Microsoft DP-900 Practice Test 40
Question 390
A mobile app emits orders with common keys but occasional optional delivery instructions. If the relevant Semi structured JSON documents safeguard is skipped, which failure is MOST directly associated with that omission?
- Deferring all validation for payment records can admit unusable transactions.
- Calling a trend description a proven cause can mislead decisions.
- Assuming every JSON object has a fixed relational schema causes null errors and brittle ingestion.
- A pipeline that merely completes does not prove data correctness.
Explanation
Correct Answer
C:Assuming every JSON object has a fixed relational schema causes null errors and brittle ingestion. Semi structured data has organizational markers without requiring identical columns in every record. A suitable check is to validate sample nested documents and implement optional-field handling.
Incorrect Answers
A:Deferring all validation for payment records can admit unusable transactions. This failure is associated with Schema-on-read versus schema-on-write; it is not the primary failure in the stated Semi structured JSON documents scenario. Semi structured data has organizational markers without requiring identical columns in every record.
B:Calling a trend description a proven cause can mislead decisions. This failure is associated with Descriptive versus diagnostic analytics; it is not the primary failure in the stated Semi structured JSON documents scenario. Semi structured data has organizational markers without requiring identical columns in every record.
D:A pipeline that merely completes does not prove data correctness. This failure is associated with Data quality completeness and accuracy; it is not the primary failure in the stated Semi structured JSON documents scenario. Semi structured data has organizational markers without requiring identical columns in every record.
Question 391
A distributor knows forecast demand and must decide depot allocations. Which choice BEST meets this requirement?
- Implement schema validation evolution and compatibility checks in ingestion.
- Treat a probability forecast as an executable truck routing instruction.
- Fit an appropriately validated forecasting or classification model on relevant data.
- Use an optimization or decision model to compare feasible actions.
Explanation
Correct Answer
D:Prescriptive analytics recommends actions rather than simply predicting values.
Incorrect Answers
A:Implement schema validation evolution and compatibility checks in ingestion. That action primarily handles Data engineer schema and format changes; the given requirement is Prescriptive decision optimization. Prescriptive analytics recommends actions rather than simply predicting values.
B:Treat a probability forecast as an executable truck routing instruction. It does not implement Prescriptive decision optimization. An unconstrained optimizer may propose impossible schedules.
C:Fit an appropriately validated forecasting or classification model on relevant data. That action primarily handles Predictive analytics forecasts; the given requirement is Prescriptive decision optimization. Prescriptive analytics recommends actions rather than simply predicting values.
Question 392
New firmware adds a batteryHealth property to only some devices. What is the MOST appropriate next validation or correction?
- Test overwrites and restoration from the recorded version.
- Declare every entity invalid unless it matches a manually invented relational SQL schema.
- Test nested JSON access versus relational join constraints.
- Validate entities with missing versus null optional properties.
Explanation
Correct Answer
D:Validate entities with missing versus null optional properties. This tests the intended result: new and old devices can be read without demanding identical property sets.
Incorrect Answers
A:Test overwrites and restoration from the recorded version. It tests Blob versioning on overwrite rather than the critical Table Storage schemaless properties behavior. Azure Table Storage supports nonrelational wide entities beyond fixed SQL columns.
B:Declare every entity invalid unless it matches a manually invented relational SQL schema. This unsafe shortcut leaves the Table Storage schemaless properties problem unresolved. Assuming every entity has all optional fields causes parsing failures.
C:Test nested JSON access versus relational join constraints. It tests Cosmos DB API for NoSQL versus SQL text rather than the critical Table Storage schemaless properties behavior. Azure Table Storage supports nonrelational wide entities beyond fixed SQL columns.
Question 393
A retail dashboard reports that orders fell by 12 percent. Which choice BEST meets this requirement?
- Run a scheduled batch ingestion with clear checkpoints and retries.
- Assume a bar chart proves the causal effect of every category label.
- Choose Azure Database for MySQL Flexible Server for supported MySQL workloads.
- Separate descriptive measurement from diagnostic analysis of contributing factors.
Explanation
Correct Answer
D:Separate descriptive measurement from diagnostic analysis of contributing factors. Descriptive analytics summarizes history; diagnostic analytics explores causes. In the stated case, verification should show that one report states what happened while another tests why.
Incorrect Answers
A:Run a scheduled batch ingestion with clear checkpoints and retries. That action primarily handles Batch scheduled processing; the given requirement is Descriptive versus diagnostic analytics. Descriptive analytics summarizes history; diagnostic analytics explores causes.
B:Assume a bar chart proves the causal effect of every category label. It does not implement Descriptive versus diagnostic analytics. Calling a trend description a proven cause can mislead decisions.
C:Choose Azure Database for MySQL Flexible Server for supported MySQL workloads. That action primarily handles Azure MySQL versus PostgreSQL service-model selection; the given requirement is Descriptive versus diagnostic analytics. Descriptive analytics summarizes history; diagnostic analytics explores causes.
Question 394
Industrial sensors need identities for authenticated device-to-cloud telemetry. After selecting the proper Azure IoT Hub device messaging approach, which observation gives the clearest evidence of success?
- Approved device identities send telemetry while revoked devices are rejected.
- Intended filtered events appear at the configured downstream consumers.
- Curated rows use consistent codes while malformed rows are quarantined.
- Supported Spark and SQL experiences access the intended lakehouse tables.
Explanation
Correct Answer
A:Approved device identities send telemetry while revoked devices are rejected. This is the directly observable result for Azure IoT Hub device messaging; ioT Hub adds device management and identities around IoT messages.
Incorrect Answers
B:Intended filtered events appear at the configured downstream consumers. This supports Fabric Eventstreams real-time routing, not confirmation of Azure IoT Hub device messaging. The relevant evidence is that approved device identities send telemetry while revoked devices are rejected.
C:Curated rows use consistent codes while malformed rows are quarantined. This supports Batch ETL staging and cleansing, not confirmation of Azure IoT Hub device messaging. The relevant evidence is that approved device identities send telemetry while revoked devices are rejected.
D:Supported Spark and SQL experiences access the intended lakehouse tables. This supports Fabric Lakehouse managed tables and files, not confirmation of Azure IoT Hub device messaging. The relevant evidence is that approved device identities send telemetry while revoked devices are rejected.
Question 395
A team expects a partition-key lookup to find every synonym across product text. During testing, the team observes this specific failure: Assuming every document database query automatically provides relevance ranking can disappoint users. Which corrective check should be performed FIRST?
- Fit an appropriately validated forecasting or classification model on relevant data.
- Use an analytical warehouse or Fabric Warehouse for governed relational reporting.
- Compare exact-ID lookups with text-search queries and relevance.
- Use a customer ID hash as a natural-language semantic ranking index.
Explanation
Correct Answer
C:Compare exact-ID lookups with text-search queries and relevance. A successful correction should demonstrate that searches find relevant content while record reads remain reliable.
Incorrect Answers
A:Fit an appropriately validated forecasting or classification model on relevant data. It serves Predictive analytics forecasts, not the diagnosed Document indexing versus full-text search problem. Assuming every document database query automatically provides relevance ranking can disappoint users.
B:Use an analytical warehouse or Fabric Warehouse for governed relational reporting. It serves Analytical warehouse for structured reporting, not the diagnosed Document indexing versus full-text search problem. Assuming every document database query automatically provides relevance ranking can disappoint users.
D:Use a customer ID hash as a natural-language semantic ranking index. This reinforces the error rather than addressing the Document indexing versus full-text search failure. Point lookups and lexical text retrieval use different indexing models.
Question 396
Developers want to understand why cross-partition reads cost more than ID point reads. Select TWO statements that correctly describe the Cosmos DB Request Unit RU accounting implementation and how it can be verified.
- RU charge metrics explain cost and throttling for representative requests.
- Configure supported Azure Files snapshot or backup protection.
- Measure and budget provisioned or consumed request units for actual Cosmos operations.
- Evaluate multi-region writes with a deliberate conflict resolution policy.
- Assume a single SELECT query always consumes exactly one request unit.
Explanation
Correct Answers
A:RU charge metrics explain cost and throttling for representative requests. This is directly observable success evidence for Cosmos DB Request Unit RU accounting.
C:Measure and budget provisioned or consumed request units for actual Cosmos operations. This is an appropriate action for the Cosmos DB Request Unit RU accounting case. Cosmos DB measures resource consumption in request units rather than only raw data size.
Incorrect Answers
B:Configure supported Azure Files snapshot or backup protection. This implements Azure Files snapshots and backups instead of the required Cosmos DB Request Unit RU accounting function. Cosmos DB measures resource consumption in request units rather than only raw data size.
D:Evaluate multi-region writes with a deliberate conflict resolution policy. This implements Cosmos DB multi-region writes conflict handling instead of the required Cosmos DB Request Unit RU accounting function. Cosmos DB measures resource consumption in request units rather than only raw data size.
E:Assume a single SELECT query always consumes exactly one request unit. This is not a safe or appropriate Cosmos DB Request Unit RU accounting implementation. Treating every query as equal-cost can overload provisioned throughput.
Question 397
A catalog API adds nested attributes that differ between product categories. During testing, the team observes this specific failure: Assuming every JSON object has a fixed relational schema causes null errors and brittle ingestion. Which corrective check should be performed FIRST?
- Use a hierarchical-namespace enabled storage account for data lake file organization.
- Validate sample nested documents and implement optional-field handling.
- Normalize event instants with timezone offsets and retain needed locale context.
- Treat valid JSON syntax as proof every property has the same business meaning.
Explanation
Correct Answer
B:Validate sample nested documents and implement optional-field handling. A successful correction should demonstrate that consumers can read core fields and safely handle absent optional keys.
Incorrect Answers
A:Use a hierarchical-namespace enabled storage account for data lake file organization. It serves Azure Data Lake Storage Gen2 analytics landing, not the diagnosed Semi structured JSON documents problem. Assuming every JSON object has a fixed relational schema causes null errors and brittle ingestion.
C:Normalize event instants with timezone offsets and retain needed locale context. It serves Timestamp and timezone representation, not the diagnosed Semi structured JSON documents problem. Assuming every JSON object has a fixed relational schema causes null errors and brittle ingestion.
D:Treat valid JSON syntax as proof every property has the same business meaning. This reinforces the error rather than addressing the Semi structured JSON documents failure. Semi structured data has organizational markers without requiring identical columns in every record.
Question 398
A warehouse tracks inventory quantity per ProductID and WarehouseID. Which choice BEST meets this requirement?
- Use a composite key over the product and location identifiers.
- Choose supported Azure SQL geo-replication or failover groups with realistic RPO/RTO.
- Treat a composite key as two unrelated unique single-column constraints.
- Use GROUP BY then HAVING to filter aggregate group results.
Explanation
Correct Answer
A:A composite primary key identifies rows using multiple columns.
Incorrect Answers
B:Choose supported Azure SQL geo-replication or failover groups with realistic RPO/RTO. That action primarily handles Azure SQL active geo-replication tradeoff; the given requirement is Composite primary key association. A composite primary key identifies rows using multiple columns.
C:Treat a composite key as two unrelated unique single-column constraints. It does not implement Composite primary key association. Indexing only ProductID would incorrectly forbid the same product in multiple warehouses.
D:Use GROUP BY then HAVING to filter aggregate group results. That action primarily handles SQL HAVING after grouping; the given requirement is Composite primary key association. A composite primary key identifies rows using multiple columns.
Question 399
A file-based analytics table is corrupted by partial append attempts. Which principle BEST explains the correct Delta Lake transactional table metadata design decision?
- Power BI Desktop is an authoring tool for data modeling and reports.
- Delta tables add transactional metadata and versioning on lake files.
- Incremental load avoids repeated full snapshots while demanding consistent checkpoints.
- Eventhouse is optimized for event and time-series analytical workloads.
Explanation
Correct Answer
B:Delta tables add transactional metadata and versioning on lake files. In this case the applicable decision is to use Delta Lake table semantics with supported transaction logs where appropriate.
Incorrect Answers
A:Power BI Desktop is an authoring tool for data modeling and reports. That concept explains Power BI Desktop data import; the situation instead concerns Delta Lake transactional table metadata. Treating loose Parquet files as transactional Delta tables can expose partial results.
C:Incremental load avoids repeated full snapshots while demanding consistent checkpoints. That concept explains Incremental ingestion with watermark; the situation instead concerns Delta Lake transactional table metadata. Treating loose Parquet files as transactional Delta tables can expose partial results.
D:Eventhouse is optimized for event and time-series analytical workloads. That concept explains Fabric Eventhouse KQL event analytics; the situation instead concerns Delta Lake transactional table metadata. Treating loose Parquet files as transactional Delta tables can expose partial results.
Question 400
A team publishes an interactive multi-page analytical report to coworkers. Which principle BEST explains the correct Power BI reports dashboards and sharing design decision?
- Real-Time hub is a discovery and access experience for data in motion.
- IoT Hub adds device management and identities around IoT messages.
- Reports and dashboards have different presentation and interaction roles.
- Cards emphasize one important measure rather than complex multivariate trends.
Explanation
Correct Answer
C:Reports and dashboards have different presentation and interaction roles. In this case the applicable decision is to distinguish multi-page reports from service dashboards and share through correct workspace/app policy.
Incorrect Answers
A:Real-Time hub is a discovery and access experience for data in motion. That concept explains Fabric Real-Time hub stream discovery; the situation instead concerns Power BI reports dashboards and sharing. Sharing one report URL does not automatically authorize every underlying data source.
B:IoT Hub adds device management and identities around IoT messages. That concept explains Azure IoT Hub device messaging; the situation instead concerns Power BI reports dashboards and sharing. Sharing one report URL does not automatically authorize every underlying data source.
D:Cards emphasize one important measure rather than complex multivariate trends. That concept explains KPI card single metric; the situation instead concerns Power BI reports dashboards and sharing. Sharing one report URL does not automatically authorize every underlying data source.