Databricks Certified Data Engineer Professional Practice Test 78
Question 770
Operations at Silver Ridge Logistics owns a workload where a data engineering job accesses a protected external API. The previously identified issue was: An API token is committed in a Python notebook tracked in Git. Which metric or audit check best detects drift?
- Monitor Python worker execution time and error rates
- Audit access to the secret scope and changes to job identity
- Detect unexpected package version changes in startup validation
- Detect unmanaged changes to deployed job resources
Explanation
Correct Answer
B:Audit access to the secret scope and changes to job identity. This watches the failure mode described by an API token is committed in a Python notebook tracked in Git. Secret-backed configuration avoids embedding credentials in notebooks or deployment YAML. It supplies a regression signal after remediation.
Incorrect Answers
A:Monitor Python worker execution time and error rates. This monitor action addresses a different case (vectorized udf), where row-by-row Python invocation dominates stage runtime. Pandas UDFs process batches through Arrow rather than per-row Python calls. In the stated problem, an API token is committed in a Python notebook tracked in Git; this choice would not establish the required secure configuration decision.
C:Detect unexpected package version changes in startup validation. This monitor 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 API token is committed in a Python notebook tracked in Git; this choice would not establish the required secure configuration decision.
D:Detect unmanaged changes to deployed job resources. This monitor 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 API token is committed in a Python notebook tracked in Git; this choice would not establish the required secure configuration decision.
Question 771
A data engineer at Granite Edge Labs must troubleshoot this case: a provider exposes a whole schema when only one vetted table was approved. Evidence: The recipient can discover unintended datasets. What should be inspected first to confirm the failure mechanism?
- Inspect intended recipient identity and existing share membership
- Inspect recipient credential expiration and access history
- Inspect share contents and approved sharing manifest
- Confirm recipient platform and supported open-sharing connector
Explanation
Correct Answer
C:Inspect share contents and approved sharing manifest. This checks the specific evidence behind the recipient can discover unintended datasets. A Delta Sharing share should contain only explicitly approved assets. The investigation distinguishes the mechanism from an unrelated operational symptom.
Incorrect Answers
A:Inspect intended recipient identity and existing share membership. This diagnose action addresses a different case (d2d managed recipient), where a recipient team copies files manually and loses timely updates. Databricks-to-Databricks Delta Sharing supports governed live access without manual copying. In the stated problem, the recipient can discover unintended datasets; this choice would not establish the required share catalog scope decision.
B:Inspect recipient credential expiration and access history. This diagnose action addresses a different case (sharing credential rotation), where partners risk losing access or using a leaked long-lived credential. Credential rotation must be coordinated without unnecessarily broadening permissions. In the stated problem, the recipient can discover unintended datasets; this choice would not establish the required share catalog scope decision.
D:Confirm recipient platform and supported open-sharing connector. This diagnose action addresses a different case (open protocol recipient), where the partner cannot use an internal Databricks-to-Databricks credential flow. Open Delta Sharing can support non-Databricks recipients using the sharing protocol. In the stated problem, the recipient can discover unintended datasets; this choice would not establish the required share catalog scope decision.
Question 772
At Lakewood Distribution, a team wants governed read access to a supported external relational database. Observed issue: Engineers export the full source database into cloud object storage each hour. Before applying a fix, which investigation is most directly relevant?
- Inspect USE CATALOG, USE SCHEMA and SELECT grants for the identity
- Compare provider update timestamps with consumer query snapshots
- Confirm recipient platform and supported open-sharing connector
- Check whether the external source and connector are supported
Explanation
Correct Answer
D:Check whether the external source and connector are supported. This checks the specific evidence behind engineers export the full source database into cloud object storage each hour. Lakehouse Federation can query supported external sources through a catalog connection. The investigation distinguishes the mechanism from an unrelated operational symptom.
Incorrect Answers
A:Inspect USE CATALOG, USE SCHEMA and SELECT grants for the identity. This diagnose action addresses a different case (foreign catalog permission), where catalog discovery was mistaken for full table access. Unity Catalog usage and object privileges are still required for foreign data objects. In the stated problem, engineers export the full source database into cloud object storage each hour; this choice would not establish the required federated connection decision.
B:Compare provider update timestamps with consumer query snapshots. This diagnose action addresses a different case (shared table freshness), where consumers assume the share is a nightly static export. Delta Sharing exposes current authorized data as the provider updates the source. In the stated problem, engineers export the full source database into cloud object storage each hour; this choice would not establish the required federated connection decision.
C:Confirm recipient platform and supported open-sharing connector. This diagnose action addresses a different case (open protocol recipient), where the partner cannot use an internal Databricks-to-Databricks credential flow. Open Delta Sharing can support non-Databricks recipients using the sharing protocol. In the stated problem, engineers export the full source database into cloud object storage each hour; this choice would not establish the required federated connection decision.
Question 773
Operations at Horizon Travel owns a workload where a source produces multiple records for each business key. The previously identified issue was: The pipeline picks an arbitrary record instead of the newest sequence. Which metric or audit check best detects drift?
- Monitor new tie cases that would make ordering nondeterministic
- Monitor new per-key ordering collisions
- Track coverage and test failures for changed transformation functions
- Monitor plan regressions that reintroduce Python evaluation
Explanation
Correct Answer
A:Monitor new tie cases that would make ordering nondeterministic. This watches the failure mode described by the pipeline picks an arbitrary record instead of the newest sequence. ROW_NUMBER ordered by a deterministic sequence within each key selects the desired latest row. It supplies a regression signal after remediation.
Incorrect Answers
B:Monitor new per-key ordering collisions. This monitor action addresses a different case (cdc duplicate sequence), where the processing order for tied source events is nondeterministic. A deterministic sequencing contract needs a unique ordered event position. In the stated problem, the pipeline picks an arbitrary record instead of the newest sequence; this choice would not establish the required window latest record decision.
C:Track coverage and test failures for changed transformation functions. This monitor 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, the pipeline picks an arbitrary record instead of the newest sequence; this choice would not establish the required window latest record decision.
D:Monitor plan regressions that reintroduce Python evaluation. This monitor action addresses a different case (avoid python udf for sql), where the Python UDF creates an avoidable cross-language execution boundary. Built-in Spark SQL functions can execute in optimized expressions without Python UDF overhead. In the stated problem, the pipeline picks an arbitrary record instead of the newest sequence; this choice would not establish the required window latest record decision.
Question 774
Operations at Pinecrest Holdings owns a workload where a Delta fact table receives thousands of tiny append files per hour. The previously identified issue was: Read overhead grows because query plans open excessive small files. Which metric or audit check best detects drift?
- Monitor managed table optimization and ownership changes
- Monitor small-file accumulation and optimization jobs
- Monitor query scans and available column stats
- Monitor plans that lose partition pruning
Explanation
Correct Answer
B:Monitor small-file accumulation and optimization jobs. This watches the failure mode described by read overhead grows because query plans open excessive small files. OPTIMIZE can compact compatible Delta files without changing logical table contents. It supplies a regression signal after remediation.
Incorrect Answers
A:Monitor managed table optimization and ownership changes. This monitor 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, read overhead grows because query plans open excessive small files; this choice would not establish the required small file compaction decision.
C:Monitor query scans and available column stats. This monitor action addresses a different case (data skipping statistics), where file-level statistics are missing for the filter column. Delta data skipping uses collected column statistics to eliminate files. In the stated problem, read overhead grows because query plans open excessive small files; this choice would not establish the required small file compaction decision.
D:Monitor plans that lose partition pruning. This monitor 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, read overhead grows because query plans open excessive small files; this choice would not establish the required small file compaction decision.
Question 775
At Horizon Travel, rows with a nonnull region code should use a lookup while others retain an unknown label. A change is required because: An unconditional inner join discards rows with missing region codes. Which implementation action most directly corrects the configuration?
- Use MERGE with matched update and not-matched insert branches
- Apply row_number partitioned by key with explicit descending sequence
- Apply LEFT JOIN and CASE WHEN or COALESCE to the region output
- Add a supported expectation with ON VIOLATION DROP ROW to the dataset definition
Explanation
Correct Answer
C:Apply LEFT JOIN and CASE WHEN or COALESCE to the region output. This directly changes the feature or logic 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. It is the concrete configuration for the stated incident.
Incorrect Answers
A:Use MERGE with matched update and not-matched insert branches. This implement action addresses a different case (cdc merge semantics), where the current INSERT-only target contains duplicate customer keys. A keyed Delta MERGE can update existing rows and insert new keys. 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:Apply row_number partitioned by key with explicit descending sequence. This implement action addresses a different case (latest-per-key with ties), where two events have the same event time and yield different surviving rows. A deterministic tie-breaker is required in a per-key window ranking. In the stated problem, an unconditional inner join discards rows with missing region codes; this choice would not establish the required conditional enrichment decision.
D:Add a supported expectation with ON VIOLATION DROP ROW to the dataset definition. This implement 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.
Question 776
At Cascade Manufacturing, a pipeline expectation dashboard shows records failing a rule. The known risk is: Analysts misread a quality count as the number of pipeline task failures. After remediation, which ongoing signal best detects recurrence?
- Monitor expectation-drop counts and upstream correction rates
- Monitor max task duration and hot-key distribution
- Alert on increasing quarantine rates and source schemas
- Trend both quality failure rates and pipeline status separately
Explanation
Correct Answer
D:Trend both quality failure rates and pipeline status separately. This watches the failure mode described by analysts misread a quality count as the number of pipeline task failures. Expectation metrics describe data rows and must be interpreted separately from orchestration status. It supplies a regression signal after remediation.
Incorrect Answers
A: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, analysts misread a quality count as the number of pipeline task failures; this choice would not establish the required quality metric interpretation decision.
B:Monitor max task duration and hot-key distribution. This monitor action addresses a different case (skewed group aggregation), where a single campaign dominates rows and one reduce task runs for minutes. A hot aggregation key causes skew despite ample parallelism. In the stated problem, analysts misread a quality count as the number of pipeline task failures; this choice would not establish the required quality metric interpretation decision.
C:Alert on increasing quarantine rates and source schemas. This monitor action addresses a different case (quarantine bad records), where dropping invalid rows silently hides upstream quality failures. Quarantine preserves invalid events separately while allowing valid records through. In the stated problem, analysts misread a quality count as the number of pipeline task failures; this choice would not establish the required quality metric interpretation decision.
Question 777
At Horizon Travel, rows with a nonnull region code should use a lookup while others retain an unknown label. A change was deployed to address: An unconditional inner join discards rows with missing region codes. Which test result provides the strongest evidence that the requirement is now met?
- Confirm rows with and without region codes both appear correctly
- Inject an invalid record and confirm the update fails visibly
- Confirm the plan uses the intended broadcast join and results match
- Replay duplicate IDs within the accepted window and confirm only one survives
Explanation
Correct Answer
A:Confirm rows with and without region codes both appear correctly. This tests the expected result against an unconditional inner join discards rows with missing region codes, not simply whether a job or object exists. A left join with explicit CASE logic preserves rows while enriching those that match.
Incorrect Answers
B:Inject an invalid record and confirm the update fails visibly. This validate 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:Confirm the plan uses the intended broadcast join and results match. This validate 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.
D:Replay duplicate IDs within the accepted window and confirm only one survives. This validate action addresses a different case (streaming dedup watermark), where a plain dropDuplicates retains state without a practical bound for never-ending keys. Watermarked streaming deduplication can bound retained duplicate state under an explicit lateness policy. 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 778
At Granite Edge Labs, a complex aggregation fails repeatedly under memory pressure. A change is required because: Operators increase driver memory but failures occur on executors. Which implementation action most directly corrects the configuration?
- Repair the failed run with corrected inputs or code and selected task scope
- Adjust appropriate shuffle or executor settings based on evidence
- Correct the missing dependency or incompatible runtime package
- Add relevant test jobs and environment approval gates to the pipeline
Explanation
Correct Answer
B:Adjust appropriate shuffle or executor settings based on evidence. This directly changes the feature or logic behind operators increase driver memory but failures occur on executors. Spark UI task failures and shuffle/spill metrics distinguish worker pressure from driver issues. It is the concrete configuration for the stated incident.
Incorrect Answers
A:Repair the failed run with corrected inputs or code and selected task scope. This implement action addresses a different case (repair failed tasks), where operators rerun the entire job and duplicate completed side effects. Repair runs can rerun failed or selected tasks while preserving successful predecessor work under supported semantics. In the stated problem, operators increase driver memory but failures occur on executors; this choice would not establish the required spark ui failure stage decision.
C:Correct the missing dependency or incompatible runtime package. This implement 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, operators increase driver memory but failures occur on executors; this choice would not establish the required spark ui failure stage decision.
D:Add relevant test jobs and environment approval gates to the pipeline. This implement 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, operators increase driver memory but failures occur on executors; this choice would not establish the required spark ui failure stage decision.
Question 779
At Redwood Civic Services, data engineers need access to a shared external cloud storage prefix. Architecture constraint: Raw cloud permissions bypass central catalog governance. Which design best addresses this requirement?
- Assign distinct development and production catalogs with separate grants
- Grant parent usage plus specific SELECT rather than broad ownership
- Use a narrowly scoped external location with a controlled storage credential
- Choose approved managed storage locations for governed tables
Explanation
Correct Answer
C:Use a narrowly scoped external location with a controlled storage credential. This design addresses raw cloud permissions bypass central catalog governance. External locations map cloud paths to governed Unity Catalog storage credentials. It establishes the right contract or architecture before execution changes.
Incorrect Answers
A:Assign distinct development and production catalogs with separate grants. This design action addresses a different case (environment catalog isolation), where both environments use the same default catalog name in notebooks. Environment-specific catalogs and explicit target names reduce cross-environment writes. In the stated problem, raw cloud permissions bypass central catalog governance; this choice would not establish the required external location governance decision.
B:Grant parent usage plus specific SELECT rather than broad ownership. This design action addresses a different case (catalog privilege inheritance), where the team lacks USE CATALOG and USE SCHEMA on the parent containers. Unity Catalog object access generally requires relevant parent usage privileges. In the stated problem, raw cloud permissions bypass central catalog governance; this choice would not establish the required external location governance decision.
D:Choose approved managed storage locations for governed tables. This design action addresses a different case (managed storage ownership), where the data platform cannot apply consistent lifecycle governance. Managed locations centralize storage ownership for Unity Catalog managed assets. In the stated problem, raw cloud permissions bypass central catalog governance; this choice would not establish the required external location governance decision.
Question 780
At Summit Consumer Goods, a team directly edits shared production notebook code in the workspace. Architecture constraint: There is no controlled code review or rollback history. Which design best addresses this requirement?
- Define a controlled change-management path for resource configuration
- Plan rollback of code/resources while protecting compatible state and schema
- Require unit and integration tests plus deployment validation
- Use branch-based review and merge before deployment
Explanation
Correct Answer
D:Use branch-based review and merge before deployment. This design addresses there is no controlled code review or rollback history. Databricks Git folders connect workspace development to version control. It establishes the right contract or architecture before execution changes.
Incorrect Answers
A:Define a controlled change-management path for resource configuration. This design action addresses a different case (unmanaged resource drift), where subsequent CI redeployment unexpectedly overwrites it. Declarative source of truth should include intentional job-resource changes. In the stated problem, there is no controlled code review or rollback history; this choice would not establish the required git folder collaboration decision.
B:Plan rollback of code/resources while protecting compatible state and schema. This design action addresses a different case (rollback deployment), where deployers have no record of the previous working configuration. Versioned bundle releases enable controlled rollback to a known commit. In the stated problem, there is no controlled code review or rollback history; this choice would not establish the required git folder collaboration decision.
C: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, there is no controlled code review or rollback history; this choice would not establish the required git folder collaboration decision.