Microsoft DP-900 Practice Test 50
Question 490
Slow SQL queries cause a billing application to time out. If the relevant DBA performance tuning and indexing safeguard is skipped, which failure is MOST directly associated with that omission?
- Adding random indexes can increase write cost without fixing the bottleneck.
- Assuming PostgreSQL is Azure SQL Database may break client drivers or functions.
- Silently dropping changed fields can produce inaccurate downstream analytics.
- Naively splitting on every comma corrupts quoted field values.
Explanation
Correct Answer
A:Adding random indexes can increase write cost without fixing the bottleneck. DBAs tune database performance as well as maintaining access and reliability. A suitable check is to compare query plans and before-after latency on test workloads.
Incorrect Answers
B:Assuming PostgreSQL is Azure SQL Database may break client drivers or functions. This failure is associated with Azure Database for PostgreSQL managed service; it is not the primary failure in the stated DBA performance tuning and indexing scenario. DBAs tune database performance as well as maintaining access and reliability.
C:Silently dropping changed fields can produce inaccurate downstream analytics. This failure is associated with Data engineer schema and format changes; it is not the primary failure in the stated DBA performance tuning and indexing scenario. DBAs tune database performance as well as maintaining access and reliability.
D:Naively splitting on every comma corrupts quoted field values. This failure is associated with CSV delimited text schema; it is not the primary failure in the stated DBA performance tuning and indexing scenario. DBAs tune database performance as well as maintaining access and reliability.
Question 491
A project combines Spark notebooks and SQL-based finance reporting. Which choice BEST meets this requirement?
- Compare Fabric Lakehouse and Warehouse according to engineering languages and query patterns.
- Configure an appropriate data gateway and scheduled refresh where needed.
- Use Delta Lake table semantics with supported transaction logs where appropriate.
- Assume Lakehouse and Warehouse are exactly identical because both use OneLake.
Explanation
Correct Answer
A:Fabric workloads have complementary analytics designs rather than one universal model.
Incorrect Answers
B:Configure an appropriate data gateway and scheduled refresh where needed. That action primarily handles Power BI scheduled refresh and gateway; the given requirement is Lakehouse versus Warehouse selection. Fabric workloads have complementary analytics designs rather than one universal model.
C:Use Delta Lake table semantics with supported transaction logs where appropriate. That action primarily handles Delta Lake transactional table metadata; the given requirement is Lakehouse versus Warehouse selection. Fabric workloads have complementary analytics designs rather than one universal model.
D:Assume Lakehouse and Warehouse are exactly identical because both use OneLake. It does not implement Lakehouse versus Warehouse selection. Picking a SQL-first store for raw notebook-only work may cause extra conversions.
Question 492
Order fact rows must connect to one Product dimension row. After selecting the proper One-to-many semantic relationships approach, which observation gives the clearest evidence of success?
- The engine scans relevant partitions rather than every archive folder.
- Filtered aggregations match approved transactional totals.
- Product filters affect intended fact rows without unpredictable double counting.
- Authorized users locate sources and their connections under governance.
Explanation
Correct Answer
C:Product filters affect intended fact rows without unpredictable double counting. This is the directly observable result for One-to-many semantic relationships; relationship cardinality controls how tables filter one another.
Incorrect Answers
A:The engine scans relevant partitions rather than every archive folder. This supports Data lake partition pruning, not confirmation of One-to-many semantic relationships. The relevant evidence is that product filters affect intended fact rows without unpredictable double counting.
B:Filtered aggregations match approved transactional totals. This supports Star schema report model, not confirmation of One-to-many semantic relationships. The relevant evidence is that product filters affect intended fact rows without unpredictable double counting.
D:Authorized users locate sources and their connections under governance. This supports Fabric Real-Time hub stream discovery, not confirmation of One-to-many semantic relationships. The relevant evidence is that product filters affect intended fact rows without unpredictable double counting.
Question 493
A monitoring team wants a notification after an error rate threshold is breached. If the relevant Fabric Activator rule-triggered action safeguard is skipped, which failure is MOST directly associated with that omission?
- Using a text-sorted MonthName without year context can misorder periods.
- Without a rule/action connection monitoring does not imply automatic response.
- Relying only on a visual slicer is not a security boundary.
- Assuming order across unrelated partitions can corrupt sequence reconstruction.
Explanation
Correct Answer
B:Without a rule/action connection monitoring does not imply automatic response. Activator turns detected data conditions into governed actions. A suitable check is to test both triggering and non-triggering input streams.
Incorrect Answers
A:Using a text-sorted MonthName without year context can misorder periods. This failure is associated with Drill-down hierarchy for time; it is not the primary failure in the stated Fabric Activator rule-triggered action scenario. Activator turns detected data conditions into governed actions.
C:Relying only on a visual slicer is not a security boundary. This failure is associated with Power BI row-level security RLS; it is not the primary failure in the stated Fabric Activator rule-triggered action scenario. Activator turns detected data conditions into governed actions.
D:Assuming order across unrelated partitions can corrupt sequence reconstruction. This failure is associated with Event streams partitioning and key order; it is not the primary failure in the stated Fabric Activator rule-triggered action scenario. Activator turns detected data conditions into governed actions.
Question 494
A report requires fast cached slicing but near-real-time updates may be needed. After selecting the proper Power BI Import versus DirectQuery mode approach, which observation gives the clearest evidence of success?
- Distributed transformations produce correct partitions and aggregated outputs.
- Separate user roles receive only their permitted data rows.
- Model refresh and source query behavior meet the business SLA.
- Supported Spark and SQL experiences access the intended lakehouse tables.
Explanation
Correct Answer
C:Model refresh and source query behavior meet the business SLA. This is the directly observable result for Power BI Import versus DirectQuery mode; import caches data while DirectQuery can query sources at interaction time.
Incorrect Answers
A:Distributed transformations produce correct partitions and aggregated outputs. This supports Azure Databricks Apache Spark processing, not confirmation of Power BI Import versus DirectQuery mode. The relevant evidence is that model refresh and source query behavior meet the business SLA.
B:Separate user roles receive only their permitted data rows. This supports Power BI row-level security RLS, not confirmation of Power BI Import versus DirectQuery mode. The relevant evidence is that model refresh and source query behavior meet the business SLA.
D:Supported Spark and SQL experiences access the intended lakehouse tables. This supports Fabric Lakehouse managed tables and files, not confirmation of Power BI Import versus DirectQuery mode. The relevant evidence is that model refresh and source query behavior meet the business SLA.
Question 495
Operations must recover a database to a point before a faulty deployment. Which principle BEST explains the correct Azure SQL Database backup PITR design decision?
- Database auditing provides evidence while database roles govern permissions.
- An inner join returns rows with a matching join condition.
- Managed database backups support restore windows but still require planning and testing.
- A left outer join keeps all left-side rows even without right-side matches.
Explanation
Correct Answer
C:Managed database backups support restore windows but still require planning and testing. In this case the applicable decision is to use the supported Azure SQL point-in-time restore mechanism and validate recovery.
Incorrect Answers
A:Database auditing provides evidence while database roles govern permissions. That concept explains Azure SQL auditing and least privilege; the situation instead concerns Azure SQL Database backup PITR. Assuming automatic backups undo every external action can hide data gaps.
B:An inner join returns rows with a matching join condition. That concept explains Inner join row matching; the situation instead concerns Azure SQL Database backup PITR. Assuming automatic backups undo every external action can hide data gaps.
D: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 Azure SQL Database backup PITR. Assuming automatic backups undo every external action can hide data gaps.
Question 496
A DBA needs to speed customer ID joins without rewriting every stored row. What is the MOST appropriate next validation or correction?
- Add an index on every column and assume database writes become free.
- Test authentication separately from SELECT/INSERT permissions.
- Compare plans and update costs before and after an index.
- Compare matched and unmatched IDs with a test set.
Explanation
Correct Answer
C:Compare plans and update costs before and after an index. This tests the intended result: execution plans show suitable index use with measured latency improvement.
Incorrect Answers
A:Add an index on every column and assume database writes become free. This unsafe shortcut leaves the B tree index for lookups problem unresolved. Unnecessary indexes can slow frequent writes.
B:Test authentication separately from SELECT/INSERT permissions. It tests Azure SQL authentication and Entra identity rather than the critical B tree index for lookups behavior. Indexes trade extra storage and write overhead for faster supported reads.
D:Compare matched and unmatched IDs with a test set. It tests Inner join row matching rather than the critical B tree index for lookups behavior. Indexes trade extra storage and write overhead for faster supported reads.
Question 497
A vendor assumes Azure patches its stored procedures and application drivers. After selecting the proper Azure SQL managed maintenance responsibility approach, which observation gives the clearest evidence of success?
- The target is selected and known incompatibilities are addressed before cutover.
- View queries return intended permitted columns without creating unmanaged duplicates.
- Database service updates are managed while customer-owned logic is tested.
- Output contains only rows meeting every specified filter condition.
Explanation
Correct Answer
C:Database service updates are managed while customer-owned logic is tested. This is the directly observable result for Azure SQL managed maintenance responsibility; paaS reduces infrastructure upkeep but does not remove all application DBA duties.
Incorrect Answers
A:The target is selected and known incompatibilities are addressed before cutover. This supports Data migration SQL Server assessment, not confirmation of Azure SQL managed maintenance responsibility. The relevant evidence is that database service updates are managed while customer-owned logic is tested.
B:View queries return intended permitted columns without creating unmanaged duplicates. This supports SQL view virtual query object, not confirmation of Azure SQL managed maintenance responsibility. The relevant evidence is that database service updates are managed while customer-owned logic is tested.
D:Output contains only rows meeting every specified filter condition. This supports SQL SELECT filtering WHERE, not confirmation of Azure SQL managed maintenance responsibility. The relevant evidence is that database service updates are managed while customer-owned logic is tested.
Question 498
An audit asks which SQL commands modify stored table data. Which principle BEST explains the correct INSERT UPDATE DELETE DML design decision?
- Foreign keys protect cross-table references to parent keys.
- Data manipulation language changes rows rather than defining the schema.
- PaaS reduces infrastructure upkeep but does not remove all application DBA duties.
- Managed Instance has deployment/networking characteristics that differ from a single SQL Database.
Explanation
Correct Answer
B:Data manipulation language changes rows rather than defining the schema. In this case the applicable decision is to use INSERT UPDATE DELETE for appropriate row mutations with targeted predicates.
Incorrect Answers
A:Foreign keys protect cross-table references to parent keys. That concept explains Foreign key referential integrity; the situation instead concerns INSERT UPDATE DELETE DML. UPDATE without an appropriate WHERE clause can modify every row.
C:PaaS reduces infrastructure upkeep but does not remove all application DBA duties. That concept explains Azure SQL managed maintenance responsibility; the situation instead concerns INSERT UPDATE DELETE DML. UPDATE without an appropriate WHERE clause can modify every row.
D:Managed Instance has deployment/networking characteristics that differ from a single SQL Database. That concept explains SQL Managed Instance virtual network; the situation instead concerns INSERT UPDATE DELETE DML. UPDATE without an appropriate WHERE clause can modify every row.
Question 499
A migrated enterprise database needs private connectivity to on-prem applications. After selecting the proper SQL Managed Instance virtual network approach, which observation gives the clearest evidence of success?
- Updating an order date requires one logical header change.
- Client routes and DNS resolve a reachable MI endpoint under approved rules.
- A planned failover procedure documents data latency and routing behavior.
- Callers execute consistent logic with tested permissions.
Explanation
Correct Answer
B:Client routes and DNS resolve a reachable MI endpoint under approved rules. This is the directly observable result for SQL Managed Instance virtual network; managed Instance has deployment/networking characteristics that differ from a single SQL Database.
Incorrect Answers
A:Updating an order date requires one logical header change. This supports Second normal form partial dependency, not confirmation of SQL Managed Instance virtual network. The relevant evidence is that client routes and DNS resolve a reachable MI endpoint under approved rules.
C:A planned failover procedure documents data latency and routing behavior. This supports Azure SQL active geo-replication tradeoff, not confirmation of SQL Managed Instance virtual network. The relevant evidence is that client routes and DNS resolve a reachable MI endpoint under approved rules.
D:Callers execute consistent logic with tested permissions. This supports Stored procedure reusable server operation, not confirmation of SQL Managed Instance virtual network. The relevant evidence is that client routes and DNS resolve a reachable MI endpoint under approved rules.
Question 500
Security requires encrypted-at-rest storage and authenticated client operations. What is the MOST appropriate next validation or correction?
- Test access-denied behavior separately from storage encryption state.
- Benchmark bursts and steady demand for each candidate option.
- Claim that encrypted storage means all uploaded files are public but safe.
- Validate entities with missing versus null optional properties.
Explanation
Correct Answer
A:Test access-denied behavior separately from storage encryption state. This tests the intended result: stored blobs are encrypted and unauthorized retrieval requests are denied.
Incorrect Answers
B:Benchmark bursts and steady demand for each candidate option. It tests Cosmos DB serverless versus provisioned throughput rather than the critical Storage encryption and access controls behavior. Encryption at rest and access authorization address different risks.
C:Claim that encrypted storage means all uploaded files are public but safe. This unsafe shortcut leaves the Storage encryption and access controls problem unresolved. Encryption alone does not prevent a public anonymous object endpoint.
D:Validate entities with missing versus null optional properties. It tests Table Storage schemaless properties rather than the critical Storage encryption and access controls behavior. Encryption at rest and access authorization address different risks.