Microsoft DP-900 Practice Test 87
Question 860
A sensor goes inactive and later resumes after a long gap. What is the MOST appropriate next validation or correction?
- Test click streams with gaps shorter and longer than timeout.
- Reconstruct sample fact lineage across each pipeline step.
- Treat every event received in the same calendar day as one continuous session.
- Test delayed events around an aggregation boundary.
Explanation
Correct Answer
A:Test click streams with gaps shorter and longer than timeout. This tests the intended result: separate bursts form distinct sessions after gaps exceed policy.
Incorrect Answers
B:Reconstruct sample fact lineage across each pipeline step. It tests Data governance and lineage for analytics rather than the critical Session windows of event activity behavior. Session windows depend on activity gaps rather than rigid wall-clock buckets.
C:Treat every event received in the same calendar day as one continuous session. This unsafe shortcut leaves the Session windows of event activity problem unresolved. Fixed tumbling windows can split an active session at arbitrary boundaries.
D:Test delayed events around an aggregation boundary. It tests Event time versus processing time rather than the critical Session windows of event activity behavior. Session windows depend on activity gaps rather than rigid wall-clock buckets.
Question 861
A contact record has no KnownMiddleName value. After selecting the proper NULL and three-valued logic approach, which observation gives the clearest evidence of success?
- Authorized identities connect within assigned privileges and revoked users fail.
- Only groups whose computed total crosses the threshold remain.
- Missing values are included or excluded as business rules specify.
- A supported failover maintains service within documented expectations.
Explanation
Correct Answer
C:Missing values are included or excluded as business rules specify. This is the directly observable result for NULL and three-valued logic; sQL NULL represents absent or unknown values and ordinary equality does not match it.
Incorrect Answers
A:Authorized identities connect within assigned privileges and revoked users fail. This supports Azure SQL authentication and Entra identity, not confirmation of NULL and three-valued logic. The relevant evidence is that missing values are included or excluded as business rules specify.
B:Only groups whose computed total crosses the threshold remain. This supports SQL HAVING after grouping, not confirmation of NULL and three-valued logic. The relevant evidence is that missing values are included or excluded as business rules specify.
D:A supported failover maintains service within documented expectations. This supports Azure SQL high availability and zone resiliency, not confirmation of NULL and three-valued logic. The relevant evidence is that missing values are included or excluded as business rules specify.
Question 862
Data engineers need repeatable notebooks for a cleansing workflow. If the relevant Databricks collaborative notebooks safeguard is skipped, which failure is MOST directly associated with that omission?
- Failing to archive selected events loses history after retention.
- Expecting a notebook file alone to execute a cluster without compute is incorrect.
- Untracked library updates can make a previous transformation nonreproducible.
- Using overlapping hopping windows can count an event in several summaries.
Explanation
Correct Answer
C:Untracked library updates can make a previous transformation nonreproducible. Notebooks can combine code documentation and analytical results but require governed execution. A suitable check is to run notebook as an unattended job with fixed inputs.
Incorrect Answers
A:Failing to archive selected events loses history after retention. This failure is associated with Stream retention and historical analytics; it is not the primary failure in the stated Databricks collaborative notebooks scenario. Notebooks can combine code documentation and analytical results but require governed execution.
B:Expecting a notebook file alone to execute a cluster without compute is incorrect. This failure is associated with Azure Databricks Apache Spark processing; it is not the primary failure in the stated Databricks collaborative notebooks scenario. Notebooks can combine code documentation and analytical results but require governed execution.
D:Using overlapping hopping windows can count an event in several summaries. This failure is associated with Tumbling time windows; it is not the primary failure in the stated Databricks collaborative notebooks scenario. Notebooks can combine code documentation and analytical results but require governed execution.
Question 863
A company wants managed backups without migrating to the SQL Server engine. Which principle BEST explains the correct Azure Database for PostgreSQL managed service design decision?
- Cosmos DB supports distributed data models but partition and consistency choices matter.
- DBAs manage database reliability security and recoverability within their responsibility boundary.
- PostgreSQL-managed Azure service preserves PostgreSQL engine semantics rather than T-SQL engine identity.
- Analytical history and mutable operational attributes have different retention semantics.
Explanation
Correct Answer
C:PostgreSQL-managed Azure service preserves PostgreSQL engine semantics rather than T-SQL engine identity. In this case the applicable decision is to select Azure Database for PostgreSQL Flexible Server where compatible.
Incorrect Answers
A:Cosmos DB supports distributed data models but partition and consistency choices matter. That concept explains Cosmos DB for distributed JSON apps; the situation instead concerns Azure Database for PostgreSQL managed service. Assuming PostgreSQL is Azure SQL Database may break client drivers or functions.
B:DBAs manage database reliability security and recoverability within their responsibility boundary. That concept explains DBA backup and recovery responsibility; the situation instead concerns Azure Database for PostgreSQL managed service. Assuming PostgreSQL is Azure SQL Database may break client drivers or functions.
D:Analytical history and mutable operational attributes have different retention semantics. That concept explains Historical dimensions versus current operational truth; the situation instead concerns Azure Database for PostgreSQL managed service. Assuming PostgreSQL is Azure SQL Database may break client drivers or functions.
Question 864
Administrators need managed SQL while retaining broad SQL Server instance features. What is the MOST appropriate next validation or correction?
- Validate subnet DNS firewall and client access.
- Assume Azure SQL Managed Instance gives root access to its underlying operating system.
- Inventory SQL Agent jobs linked servers and supported features before migration.
- Test missing-parent inserts and deletion cases under the actual constraint.
Explanation
Correct Answer
C:Inventory SQL Agent jobs linked servers and supported features before migration. This tests the intended result: required instance features work subject to documented compatibility and service limits.
Incorrect Answers
A:Validate subnet DNS firewall and client access. It tests SQL Managed Instance virtual network rather than the critical Azure SQL Managed Instance compatibility behavior. SQL Managed Instance provides more instance-level SQL Server compatibility than a single Azure SQL database.
B:Assume Azure SQL Managed Instance gives root access to its underlying operating system. This unsafe shortcut leaves the Azure SQL Managed Instance compatibility problem unresolved. Blindly moving instance-specific code to Azure SQL Database can fail.
D:Test missing-parent inserts and deletion cases under the actual constraint. It tests Foreign key referential integrity rather than the critical Azure SQL Managed Instance compatibility behavior. SQL Managed Instance provides more instance-level SQL Server compatibility than a single Azure SQL database.
Question 865
A social application asks for multi-hop friend graph traversals. Select TWO statements that correctly describe the Cosmos DB API for Apache Gremlin graph implementation and how it can be verified.
- Use an Azure Table RowKey as a complete replacement for Gremlin traversals.
- Use block blobs and their supported block upload/commit operations.
- Use Cosmos DB for Apache Gremlin for suitable graph vertices edges and traversals.
- Compare supported serverless and provisioned RU throughput for workload pattern.
- Graph queries follow intended relationship paths and return connected entities.
Explanation
Correct Answers
C:Use Cosmos DB for Apache Gremlin for suitable graph vertices edges and traversals. This is an appropriate action for the Cosmos DB API for Apache Gremlin graph case. Gremlin API models relationships as vertices and edges.
E:Graph queries follow intended relationship paths and return connected entities. This is directly observable success evidence for Cosmos DB API for Apache Gremlin graph.
Incorrect Answers
A:Use an Azure Table RowKey as a complete replacement for Gremlin traversals. This is not a safe or appropriate Cosmos DB API for Apache Gremlin graph implementation. Flattening graph traversal into independent key point reads may be awkward.
B:Use block blobs and their supported block upload/commit operations. This implements Block blob file uploads instead of the required Cosmos DB API for Apache Gremlin graph function. Gremlin API models relationships as vertices and edges.
D:Compare supported serverless and provisioned RU throughput for workload pattern. This implements Cosmos DB serverless versus provisioned throughput instead of the required Cosmos DB API for Apache Gremlin graph function. Gremlin API models relationships as vertices and edges.
Question 866
A payroll pipeline processes approved files once each night. If the relevant Batch scheduled processing safeguard is skipped, which failure is MOST directly associated with that omission?
- Treating a typed column as arbitrary free text undermines comparison and validation.
- High throughput alone cannot guarantee a low p99 request latency.
- Giving every reader db_owner increases accidental and malicious impact.
- Lack of idempotency can duplicate rows on rerun.
Explanation
Correct Answer
D:Lack of idempotency can duplicate rows on rerun. Batch work processes bounded collections at selected times. A suitable check is to replay a failed batch and compare source and destination counts.
Incorrect Answers
A:Treating a typed column as arbitrary free text undermines comparison and validation. This failure is associated with Structured records in a customer table; it is not the primary failure in the stated Batch scheduled processing scenario. Batch work processes bounded collections at selected times.
B:High throughput alone cannot guarantee a low p99 request latency. This failure is associated with Operational SLA latency versus throughput; it is not the primary failure in the stated Batch scheduled processing scenario. Batch work processes bounded collections at selected times.
C:Giving every reader db_owner increases accidental and malicious impact. This failure is associated with DBA least privilege account roles; it is not the primary failure in the stated Batch scheduled processing scenario. Batch work processes bounded collections at selected times.
Question 867
A team wants each event counted in exactly one fixed five-minute bucket. During testing, the team observes this specific failure: Using overlapping hopping windows can count an event in several summaries. Which corrective check should be performed FIRST?
- Configure an eligible OneLake shortcut and access to its target.
- Test events at minute boundaries and compare bucket counts.
- Persist consumer checkpoints and design idempotent downstream handling.
- Create a row for each second and call it a five-minute tumbling window.
Explanation
Correct Answer
B:Test events at minute boundaries and compare bucket counts. A successful correction should demonstrate that events are assigned to nonoverlapping fixed-duration windows.
Incorrect Answers
A:Configure an eligible OneLake shortcut and access to its target. It serves OneLake shortcut referencing existing data, not the diagnosed Tumbling time windows problem. Using overlapping hopping windows can count an event in several summaries.
C:Persist consumer checkpoints and design idempotent downstream handling. It serves Streaming checkpoints and replay, not the diagnosed Tumbling time windows problem. Using overlapping hopping windows can count an event in several summaries.
D:Create a row for each second and call it a five-minute tumbling window. This reinforces the error rather than addressing the Tumbling time windows failure. Tumbling windows have contiguous nonoverlapping time intervals.
Question 868
A project stores media files shared spreadsheets and device metadata. Which choice BEST meets this requirement?
- Call all three services SQL relational databases because they belong to Azure Storage.
- Configure Azure Files SMB shares and appropriate network and identity permissions.
- Match Blob for objects Files for file shares and Table for simple key-value entities.
- Choose a partition key with sufficient cardinality and even request distribution.
Explanation
Correct Answer
C:Azure Storage services expose distinct data models even within one storage account.
Incorrect Answers
A:Call all three services SQL relational databases because they belong to Azure Storage. It does not implement Choosing Blob Files and Table for app needs. One universal interface assumption leads to unsupported operations.
B:Configure Azure Files SMB shares and appropriate network and identity permissions. That action primarily handles Azure Files SMB application migration; the given requirement is Choosing Blob Files and Table for app needs. Azure Storage services expose distinct data models even within one storage account.
D:Choose a partition key with sufficient cardinality and even request distribution. That action primarily handles Cosmos DB logical partition key; the given requirement is Choosing Blob Files and Table for app needs. Azure Storage services expose distinct data models even within one storage account.
Question 869
A fraud report needs customers whose aggregate annual spend exceeds a limit. If the relevant SQL HAVING after grouping safeguard is skipped, which failure is MOST directly associated with that omission?
- Filtering individual rows cannot replace a condition on group totals.
- An Entra login by itself does not grant access to every table.
- Assuming views automatically encrypt their base tables misstates access protection.
- Assuming the app's schema is automatically redesigned causes migration surprises.
Explanation
Correct Answer
A:Filtering individual rows cannot replace a condition on group totals. HAVING filters aggregated groups while WHERE filters source rows. A suitable check is to test a group with many small charges whose total exceeds threshold.
Incorrect Answers
B:An Entra login by itself does not grant access to every table. This failure is associated with Azure SQL authentication and Entra identity; it is not the primary failure in the stated SQL HAVING after grouping scenario. HAVING filters aggregated groups while WHERE filters source rows.
C:Assuming views automatically encrypt their base tables misstates access protection. This failure is associated with SQL view virtual query object; it is not the primary failure in the stated SQL HAVING after grouping scenario. HAVING filters aggregated groups while WHERE filters source rows.
D:Assuming the app's schema is automatically redesigned causes migration surprises. This failure is associated with Azure SQL Database single database PaaS; it is not the primary failure in the stated SQL HAVING after grouping scenario. HAVING filters aggregated groups while WHERE filters source rows.
Question 870
A report needs to find one phone number without parsing a free-form list. Select TWO statements that correctly describe the First normal form atomic attributes implementation and how it can be verified.
- Separate repeated multivalued attributes into appropriately related rows.
- Each value can be queried and validated without splitting a cell.
- Rename a comma list Email1 and declare it atomic.
- Apply a UNIQUE constraint or index on the additional business key.
- Verify managed TDE at-rest behavior and independently enforce secure connection settings.
Explanation
Correct Answers
A:Separate repeated multivalued attributes into appropriately related rows. This is an appropriate action for the First normal form atomic attributes case. First normal form favors atomic values in relational columns.
B:Each value can be queried and validated without splitting a cell. This is directly observable success evidence for First normal form atomic attributes.
Incorrect Answers
C:Rename a comma list Email1 and declare it atomic. This is not a safe or appropriate First normal form atomic attributes implementation. Packing many values into one column creates update and search anomalies.
D:Apply a UNIQUE constraint or index on the additional business key. This implements Unique index versus primary key instead of the required First normal form atomic attributes function. First normal form favors atomic values in relational columns.
E:Verify managed TDE at-rest behavior and independently enforce secure connection settings. This implements Transparent data encryption versus query TLS instead of the required First normal form atomic attributes function. First normal form favors atomic values in relational columns.