elastic batch processing should match provisioned workers to actual parallel workload demand. Acceptance check: A workload trial meets its deadline while unnecessary idle worker-hours decline.
Incorrect Answers
A:Review object access frequency, retention, retrieval cost, and lifecycle rules. Then Assign storage classes and transitions based on measured access patterns and compliance. 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 diagnosis and action: Inspect Dataproc CPU usage, YARN metrics, cluster autoscaling settings, and job boundaries. Then Apply a supported autoscaling policy or job-based execution with performance safeguards. The reason is that elastic batch processing should match provisioned workers to actual parallel workload demand.
B:Inspect BigQuery job statistics, query projections, filters, and data partitions. Then Rewrite queries to project required fields and prune partitions with cost monitoring. 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 diagnosis and action: Inspect Dataproc CPU usage, YARN metrics, cluster autoscaling settings, and job boundaries. Then Apply a supported autoscaling policy or job-based execution with performance safeguards. The reason is that elastic batch processing should match provisioned workers to actual parallel workload demand.
D:Review reservation assignments, edition capacity, slot utilization, and job priorities. Then Choose an appropriate BigQuery Editions reservation arrangement and workload assignments. 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 diagnosis and action: Inspect Dataproc CPU usage, YARN metrics, cluster autoscaling settings, and job boundaries. Then Apply a supported autoscaling policy or job-based execution with performance safeguards. The reason is that elastic batch processing should match provisioned workers to actual parallel workload demand.