Microsoft DP-900 Practice Test 84
Question 830
A designer must add a new decimal column to an existing schema. Which choice BEST meets this requirement?
- Use SQL Server on an Azure VM when full guest and engine control is required.
- Use SELECT to add a permanent database column.
- Model the association with a bridge table holding the two parent keys.
- Use CREATE or ALTER as appropriate for relational schema changes.
Explanation
Correct Answer
D:Use CREATE or ALTER as appropriate for relational schema changes. Data definition language defines database objects and structure. In the stated case, verification should show that table definitions change while intended existing business rows remain recoverable.
Incorrect Answers
A:Use SQL Server on an Azure VM when full guest and engine control is required. That action primarily handles SQL Server on Azure VM OS control; the given requirement is CREATE ALTER DROP DDL. Data definition language defines database objects and structure.
B:Use SELECT to add a permanent database column. It does not implement CREATE ALTER DROP DDL. Dropping a table destroys its object rather than merely hiding a field.
C:Model the association with a bridge table holding the two parent keys. That action primarily handles Many to many bridge table; the given requirement is CREATE ALTER DROP DDL. Data definition language defines database objects and structure.
Question 831
An application expects all events for one customer to retain a useful relative order. Which principle BEST explains the correct Event streams partitioning and key order design decision?
- Lakehouse combines files and tables for mixed analytical workloads.
- Session windows depend on activity gaps rather than rigid wall-clock buckets.
- Power BI Desktop is an authoring tool for data modeling and reports.
- Partitioned streaming distributes throughput but global ordering is not guaranteed.
Explanation
Correct Answer
D:Partitioned streaming distributes throughput but global ordering is not guaranteed. In this case the applicable decision is to partition events by suitable key and document ordering constraints.
Incorrect Answers
A:Lakehouse combines files and tables for mixed analytical workloads. That concept explains Fabric Lakehouse managed tables and files; the situation instead concerns Event streams partitioning and key order. Assuming order across unrelated partitions can corrupt sequence reconstruction.
B:Session windows depend on activity gaps rather than rigid wall-clock buckets. That concept explains Session windows of event activity; the situation instead concerns Event streams partitioning and key order. Assuming order across unrelated partitions can corrupt sequence reconstruction.
C:Power BI Desktop is an authoring tool for data modeling and reports. That concept explains Power BI Desktop data import; the situation instead concerns Event streams partitioning and key order. Assuming order across unrelated partitions can corrupt sequence reconstruction.
Question 832
Batch transformations exceed capacity of a single local script. Select TWO statements that correctly describe the Azure Databricks Apache Spark processing implementation and how it can be verified.
- Rename a Python list spark and assume calculations distribute automatically.
- Distributed transformations produce correct partitions and aggregated outputs.
- Distinguish multi-page reports from service dashboards and share through correct workspace/app policy.
- Use Azure Databricks with suitable Spark compute and governed data access.
- Use OneLake as the shared logical data-lake foundation for supported Fabric workloads.
Explanation
Correct Answers
B:Distributed transformations produce correct partitions and aggregated outputs. This is directly observable success evidence for Azure Databricks Apache Spark processing.
D:Use Azure Databricks with suitable Spark compute and governed data access. This is an appropriate action for the Azure Databricks Apache Spark processing case. Spark processes distributed datasets in parallel across compute workers.
Incorrect Answers
A:Rename a Python list spark and assume calculations distribute automatically. This is not a safe or appropriate Azure Databricks Apache Spark processing implementation. Expecting a notebook file alone to execute a cluster without compute is incorrect.
C:Distinguish multi-page reports from service dashboards and share through correct workspace/app policy. This implements Power BI reports dashboards and sharing instead of the required Azure Databricks Apache Spark processing function. Spark processes distributed datasets in parallel across compute workers.
E:Use OneLake as the shared logical data-lake foundation for supported Fabric workloads. This implements Microsoft Fabric OneLake unified storage instead of the required Azure Databricks Apache Spark processing function. Spark processes distributed datasets in parallel across compute workers.
Question 833
Industrial sensors need identities for authenticated device-to-cloud telemetry. Which choice BEST meets this requirement?
- Use inactivity-based session windows to group related event sequences.
- Use a CSV filename as an IoT device authentication credential.
- Choose Azure IoT Hub for supported device-oriented connectivity and management.
- Track source lineage transformation runs ownership and curated output metadata.
Explanation
Correct Answer
C:IoT Hub adds device management and identities around IoT messages.
Incorrect Answers
A:Use inactivity-based session windows to group related event sequences. That action primarily handles Session windows of event activity; the given requirement is Azure IoT Hub device messaging. IoT Hub adds device management and identities around IoT messages.
B:Use a CSV filename as an IoT device authentication credential. It does not implement Azure IoT Hub device messaging. A generic anonymous event endpoint may not satisfy per-device identity policies.
D:Track source lineage transformation runs ownership and curated output metadata. That action primarily handles Data governance and lineage for analytics; the given requirement is Azure IoT Hub device messaging. IoT Hub adds device management and identities around IoT messages.
Question 834
Administrators need managed SQL while retaining broad SQL Server instance features. Select TWO statements that correctly describe the Azure SQL Managed Instance compatibility implementation and how it can be verified.
- Evaluate Azure SQL Managed Instance for compatible lift-and-modernize workloads.
- Required instance features work subject to documented compatibility and service limits.
- Assume Azure SQL Managed Instance gives root access to its underlying operating system.
- Choose Azure SQL Database and size the individual database compute tier.
- Denormalize only selected analytical attributes with a refresh consistency plan.
Explanation
Correct Answers
A:Evaluate Azure SQL Managed Instance for compatible lift-and-modernize workloads. This is an appropriate action for the Azure SQL Managed Instance compatibility case. SQL Managed Instance provides more instance-level SQL Server compatibility than a single Azure SQL database.
B:Required instance features work subject to documented compatibility and service limits. This is directly observable success evidence for Azure SQL Managed Instance compatibility.
Incorrect Answers
C:Assume Azure SQL Managed Instance gives root access to its underlying operating system. This is not a safe or appropriate Azure SQL Managed Instance compatibility implementation. Blindly moving instance-specific code to Azure SQL Database can fail.
D:Choose Azure SQL Database and size the individual database compute tier. This implements Azure SQL Database single database PaaS instead of the required Azure SQL Managed Instance compatibility function. SQL Managed Instance provides more instance-level SQL Server compatibility than a single Azure SQL database.
E:Denormalize only selected analytical attributes with a refresh consistency plan. This implements Denormalization for analytics tradeoff instead of the required Azure SQL Managed Instance compatibility function. SQL Managed Instance provides more instance-level SQL Server compatibility than a single Azure SQL database.
Question 835
A designer considers a pie chart for hundreds of daily measurements. Which principle BEST explains the correct Line chart time-series selection design decision?
- Slicers provide user-driven data filtering rather than changing source rows.
- Lakehouse combines files and tables for mixed analytical workloads.
- Line charts effectively show change across time.
- Real-Time hub is a discovery and access experience for data in motion.
Explanation
Correct Answer
C:Line charts effectively show change across time. In this case the applicable decision is to use a line chart with a continuous or properly sorted time axis.
Incorrect Answers
A:Slicers provide user-driven data filtering rather than changing source rows. That concept explains Slicer interactive filter; the situation instead concerns Line chart time-series selection. Treating dates as unordered labels can scramble a trend.
B:Lakehouse combines files and tables for mixed analytical workloads. That concept explains Fabric Lakehouse managed tables and files; the situation instead concerns Line chart time-series selection. Treating dates as unordered labels can scramble a trend.
D: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 Line chart time-series selection. Treating dates as unordered labels can scramble a trend.
Question 836
Multiple VMs need to access documents through SMB rather than a Blob REST API. During testing, the team observes this specific failure: Replacing SMB mounts with blob URLs without application changes breaks path expectations. Which corrective check should be performed FIRST?
- Use a supported retry-after/backoff strategy and scale throughput if justified.
- Issue a limited SAS or supported delegated access scoped by operation resource and expiry.
- Assume choosing a Blob container creates an SMB share automatically.
- Test UNC mounting permissions and file operations.
Explanation
Correct Answer
D:Test UNC mounting permissions and file operations. A successful correction should demonstrate that supported clients mount the share and read or write approved paths.
Incorrect Answers
A:Use a supported retry-after/backoff strategy and scale throughput if justified. It serves Cosmos DB 429 throttling retries, not the diagnosed Azure Files SMB application migration problem. Replacing SMB mounts with blob URLs without application changes breaks path expectations.
B:Issue a limited SAS or supported delegated access scoped by operation resource and expiry. It serves Blob SAS delegated access, not the diagnosed Azure Files SMB application migration problem. Replacing SMB mounts with blob URLs without application changes breaks path expectations.
C:Assume choosing a Blob container creates an SMB share automatically. This reinforces the error rather than addressing the Azure Files SMB application migration failure. Azure Files provides managed shared file access distinct from object Blob access.
Question 837
A server emits free-form diagnostics and a separate JSON event for each request. After selecting the proper Log text extraction versus structured event fields approach, which observation gives the clearest evidence of success?
- Users move from aggregate to detail with correct filter behavior.
- Queries read relevant columns efficiently while preserving typed values.
- Aggregates group actual status codes rather than arbitrary matching text.
- Both changes commit or neither change remains partially recorded.
Explanation
Correct Answer
C:Aggregates group actual status codes rather than arbitrary matching text. This is the directly observable result for Log text extraction versus structured event fields; unstructured logs can become analyzable after parsing but remain unstructured at source.
Incorrect Answers
A:Users move from aggregate to detail with correct filter behavior. This supports Data analyst slicing and drill-down, not confirmation of Log text extraction versus structured event fields. The relevant evidence is that aggregates group actual status codes rather than arbitrary matching text.
B:Queries read relevant columns efficiently while preserving typed values. This supports Parquet columnar analytical file, not confirmation of Log text extraction versus structured event fields. The relevant evidence is that aggregates group actual status codes rather than arbitrary matching text.
D:Both changes commit or neither change remains partially recorded. This supports OLTP atomic purchase transaction, not confirmation of Log text extraction versus structured event fields. The relevant evidence is that aggregates group actual status codes rather than arbitrary matching text.
Question 838
A lakehouse can ingest raw transactions and use SQL engines to clean them. Which choice BEST meets this requirement?
- Assume ELT means no transformations are needed.
- Define fact grain and descriptive dimension keys before analytical modelling.
- Ingest raw data then perform controlled ELT transformations within target compute.
- Choose Azure IoT Hub for supported device-oriented connectivity and management.
Explanation
Correct Answer
C:ELT loads before transformation and uses destination processing resources.
Incorrect Answers
A:Assume ELT means no transformations are needed. It does not implement ELT warehouse pushdown transforms. Dropping raw inputs before validating transforms harms reproducibility.
B:Define fact grain and descriptive dimension keys before analytical modelling. That action primarily handles Analytical fact and dimension grain; the given requirement is ELT warehouse pushdown transforms. ELT loads before transformation and uses destination processing resources.
D:Choose Azure IoT Hub for supported device-oriented connectivity and management. That action primarily handles Azure IoT Hub device messaging; the given requirement is ELT warehouse pushdown transforms. ELT loads before transformation and uses destination processing resources.
Question 839
A dataset contains many rows for each store but management wants one total per store. Which principle BEST explains the correct SQL GROUP BY aggregate design decision?
- GROUP BY organizes records into groups for aggregate calculations.
- A left outer join keeps all left-side rows even without right-side matches.
- Elastic pools support shared resource budgeting for multiple databases.
- Managed database backups support restore windows but still require planning and testing.
Explanation
Correct Answer
A:GROUP BY organizes records into groups for aggregate calculations. In this case the applicable decision is to use SUM with GROUP BY on the intended grouping columns.
Incorrect Answers
B:A left outer join keeps all left-side rows even without right-side matches. That concept explains Left outer join preserving parents; the situation instead concerns SQL GROUP BY aggregate. Selecting ungrouped detail fields can produce invalid or misleading results.
C:Elastic pools support shared resource budgeting for multiple databases. That concept explains Azure SQL elastic pool sharing; the situation instead concerns SQL GROUP BY aggregate. Selecting ungrouped detail fields can produce invalid or misleading results.
D:Managed database backups support restore windows but still require planning and testing. That concept explains Azure SQL Database backup PITR; the situation instead concerns SQL GROUP BY aggregate. Selecting ungrouped detail fields can produce invalid or misleading results.
Question 840
A data team wants to retain raw source snapshots before producing tables. Select TWO statements that correctly describe the ELT warehouse pushdown transforms implementation and how it can be verified.
- Ingest raw data then perform controlled ELT transformations within target compute.
- Model a central fact table and suitable date customer and product dimensions.
- Curated tables can be rebuilt from retained raw inputs.
- Store appropriate analytical data in Parquet columnar files.
- Assume ELT means no transformations are needed.
Explanation
Correct Answers
A:Ingest raw data then perform controlled ELT transformations within target compute. This is an appropriate action for the ELT warehouse pushdown transforms case. ELT loads before transformation and uses destination processing resources.
C:Curated tables can be rebuilt from retained raw inputs. This is directly observable success evidence for ELT warehouse pushdown transforms.
Incorrect Answers
B:Model a central fact table and suitable date customer and product dimensions. This implements Star schema report model instead of the required ELT warehouse pushdown transforms function. ELT loads before transformation and uses destination processing resources.
D:Store appropriate analytical data in Parquet columnar files. This implements Parquet compressed columnar analytics instead of the required ELT warehouse pushdown transforms function. ELT loads before transformation and uses destination processing resources.
E:Assume ELT means no transformations are needed. This is not a safe or appropriate ELT warehouse pushdown transforms implementation. Dropping raw inputs before validating transforms harms reproducibility.