Databricks Certified Data Engineer Professional Practice Test 74
Question 730
At Cascade Manufacturing, a notebook uses a third-party package also installed as a cluster library. Observed issue: A notebook-scoped installation overrides the expected cluster version. Before applying a fix, which investigation is most directly relevant?
- Compare production deployment variables with bundle target overrides
- Compare notebook and cluster package versions and import origins
- Compare deployed job JSON with the version-controlled bundle
- Compare job parameter definitions to hard-coded notebook literals
Explanation
Correct Answer
B:Compare notebook and cluster package versions and import origins. This checks the specific evidence behind a notebook-scoped installation overrides the expected cluster version. The runtime can resolve conflicting versions from different installation scopes. The investigation distinguishes the mechanism from an unrelated operational symptom.
Incorrect Answers
A:Compare production deployment variables with bundle target overrides. This diagnose action addresses a different case (bundle target overrides), where development job arguments were deployed into the production target. Bundle targets can override environment-specific variables and resource settings. In the stated problem, a notebook-scoped installation overrides the expected cluster version; this choice would not establish the required library precedence decision.
C:Compare deployed job JSON with the version-controlled bundle. This diagnose action addresses a different case (databricks cli resource updates), where production configuration drifts from repository source definitions. Declarative deployment describes resources as reviewed version-controlled artifacts. In the stated problem, a notebook-scoped installation overrides the expected cluster version; this choice would not establish the required library precedence decision.
D:Compare job parameter definitions to hard-coded notebook literals. This diagnose action addresses a different case (job parameters), where code contains hard-coded region IDs and catalog names. Task parameters allow runtime-specific values without changing notebook source. In the stated problem, a notebook-scoped installation overrides the expected cluster version; this choice would not establish the required library precedence decision.
Question 731
An architecture review at Northfield Analytics covers a workload where a production task can read source tables but fails writing its silver output. The unresolved constraint is: The run-as principal lacks MODIFY on the target table. Which design is most appropriate?
- Keep a supported dependency matrix for target runtimes
- Require named deployment targets and production approvals
- Grant only required target write access plus parent usage
- Require unit and integration tests plus deployment validation
Explanation
Correct Answer
C:Grant only required target write access plus parent usage. This design addresses the run-as principal lacks MODIFY on the target table. Unity Catalog authorization applies to the job execution identity. It establishes the right contract or architecture before execution changes.
Incorrect Answers
A:Maintain a supported dependency matrix for target runtimes. This design action addresses a different case (python dependency triage), where a package import error appears only on the target compute. Runtime-specific wheel compatibility and pinning must be tested in CI. In the stated problem, the run-as principal lacks MODIFY on the target table; this choice would not establish the required job run permission debug decision.
B:Require named deployment targets and production approvals. This design action addresses a different case (target-safe deployment), where the wrong workspace is selected because target is implicit. Explicit bundle target selection prevents accidental environment deployment. In the stated problem, the run-as principal lacks MODIFY on the target table; this choice would not establish the required job run permission debug decision.
D:Require unit and integration tests plus deployment validation. This design action addresses a different case (ci quality gates), where the deployment pipeline only checks YAML syntax. CI must run transformation tests and controlled integration checks before deployment. In the stated problem, the run-as principal lacks MODIFY on the target table; this choice would not establish the required job run permission debug decision.
Question 732
A data engineer at Horizon Travel must troubleshoot this case: rows with a nonnull region code should use a lookup while others retain an unknown label. Evidence: An unconditional inner join discards rows with missing region codes. What should be inspected first to confirm the failure mechanism?
- Inspect the streaming table definition and expectation violation counts
- Inspect existing expectation rules and failed-update event details
- Inspect join strategy and dimension size in the executed plan
- Inspect missing region codes and the output of the existing inner join
Explanation
Correct Answer
D:Inspect missing region codes and the output of the existing inner join. This checks the specific evidence behind an unconditional inner join discards rows with missing region codes. A left join with explicit CASE logic preserves rows while enriching those that match. The investigation distinguishes the mechanism from an unrelated operational symptom.
Incorrect Answers
A:Inspect the streaming table definition and expectation violation counts. This diagnose action addresses a different case (expectation drop action), where invalid rows currently reach downstream aggregates. A Lakeflow expectation configured to drop invalid rows filters violations from target output. In the stated problem, an unconditional inner join discards rows with missing region codes; this choice would not establish the required conditional enrichment decision.
B:Inspect existing expectation rules and failed-update event details. This diagnose action addresses a different case (expectation fail action), where the pipeline continues despite critical null records. Fail-on-violation expectations stop updates rather than silently filtering rows. In the stated problem, an unconditional inner join discards rows with missing region codes; this choice would not establish the required conditional enrichment decision.
C:Inspect join strategy and dimension size in the executed plan. This diagnose action addresses a different case (broadcast lookup table), where the join triggers a costly shuffle of the large fact dataset. Broadcasting an appropriately sized dimension can avoid a large shuffle join. In the stated problem, an unconditional inner join discards rows with missing region codes; this choice would not establish the required conditional enrichment decision.
Question 733
An architecture review at Cedar Brook Commerce covers a workload where a job should run data repair only after a quality check reports failure. The unresolved constraint is: Both the normal and repair tasks run despite a branching requirement. Which design is most appropriate?
- Branch downstream tasks using an If/else condition before divergent paths
- Make writes idempotent before enabling retries
- Postpone expensive materialization until the required action
- Model bronze as predecessor to both independent silver tasks
Explanation
Correct Answer
A:Branch downstream tasks using an If/else condition before divergent paths. This design addresses both the normal and repair tasks run despite a branching requirement. Lakeflow Jobs condition tasks can route downstream execution based on a result. It establishes the right contract or architecture before execution changes.
Incorrect Answers
B:Make writes idempotent before enabling retries. This design action addresses a different case (job retry semantics), where the downstream write repeats non-idempotent side effects on retry. Retries re-execute task logic; application code must protect repeated effects. In the stated problem, both the normal and repair tasks run despite a branching requirement; this choice would not establish the required conditional task branches decision.
C:Defer expensive materialization until the required action. This design action addresses a different case (spark lazy evaluation), where engineers assume an intermediate filter executed before any action. Spark transformations are lazy until an action triggers a job. In the stated problem, both the normal and repair tasks run despite a branching requirement; this choice would not establish the required conditional task branches decision.
D:Model bronze as predecessor to both independent silver tasks. This design action addresses a different case (job task dag), where dependent tasks sometimes run before the bronze load finishes. Lakeflow Job task dependencies form a directed acyclic execution graph. In the stated problem, both the normal and repair tasks run despite a branching requirement; this choice would not establish the required conditional task branches decision.
Question 734
At Oak Valley Retail, a platform team requires automated incident creation on failed jobs. Architecture constraint: Only personal email notifications are configured. Which design best addresses this requirement?
- Design a polling integration respecting API quotas and run state transitions
- Design an approved incident destination for failed job events
- Create a historical failure and runtime dashboard by workflow
- Configure failure notifications for the job to an approved on-call channel
Explanation
Correct Answer
B:Design an approved incident destination for failed job events. This design addresses only personal email notifications are configured. Supported job notification destinations can integrate workflow status with an incident system. It establishes the right contract or architecture before execution changes.
Incorrect Answers
A:Design a polling integration respecting API quotas and run state transitions. This design action addresses a different case (jobs rest monitoring), where a manual UI report omits failed tasks and paginated runs. The Jobs API exposes run records that a program can paginate and aggregate. In the stated problem, only personal email notifications are configured; this choice would not establish the required job webhook destination decision.
C:Create a historical failure and runtime dashboard by workflow. This design action addresses a different case (job operational history), where operators only see the most recent run in the Jobs UI. Jobs system records support historical analysis of runs and tasks. In the stated problem, only personal email notifications are configured; this choice would not establish the required job webhook destination decision.
D:Configure failure notifications for the job to an approved on-call channel. This design action addresses a different case (job email notification), where operators manually check the run page every morning. Lakeflow Jobs support status-triggered notifications for run outcomes. In the stated problem, only personal email notifications are configured; this choice would not establish the required job webhook destination decision.
Question 735
At Silver Ridge Logistics, a streaming pipeline fails only for one nested record. Architecture constraint: Re-running a huge source in development is slow and risky. Which design best addresses this requirement?
- Create a playbook mapping event classes to owner action
- Separate environment failures from business logic failures in triage
- Create a representative safe sample and separate test pipeline
- Define a parameterized replay process with idempotent writes
Explanation
Correct Answer
C:Create a representative safe sample and separate test pipeline. This design addresses re-running a huge source in development is slow and risky. A minimal reproducible input isolates the failure without modifying production data. It establishes the right contract or architecture before execution changes.
Incorrect Answers
A:Create a playbook mapping event classes to owner action. This design action addresses a different case (lakeflow event error classes), where the only visible dashboard status is FAILED without a dataset name. Pipeline event logs identify failing update and dataset messages. In the stated problem, re-running a huge source in development is slow and risky; this choice would not establish the required pipeline debug sampling decision.
B:Separate environment failures from business logic failures in triage. This design action addresses a different case (cluster log diagnostics), where the notebook cell shows only a generic stage failure. Driver and executor logs often contain the exact import or JVM error. In the stated problem, re-running a huge source in development is slow and risky; this choice would not establish the required pipeline debug sampling decision.
D:Define a parameterized replay process with idempotent writes. This design action addresses a different case (override run parameters), where the scheduler launches a full rebuild instead of rerunning the affected date. Job repair or rerun parameters can target a specific processing window. In the stated problem, re-running a huge source in development is slow and risky; this choice would not establish the required pipeline debug sampling decision.
Question 736
At Cascade Manufacturing, a monolithic notebook transformation cannot be tested separately. Architecture constraint: Business logic depends on notebook state and widgets. Which design best addresses this requirement?
- Separate fast local DataFrame unit tests from targeted integration suites
- Package shared transformations into importable modules with explicit dependencies
- Define environment-specific target values without forking business logic
- Refactor business rules as pure DataFrame transform functions
Explanation
Correct Answer
D:Refactor business rules as pure DataFrame transform functions. This design addresses business logic depends on notebook state and widgets. DataFrame.transform supports composable DataFrame-to-DataFrame functions. It establishes the right contract or architecture before execution changes.
Incorrect Answers
A:Separate fast local DataFrame unit tests from targeted integration suites. This design action addresses a different case (unit versus integration tests), where small logic regressions are discovered late and costly to debug. Unit tests isolate transformations while integration tests validate external contracts. In the stated problem, business logic depends on notebook state and widgets; this choice would not establish the required transform composability decision.
B:Package shared transformations into importable modules with explicit dependencies. This design action addresses a different case (python wheel packaging), where a refactor broke a notebook-relative import in the deployed job. A properly packaged versioned wheel gives Python code stable import paths outside notebooks. In the stated problem, business logic depends on notebook state and widgets; this choice would not establish the required transform composability decision.
C:Define environment-specific target values without forking business logic. This design action addresses a different case (bundle target overrides), where development job arguments were deployed into the production target. Bundle targets can override environment-specific variables and resource settings. In the stated problem, business logic depends on notebook state and widgets; this choice would not establish the required transform composability decision.
Question 737
Operations at Westridge Research owns a workload where a source string price unexpectedly arrives where a decimal is required. The previously identified issue was: Implicit type coercion risks invalid numeric values being stored. Which metric or audit check best detects drift?
- Monitor cast failure and schema drift counts
- Monitor expectation-drop counts and upstream correction rates
- Monitor invalid timezone offsets and parsing errors
- Monitor unexpected incompatible type changes
Explanation
Correct Answer
A:Monitor cast failure and schema drift counts. This watches the failure mode described by implicit type coercion risks invalid numeric values being stored. Schema validation and explicit casts make type conversion failures observable. It supplies a regression signal after remediation.
Incorrect Answers
B:Monitor expectation-drop counts and upstream correction rates. This monitor action addresses a different case (expectation drop action), where invalid rows currently reach downstream aggregates. A Lakeflow expectation configured to drop invalid rows filters violations from target output. In the stated problem, implicit type coercion risks invalid numeric values being stored; this choice would not establish the required silver schema enforcement decision.
C:Monitor invalid timezone offsets and parsing errors. This monitor action addresses a different case (timestamp timezone normalization), where events from different regions are ordered incorrectly in a UTC dashboard. Time-zone normalization is required before comparing timestamps from different sources. In the stated problem, implicit type coercion risks invalid numeric values being stored; this choice would not establish the required silver schema enforcement decision.
D:Monitor unexpected incompatible type changes. This monitor action addresses a different case (controlled schema evolution), where the silver writer rejects every new record after the upstream schema change. Schema evolution must be reviewed rather than enabling unrestricted acceptance for every column. In the stated problem, implicit type coercion risks invalid numeric values being stored; this choice would not establish the required silver schema enforcement decision.
Question 738
At Orion Capital, a stateful stream holds hundreds of millions of unexpired keys. The known risk is: Executor memory pressure grows even though input rate is stable. After remediation, which ongoing signal best detects recurrence?
- Monitor shuffle size per task and batch runtime
- Monitor state-store row counts, checkpoint size and spill
- Monitor hot-key frequencies and spill metrics
- Monitor cache hit rate and eviction pressure
Explanation
Correct Answer
B:Monitor state-store row counts, checkpoint size and spill. This watches the failure mode described by executor memory pressure grows even though input rate is stable. State retention and checkpoint state-store configuration affect memory requirements. It supplies a regression signal after remediation.
Incorrect Answers
A:Monitor shuffle size per task and batch runtime. This monitor action addresses a different case (shuffle partition count), where the current partition count is too low for data volume. Shuffle partition sizing affects memory pressure and task parallelism. In the stated problem, executor memory pressure grows even though input rate is stable; this choice would not establish the required streaming state growth decision.
C:Monitor hot-key frequencies and spill metrics. This monitor action addresses a different case (skewed joins), where a single join partition spills heavily to disk. Adaptive skew handling or key salting can mitigate a hot join key. In the stated problem, executor memory pressure grows even though input rate is stable; this choice would not establish the required streaming state growth decision.
D:Monitor cache hit rate and eviction pressure. This monitor action addresses a different case (cache reuse), where repeated recomputation dominates each branch's execution. Persistence can avoid repeated work if reused data fits the memory budget. In the stated problem, executor memory pressure grows even though input rate is stable; this choice would not establish the required streaming state growth decision.
Question 739
At Lakewood Distribution, a filter on event_date scans nearly all Delta files. Observed issue: File-level statistics are missing for the filter column. Before applying a fix, which investigation is most directly relevant?
- Inspect executed plan for AQE decisions and stage statistics
- Inspect table ownership and whether external storage paths are actually required
- Inspect table stats collection and skipped-file counts
- Inspect filters and partition scan counts in the physical plan
Explanation
Correct Answer
C:Inspect table stats collection and skipped-file counts. This checks the specific evidence behind file-level statistics are missing for the filter column. Delta data skipping uses collected column statistics to eliminate files. The investigation distinguishes the mechanism from an unrelated operational symptom.
Incorrect Answers
A:Inspect executed plan for AQE decisions and stage statistics. This diagnose action addresses a different case (adaptive execution), where static join strategy performs poorly at varying input volumes. Adaptive Query Execution can adjust supported shuffle partitions and join strategies at runtime. In the stated problem, file-level statistics are missing for the filter column; this choice would not establish the required data skipping statistics decision.
B:Inspect table ownership and whether external storage paths are actually required. This diagnose action addresses a different case (managed table maintenance), where each table has custom file cleanup jobs and broad storage permissions. Unity Catalog managed tables provide platform-managed data placement and maintenance capabilities. In the stated problem, file-level statistics are missing for the filter column; this choice would not establish the required data skipping statistics decision.
D:Inspect filters and partition scan counts in the physical plan. This diagnose action addresses a different case (partition pruning), where a query wraps business_date in a transformation and reads many partitions. Direct predicates on partition keys can enable partition pruning. In the stated problem, file-level statistics are missing for the filter column; this choice would not establish the required data skipping statistics decision.
Question 740
At Bayview Insurance, a production workflow runs as the notebook author's personal identity. Architecture constraint: An employee departure causes permissions failures during scheduled runs. Which design best addresses this requirement?
- Add representative expected DataFrame fixtures and schema assertions
- Move resource definitions into bundle YAML with review gates
- Use one managed and repeatable dependency source for the workload
- Use a managed service principal with only required production privileges
Explanation
Correct Answer
D:Use a managed service principal with only required production privileges. This design addresses an employee departure causes permissions failures during scheduled runs. A stable least-privilege service principal can provide durable job identity. It establishes the right contract or architecture before execution changes.
Incorrect Answers
A:Add representative expected DataFrame fixtures and schema assertions. This design action addresses a different case (dataframe testing), where tests only assert that the DataFrame is nonempty. DataFrame equality and schema assertions test data behavior and contracts. In the stated problem, an employee departure causes permissions failures during scheduled runs; this choice would not establish the required job run-as identity decision.
B:Move resource definitions into bundle YAML with review gates. This design action addresses a different case (databricks cli resource updates), where production configuration drifts from repository source definitions. Declarative deployment describes resources as reviewed version-controlled artifacts. In the stated problem, an employee departure causes permissions failures during scheduled runs; this choice would not establish the required job run-as identity decision.
C:Use one managed and repeatable dependency source for the workload. This design action addresses a different case (library precedence), where a notebook-scoped installation overrides the expected cluster version. The runtime can resolve conflicting versions from different installation scopes. In the stated problem, an employee departure causes permissions failures during scheduled runs; this choice would not establish the required job run-as identity decision.