DP-300 Monitor, configure, and optimize database resources Practice Test 2 — 15 Questions

Question 1

You need to monitor Azure SQL Database performance over time and receive alerts when CPU usage exceeds 80%. Which Azure service should you use?

Accepted Answer

Azure Monitor Alerts. Azure Monitor Alerts is the correct service because it allows you to create metric-based alert rules that trigger when the CPU percentage of an Azure SQL Database exceeds a defined threshold (e.g., 80%). It continuously monitors performance metrics over time and sends notifications (e.g., email, SMS, or webhook) when the condition is met, fulfilling the requirement for both monitoring and alerting.

Answer

Automatic tuning

Answer

Query Performance Insight

Answer

SQL Assessment

Question 2

You have an Azure SQL Database in the Hyperscale service tier. You need to ensure that read-only workloads are offloaded to a readable secondary. Which configuration should you set?

Accepted Answer

Use ApplicationIntent=ReadOnly in the connection string.. Setting `ApplicationIntent=ReadOnly` in the connection string directs read-only workloads to a readable secondary replica in Azure SQL Database Hyperscale. This offloads read traffic from the primary, improving performance for write-heavy operations. The Hyperscale tier supports this feature without requiring a failover group or explicit read-scale configuration.

Answer

Set ReadOnlyRouting=1 on the database.

Answer

Add the database to a failover group.

Answer

Set ReadScale to 1 on the database.

Question 3

Which THREE metrics should you monitor to detect a memory pressure issue in Azure SQL Database?

Accepted Answer

avg_page_life_expectancy. B (avg_page_life_expectancy) is correct because it measures how long (in seconds) a data page stays in the buffer pool before being evicted. A low value (typically below 300 seconds) indicates that pages are being flushed quickly due to memory pressure, forcing more physical I/O. This is a direct indicator of insufficient memory for the buffer cache.

Answer

avg_io_stall_ms

Answer

log_bytes_used

Question 4

Which TWO configurations can help improve the performance of an Azure SQL Database experiencing high `WRITELOG` waits?

Accepted Answer

Use in-memory OLTP to reduce log writes.. High WRITELOG waits indicate that the transaction log is a bottleneck, often due to excessive log I/O. In-memory OLTP reduces log writes by logging only the delta changes for memory-optimized tables, rather than full row versions, which directly alleviates log pressure. This makes option B correct.

Answer

Enable Transparent Data Encryption (TDE).

Answer

Enable Query Store.

Answer

Increase the frequency of database backups.

Question 5

Which THREE factors should you consider when choosing between vCore and DTU purchase models for Azure SQL Database performance optimization?

Accepted Answer

DTU is simpler for customers who want a bundled metric.. The DTU (Database Transaction Unit) model bundles compute, storage, and I/O into a single, simple metric, making it easier for customers who want a straightforward, pre-configured performance tier without needing to manage individual resources. This contrasts with the vCore model, which requires separate configuration of vCores, memory, and storage, offering more granular control but greater complexity.

Answer

Only vCore supports Azure Hybrid Benefit.

Answer

Only DTU supports elastic pools.

Question 6

You are the database administrator for a large e-commerce company. The production Azure SQL Database (Business Critical, 16 vCores) hosts the order processing system. Recently, users report that order submissions are slow during peak hours. You examine the wait statistics and find that `LCK_M_IX` waits are the top wait type. You also notice that the stored procedure `usp_PlaceOrder` performs an `UPDATE` on the `Orders` table, and there is a high volume of concurrent transactions. The table has a clustered index on `OrderID` and a nonclustered index on `CustomerID`. The procedure uses serializable isolation level. Which action will most effectively reduce the blocking?

Accepted Answer

Change the database to use read committed snapshot isolation (RCSI) and modify the procedure to use read committed.. The primary issue is blocking caused by `LCK_M_IX` waits under the serializable isolation level, which holds range locks and prevents concurrent updates. Changing to read committed snapshot isolation (RCSI) and using read committed eliminates these locks by providing statement-level row versioning, allowing concurrent transactions to read without blocking writers. This directly addresses the high volume of concurrent `UPDATE` operations without requiring schema or hardware changes.

Answer

Increase the vCore count to 24.

Answer

Convert the Orders table to a memory-optimized table.

Answer

Add a nonclustered index on the Status column of the Orders table.

Question 7

You manage an Azure SQL Database (General Purpose, S2) used by a reporting application. The database has a table `FactSales` with 500 million rows. Queries that aggregate sales by date are slow. The execution plan shows a clustered index scan on `FactSales`. The table has a clustered index on `SaleID` and a nonclustered index on `DateKey`. The queries filter by `DateKey` and `ProductKey`. You need to improve query performance without changing the service tier. Which action should you take?

Accepted Answer

Create a covering index on DateKey and ProductKey including the aggregated columns.. The query filters by DateKey and ProductKey and aggregates sales data. A covering index on DateKey and ProductKey that includes the aggregated columns (e.g., SUM(SalesAmount)) allows the query to be satisfied entirely from the index without touching the clustered index, eliminating the costly clustered index scan. This is the most direct and effective way to improve performance without changing the service tier.

Answer

Create a nonclustered index on ProductKey only.

Answer

Partition the table by DateKey.

Answer

Create a clustered columnstore index on the table.

Question 8

You are the database administrator for an Azure SQL Managed Instance hosting a data warehouse workload. You notice that the storage space consumed by the database is significantly larger than expected. The database has multiple large tables with clustered columnstore indexes. You suspect that the columnstore indexes have become fragmented and that deleted rows are consuming space. You need to reclaim storage space with minimal impact on query performance during business hours. What should you do?

Accepted Answer

Perform an ALTER INDEX REORGANIZE with the COMPRESS_ALL_ROW_GROUPS option on the affected columnstore indexes.. REORGANIZE with COMPRESS_ALL_ROW_GROUPS compresses all row groups, including those in the delta store, and removes deleted rows from columnstore indexes. This operation is online and can be performed during business hours with minimal impact on query performance, unlike a rebuild which is offline and resource-intensive. It directly addresses the fragmentation and deleted row space consumption in columnstore indexes.

Answer

Perform an ALTER INDEX REBUILD on the affected columnstore indexes after business hours.

Answer

Perform an ALTER INDEX REORGANIZE on the affected columnstore indexes.

Answer

Rebuild the entire database by creating a new database and copying data.

Question 9

A company has an Azure SQL Database that experiences periodic performance degradation. The database uses the General Purpose service tier. You need to identify the most common performance bottlenecks. You enable the Query Store and collect data for a week. Which Query Store view should you query to find queries that have the highest total resource consumption over time?

Accepted Answer

sys.query_store_query_stats. A is correct because sys.query_store_query_stats aggregates runtime statistics per query across all plans and time intervals, making it the ideal view to identify queries with the highest total resource consumption (e.g., CPU, I/O, duration) over the collected week. Query Store captures historical execution data, and this view provides the cumulative metrics needed to pinpoint the most resource-intensive queries for performance bottleneck analysis.

Answer

sys.query_store_plan

Answer

sys.dm_exec_query_stats

Answer

sys.dm_db_resource_stats

Question 10

You are monitoring an Azure SQL Database using the Automatic Tuning feature. The database has a workload that is read-intensive. You enable the CREATE INDEX and DROP INDEX options. After a week, you observe that the database has created several new indexes automatically. However, you notice that one of the new indexes is causing increased write latency for an application that performs frequent updates. What should you do to resolve the issue without losing the benefits of automatic tuning for other indexes?

Accepted Answer

Manually drop the problematic index using a DROP INDEX command.. Manually dropping the problematic index allows you to resolve the specific performance issue caused by increased write latency while retaining the benefits of automatic tuning for other indexes. The Automatic Tuning feature in Azure SQL Database can create indexes to improve read performance, but these indexes may introduce overhead on write operations. By issuing a DROP INDEX command, you surgically remove only the offending index without disabling the overall tuning mechanism.

Answer

Use the Azure portal to revert all automatic tuning recommendations for the past week.

Answer

Manually create the missing indexes that were dropped by automatic tuning.

Answer

Disable automatic tuning for the entire database.

Question 11

You are responsible for performance tuning of an Azure SQL Database that hosts a customer relationship management (CRM) application. The database has several tables with millions of rows. Users report that a report query that joins four tables is slow. You examine the query execution plan and notice that the database engine is using an Index Spool (Lazy Spool) operator. Which TWO actions should you take to improve query performance? (Choose two.)

Accepted Answer

Create appropriate indexes on the columns used in joins and filters.. An Index Spool (Lazy Spool) operator in an execution plan indicates that the query engine is creating a temporary index on the fly to support join or filter operations, which is a sign of missing or inadequate permanent indexes. Creating appropriate indexes on the columns used in joins and filters (Option C) eliminates the need for the spool, reducing I/O and improving performance. Updating statistics (Option E) ensures the query optimizer has accurate distribution information to generate efficient plans, which can also help avoid spool operations.

Answer

Disable parallelism for the query using the MAXDOP 1 hint.

Answer

Increase the DTU or vCore count of the database.

Answer

Rewrite the query using table hints to force a specific join order.

Question 12

You are the database administrator for an Azure SQL Database used by a financial trading application. The database is in the Business Critical service tier with 16 vCores. The application executes thousands of small, high-frequency transactions per second. Recently, the application's response time has increased, and you observe high PAGELATCH_EX waits in sys.dm_os_waiting_tasks. The database is 500 GB with a single data file (tempdb.mdf) and a single log file (tempdb_log.ldf). TempDB is configured with the default settings. You need to reduce PAGELATCH_EX contention in TempDB. What should you do?

Accepted Answer

Add additional TempDB data files equal to the number of vCores (16).. PAGELATCH_EX contention in TempDB is typically caused by allocation page contention when many concurrent transactions compete for the same system page (e.g., PFS, GAM, SGAM). In Azure SQL Database Business Critical tier, adding multiple TempDB data files equal to the number of vCores (16) reduces contention by distributing allocations across files, each with its own allocation structures. This is a proven best practice for high-concurrency workloads like financial trading applications.

Answer

Move TempDB to Azure Premium Storage for better IO latency.

Answer

Increase the database service tier to 24 vCores.

Answer

Increase the initial size of the TempDB data file to 100 GB.

Question 13

A company runs a critical SQL Server database on Azure Virtual Machines. The database experiences intermittent performance degradation during peak hours. The database administrator notices high I/O latency on the data drive. The current disk configuration uses Standard HDDs. What is the most cost-effective action to reduce I/O latency without changing the virtual machine size?

Accepted Answer

Migrate the data files to Premium SSD managed disks.. Migrating the data files to Premium SSD managed disks is the most cost-effective action to reduce I/O latency without changing the virtual machine size. Premium SSDs provide consistent low-latency performance and higher IOPS/throughput compared to Standard HDDs, directly addressing the high I/O latency during peak hours. This change does not require resizing the VM, keeping compute costs unchanged while improving storage performance.

Answer

Enable instant file initialization in SQL Server.

Answer

Increase the virtual machine size to a series with higher I/O limits.

Answer

Migrate the data files to Standard SSD managed disks.

Question 14

You are monitoring an Azure SQL Database using Query Performance Insight and notice that a specific query has a high average duration and high CPU usage. The query plan shows a clustered index scan on a large table. Which two actions should you take to optimize performance? (Choose two.)

Accepted Answer

Update statistics on the table to ensure the optimizer has current information.. Updating statistics provides the query optimizer with current data distribution information, which can lead to a more efficient query plan, potentially avoiding the clustered index scan. In Azure SQL Database, stale statistics are a common cause of suboptimal plans, and updating them is a low-cost, non-disruptive first step before considering index changes.

Answer

Rebuild the clustered index to reduce fragmentation.

Answer

Force a different query plan using Query Store hints.

Answer

Increase the DTU service tier of the database.

Question 15

Drag and drop the steps to configure an Azure SQL Managed Instance link for disaster recovery in the correct order.

Accepted Answer

Create a secondary managed instance, then create the link, then configure the secondary as readable, then monitor replication, then initiate failover when needed.. The link requires a secondary instance first, then establishing the link, configuring as readable, monitoring, and failing over when needed.

Answer

Create the link, then create a secondary managed instance, then configure as readable, then monitor, then failover.

Answer

Create a secondary managed instance, then create the link, then monitor, then failover, then configure as readable.

Answer

Create a secondary managed instance, then configure as readable, then create the link, then monitor, then failover.