Databricks Certified Data Engineer Professional Practice Test 7
Question 60
A data engineer at Summit Consumer Goods must troubleshoot this case: an orchestrator retries a failed object-storage batch. Evidence: A partially processed input file is loaded twice into Delta. What should be inspected first to confirm the failure mechanism?
- Inspect representative raw lines and parser quote/escape settings
- Inspect file media types and current input source format
- Inspect file-discovery backlog and the source format configuration
- Inspect duplicate file IDs and the ingestion checkpoint state
Explanation
Correct Answer
D:Inspect duplicate file IDs and the ingestion checkpoint state. This checks the specific evidence behind a partially processed input file is loaded twice into Delta. Checkpointed incremental ingestion or stable event-level deduplication prevents repeated effects. The investigation distinguishes the mechanism from an unrelated operational symptom.
Incorrect Answers
A:Inspect representative raw lines and parser quote/escape settings. This diagnose action addresses a different case (malformed csv quotes), where an ingestion reader splits quoted names into extra columns. CSV quoting and escape configurations must match the source serialization. In the stated problem, a partially processed input file is loaded twice into Delta; this choice would not establish the required retry-safe file loads decision.
B:Inspect file media types and current input source format. This diagnose action addresses a different case (binary payload metadata), where a line-oriented text reader corrupts the raw binary payload. binaryFile input preserves raw file bytes and path metadata rather than decoding lines. In the stated problem, a partially processed input file is loaded twice into Delta; this choice would not establish the required retry-safe file loads decision.
C:Inspect file-discovery backlog and the source format configuration. This diagnose action addresses a different case (auto loader file discovery), where listing the full historical directory every run exceeds the ingestion SLA. Auto Loader is designed for incremental new-file discovery with persisted state. In the stated problem, a partially processed input file is loaded twice into Delta; this choice would not establish the required retry-safe file loads decision.
Question 61
At Orion Capital, a pipeline's source ingestion finishes quickly but the published gold table is stale. A change is required because: Operators monitor compute uptime rather than data freshness. Which implementation action most directly corrects the configuration?
- Record stage timestamps and expose a freshness query
- Capture supported query-history metrics in a restricted view
- Apply the data-skipping-friendly predicate or clustering update
- Query jobs system tables with appropriate retention-aware time filters
Explanation
Correct Answer
A:Record stage timestamps and expose a freshness query. This directly changes the feature or logic behind operators monitor compute uptime rather than data freshness. SLA monitoring should measure source event time to published table availability. It is the concrete configuration for the stated incident.
Incorrect Answers
B:Capture supported query-history metrics in a restricted view. This implement action addresses a different case (sql query history), where no baseline is available for the warehouse query execution. Query history/system query records support comparison of execution time and workload. In the stated problem, operators monitor compute uptime rather than data freshness; this choice would not establish the required end-to-end sla decision.
C:Apply the data-skipping-friendly predicate or clustering update. This implement action addresses a different case (query profile scans), where operators assume the query is always CPU-bound. Query Profile identifies scan, pruning and shuffle behavior for SQL workloads. In the stated problem, operators monitor compute uptime rather than data freshness; this choice would not establish the required end-to-end sla decision.
D:Query jobs system tables with appropriate retention-aware time filters. This implement 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, operators monitor compute uptime rather than data freshness; this choice would not establish the required end-to-end sla decision.
Question 62
A deployment owner at Riverbend Energy needs to implement a remedy: a four-task Lakeflow Job has one failed downstream task after three predecessors succeeded. The present failure is: Operators rerun the entire job and duplicate completed side effects. Which change should be applied?
- Connect a Git folder and deploy from an approved commit
- Repair the failed run with corrected inputs or code and selected task scope
- Deploy using an explicit reviewed production target
- Supply the corrected date parameter in a supported rerun or repair
Explanation
Correct Answer
B:Repair the failed run with corrected inputs or code and selected task scope. This directly changes the feature or logic behind 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. It is the concrete configuration for the stated incident.
Incorrect Answers
A:Connect a Git folder and deploy from an approved commit. This implement action addresses a different case (git folder collaboration), where there is no controlled code review or rollback history. Databricks Git folders connect workspace development to version control. In the stated problem, operators rerun the entire job and duplicate completed side effects; this choice would not establish the required repair failed tasks decision.
C:Deploy using an explicit reviewed production target. This implement 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, operators rerun the entire job and duplicate completed side effects; this choice would not establish the required repair failed tasks decision.
D:Supply the corrected date parameter in a supported rerun or repair. This implement 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, operators rerun the entire job and duplicate completed side effects; this choice would not establish the required repair failed tasks decision.
Question 63
An architecture review at Oak Valley Retail covers a workload where source customer identifiers can be reused following account mergers. The unresolved constraint is: Joining facts directly on mutable business IDs links history incorrectly. Which design is most appropriate?
- Define a common country dimension with agreed identifiers and attributes
- Model Type 2 records with effective intervals and current-row flag
- Use immutable surrogate dimension keys mapped from source business IDs
- Design a customer-plan bridge with valid membership periods
Explanation
Correct Answer
C:Use immutable surrogate dimension keys mapped from source business IDs. This design addresses joining facts directly on mutable business IDs links history incorrectly. Stable surrogate keys decouple dimensional identity from changing source identifiers. It establishes the right contract or architecture before execution changes.
Incorrect Answers
A:Define a common country dimension with agreed identifiers and attributes. This design action addresses a different case (conformed dimensions), where the same country appears under conflicting dimension keys across marts. A conformed dimension provides common attribute definitions across fact models. In the stated problem, joining facts directly on mutable business IDs links history incorrectly; this choice would not establish the required surrogate dimension keys decision.
B:Model Type 2 records with effective intervals and current-row flag. This design action addresses a different case (scd type 2 effective dates), where a single current tier overwrites history in the dimension. SCD Type 2 stores effective start/end intervals for distinct historical dimension versions. In the stated problem, joining facts directly on mutable business IDs links history incorrectly; this choice would not establish the required surrogate dimension keys decision.
D:Design a customer-plan bridge with valid membership periods. This design action addresses a different case (many-to-many bridge), where joining facts directly to the membership table multiplies totals. A bridge table models many-to-many relationships at an explicit membership grain. In the stated problem, joining facts directly on mutable business IDs links history incorrectly; this choice would not establish the required surrogate dimension keys decision.
Question 64
At Pinecrest Holdings, a failed regional load has the wrong processing date. The known risk is: The scheduler launches a full rebuild instead of rerunning the affected date. After remediation, which ongoing signal best detects recurrence?
- Monitor direct edits that bypass Git review
- Monitor pipeline error events by dataset and update
- Monitor dependency-related task failure signatures
- Monitor unexpected parameter overrides across runs
Explanation
Correct Answer
D:Monitor unexpected parameter overrides across runs. This watches the failure mode described by the scheduler launches a full rebuild instead of rerunning the affected date. Job repair or rerun parameters can target a specific processing window. It supplies a regression signal after remediation.
Incorrect Answers
A:Monitor direct edits that bypass Git review. This monitor action addresses a different case (git folder collaboration), where there is no controlled code review or rollback history. Databricks Git folders connect workspace development to version control. In the stated problem, the scheduler launches a full rebuild instead of rerunning the affected date; this choice would not establish the required override run parameters decision.
B:Monitor pipeline error events by dataset and update. This monitor 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, the scheduler launches a full rebuild instead of rerunning the affected date; this choice would not establish the required override run parameters decision.
C:Monitor dependency-related task failure signatures. This monitor 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, the scheduler launches a full rebuild instead of rerunning the affected date; this choice would not establish the required override run parameters decision.
Question 65
Quality assurance at Vantage Security checks a corrected workload where a raw ingestion feed occasionally contains personal identifiers in a supposedly anonymized field. The original fault was: The silver pipeline allows unexpected identifiers into a broad analyst dataset. Which verification is most decisive?
- Inject test identifiers and verify they are not in analyst-facing output
- Trigger a test error and confirm logs reveal no PII content
- Query as privileged and standard readers and verify intended masked values
- Verify subject absence from all in-scope queryable datasets
Explanation
Correct Answer
A:Inject test identifiers and verify they are not in analyst-facing output. This tests the expected result against the silver pipeline allows unexpected identifiers into a broad analyst dataset, not simply whether a job or object exists. A data-quality filter can isolate suspect records before release.
Incorrect Answers
B:Trigger a test error and confirm logs reveal no PII content. This validate action addresses a different case (restricted event logging), where logs expose PII to broader operations readers. Logging should redact or omit sensitive payload fields while preserving diagnostic codes. In the stated problem, the silver pipeline allows unexpected identifiers into a broad analyst dataset; this choice would not establish the required pii quarantine decision.
C:Query as privileged and standard readers and verify intended masked values. This validate action addresses a different case (column masking), where a raw SELECT on an approved table exposes plaintext email. Unity Catalog column masks can transform sensitive values at read time. In the stated problem, the silver pipeline allows unexpected identifiers into a broad analyst dataset; this choice would not establish the required pii quarantine decision.
D:Verify subject absence from all in-scope queryable datasets. This validate action addresses a different case (data subject request), where deleting a row from only the gold table leaves copies elsewhere. A complete delete workflow tracks identifiers and propagation across all governed copies. In the stated problem, the silver pipeline allows unexpected identifiers into a broad analyst dataset; this choice would not establish the required pii quarantine decision.
Question 66
At Meadowland Software, a critical table remains owned by a departed contractor. The known risk is: New data stewards cannot maintain its grants. After remediation, which ongoing signal best detects recurrence?
- Monitor new unapproved lineage dependencies
- Monitor ownership transfers and stale personal owners
- Audit unapproved external paths and location changes
- Monitor unexpected new tables entering the governed schema
Explanation
Correct Answer
B:Monitor ownership transfers and stale personal owners. This watches the failure mode described by new data stewards cannot maintain its grants. Unity Catalog ownership should be assigned to a maintained principal. It supplies a regression signal after remediation.
Incorrect Answers
A:Monitor new unapproved lineage dependencies. This monitor action addresses a different case (lineage tracking), where investigators cannot tell which upstream transformation produced it. Unity Catalog lineage records relationships between governed data assets. In the stated problem, new data stewards cannot maintain its grants; this choice would not establish the required ownership reassignment decision.
C:Audit unapproved external paths and location changes. This monitor 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, new data stewards cannot maintain its grants; this choice would not establish the required ownership reassignment decision.
D:Monitor unexpected new tables entering the governed schema. This monitor action addresses a different case (schema-level grant inheritance), where analysts must repeatedly request identical SELECT grants for each table. Unity Catalog schema-level privileges can apply to existing and future child objects. In the stated problem, new data stewards cannot maintain its grants; this choice would not establish the required ownership reassignment decision.
Question 67
At Westhaven Services, a CDC source occasionally emits two records for one key at the same sequence number. The known risk is: The processing order for tied source events is nondeterministic. After remediation, which ongoing signal best detects recurrence?
- Monitor backlog growth and sustained microbatch duration
- Monitor out-of-order changes and CDC application errors
- Monitor new per-key ordering collisions
- Monitor new tie cases that would make ordering nondeterministic
Explanation
Correct Answer
C:Monitor new per-key ordering collisions. This watches the failure mode described by the processing order for tied source events is nondeterministic. A deterministic sequencing contract needs a unique ordered event position. It supplies a regression signal after remediation.
Incorrect Answers
A:Monitor backlog growth and sustained microbatch duration. This monitor action addresses a different case (streaming trigger tuning), where microbatch processing time exceeds the configured trigger interval. Shortening a trigger cannot make a saturated single streaming query process overlapping batches faster. In the stated problem, the processing order for tied source events is nondeterministic; this choice would not establish the required cdc duplicate sequence decision.
B:Monitor out-of-order changes and CDC application errors. This monitor action addresses a different case (auto cdc keys), where applying events as append-only rows leaves outdated active accounts. AUTO CDC or applicable APPLY CHANGES needs stable keys and sequence ordering for stateful upserts. In the stated problem, the processing order for tied source events is nondeterministic; this choice would not establish the required cdc duplicate sequence decision.
D:Monitor new tie cases that would make ordering nondeterministic. This monitor action addresses a different case (window latest record), where 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. In the stated problem, the processing order for tied source events is nondeterministic; this choice would not establish the required cdc duplicate sequence decision.
Question 68
Quality assurance at Eastern Star Foods checks a corrected workload where a cloud object store receives a large and growing set of landing files. The original fault was: Listing the full historical directory every run exceeds the ingestion SLA. Which verification is most decisive?
- Replay the failed batch and verify each source event appears once
- Run two distinct batches and confirm both histories remain accessible
- Restart the job and verify no duplicate committed records
- Append one new object and verify it is ingested only once
Explanation
Correct Answer
D:Append one new object and verify it is ingested only once. This tests the expected result against listing the full historical directory every run exceeds the ingestion SLA, not simply whether a job or object exists. Auto Loader is designed for incremental new-file discovery with persisted state.
Incorrect Answers
A:Replay the failed batch and verify each source event appears once. This validate action addresses a different case (retry-safe file loads), where a partially processed input file is loaded twice into Delta. Checkpointed incremental ingestion or stable event-level deduplication prevents repeated effects. In the stated problem, listing the full historical directory every run exceeds the ingestion SLA; this choice would not establish the required auto loader file discovery decision.
B:Run two distinct batches and confirm both histories remain accessible. This validate action addresses a different case (append-only delta bronze), where a nightly overwrite accidentally removes historical audit events. Append-only ingestion keeps previous raw records while adding new batches. In the stated problem, listing the full historical directory every run exceeds the ingestion SLA; this choice would not establish the required auto loader file discovery decision.
C:Restart the job and verify no duplicate committed records. This validate action addresses a different case (kafka offset durability), where restarting with a fresh checkpoint replays previously ingested messages. A stable streaming checkpoint maintains Kafka offsets and sink progress across restarts. In the stated problem, listing the full historical directory every run exceeds the ingestion SLA; this choice would not establish the required auto loader file discovery decision.
Question 69
A deployment owner at Vantage Security needs to implement a remedy: an open-sharing recipient's credential is nearing expiration. The present failure is: Partners risk losing access or using a leaked long-lived credential. Which change should be applied?
- Rotate the recipient credential according to the supported sharing workflow
- Create a scoped sharing recipient and distribute credentials through an approved channel
- Apply minimal catalog, schema and table grants for the analyst
- Remove unapproved assets and add only the vetted table to the share
Explanation
Correct Answer
A:Rotate the recipient credential according to the supported sharing workflow. This directly changes the feature or logic behind partners risk losing access or using a leaked long-lived credential. Credential rotation must be coordinated without unnecessarily broadening permissions. It is the concrete configuration for the stated incident.
Incorrect Answers
B:Create a scoped sharing recipient and distribute credentials through an approved channel. This implement 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, partners risk losing access or using a leaked long-lived credential; this choice would not establish the required sharing credential rotation decision.
C:Apply minimal catalog, schema and table grants for the analyst. This implement 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, partners risk losing access or using a leaked long-lived credential; this choice would not establish the required sharing credential rotation decision.
D:Remove unapproved assets and add only the vetted table to the share. This implement action addresses a different case (share catalog scope), where the recipient can discover unintended datasets. A Delta Sharing share should contain only explicitly approved assets. In the stated problem, partners risk losing access or using a leaked long-lived credential; this choice would not establish the required sharing credential rotation decision.
Question 70
Quality assurance at Harborline Utilities checks a corrected workload where a job repair reruns an external notification task. The original fault was: Customers receive repeated notifications for the same batch. Which verification is most decisive?
- Rerun and verify the intended write succeeds while other tables stay blocked
- Repair the task and verify one notification per batch
- Rotate the human token and verify CI deployment still authenticates
- Verify only the intended date partition is recalculated
Explanation
Correct Answer
B:Repair the task and verify one notification per batch. This tests the expected result against customers receive repeated notifications for the same batch, not simply whether a job or object exists. Task retries need idempotent side effects even when upstream work is reused.
Incorrect Answers
A:Rerun and verify the intended write succeeds while other tables stay blocked. This validate action addresses a different case (job run permission debug), where the run-as principal lacks MODIFY on the target table. Unity Catalog authorization applies to the job execution identity. In the stated problem, customers receive repeated notifications for the same batch; this choice would not establish the required idempotent retry repair decision.
C:Rotate the human token and verify CI deployment still authenticates. This validate action addresses a different case (api deployment authentication), where scheduled production deployment fails when the developer's token expires. Workload identity or service principal authentication decouples CI from employees. In the stated problem, customers receive repeated notifications for the same batch; this choice would not establish the required idempotent retry repair decision.
D:Verify only the intended date partition is recalculated. This validate 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, customers receive repeated notifications for the same batch; this choice would not establish the required idempotent retry repair decision.