Microsoft DP-300 Administering Azure SQL Solutions Exam Dumps and Practice Test Questions Set 6 Q 76-90

Microsoft DP-300 Administering Azure SQL Solutions Exam Dumps and Practice Test Questions Set 6 Q 76-90

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Question 76: 

You are the database administrator for an Azure SQL Database. Users report that queries are running slower than expected during peak hours. You need to identify queries consuming the most resources. Which Azure portal feature should you use to analyze query performance?

A) Azure Monitor Logs

B) Query Performance Insight

C) Azure Advisor

D) Activity Log

Answer: B

Explanation:

Query performance optimization is a critical responsibility for Azure SQL Database administrators. When users report performance degradation, identifying the root cause requires analyzing which queries consume the most database resources. Azure provides several tools for performance monitoring, but understanding which tool is most appropriate for query-level analysis is essential for efficient troubleshooting and optimization.

Azure SQL Database generates extensive telemetry data about query execution, resource consumption, and performance patterns. This data can be accessed through various Azure services, each designed for different monitoring and analysis purposes. For query-specific performance investigation, administrators need tools that provide query-level metrics including execution time, CPU consumption, logical reads, and execution frequency. These metrics help identify problematic queries that should be optimized through indexing, query rewriting, or parameter tuning.

A) is incorrect because Azure Monitor Logs is a comprehensive logging and monitoring service that collects and analyzes telemetry from various Azure resources. While Azure Monitor Logs can capture database diagnostics and metrics, it requires configuring diagnostic settings, writing KQL queries, and building custom analysis. It’s more suitable for broad infrastructure monitoring, complex analytics, and integration with alerting systems rather than quick query performance identification. For immediate query performance investigation, more specialized tools are more efficient.

B) is correct because Query Performance Insight is specifically designed for identifying and analyzing resource-consuming queries in Azure SQL Database. This built-in feature provides a visual interface showing top queries by CPU consumption, duration, and execution count. Query Performance Insight displays query text, execution statistics, and historical performance trends without requiring additional configuration. Administrators can quickly identify which queries are causing performance issues, view their execution plans, and make informed optimization decisions. This tool is purpose-built for the exact scenario described in the question.

C) is incorrect because Azure Advisor provides best practice recommendations across various Azure services including cost optimization, security, reliability, operational excellence, and performance. While Azure Advisor can suggest performance improvements for Azure SQL Database like index recommendations or service tier adjustments, it doesn’t provide real-time query-level performance analysis. Azure Advisor offers strategic recommendations rather than tactical query performance investigation. It’s valuable for long-term optimization but not for immediate query performance troubleshooting.

D) is incorrect because Activity Log records control plane operations and administrative activities performed on Azure resources, such as creating databases, modifying firewall rules, or changing service tiers. Activity Log doesn’t capture query execution metrics, data plane operations, or performance statistics. It tracks who performed what administrative action and when, which is valuable for auditing and compliance but completely irrelevant for analyzing query performance issues. Activity Log operates at the resource management level, not the query execution level.

After identifying problematic queries using Query Performance Insight, administrators should analyze execution plans, consider adding appropriate indexes, review query logic for optimization opportunities, and potentially implement query hints or rewrite queries for better performance. Additionally, administrators might consider scaling the database service tier if resource constraints are systematic rather than query-specific.

Question 77: 

You manage multiple Azure SQL Databases across different regions. You need to implement a solution that automatically replicates data to a secondary region for disaster recovery with minimal manual intervention. Which Azure SQL Database feature should you implement?

A) Geo-replication

B) Database backup

C) Always On availability groups

D) Log shipping

Answer: A

Explanation:

Disaster recovery planning is essential for maintaining business continuity when primary database regions experience outages due to natural disasters, hardware failures, or other catastrophic events. Azure SQL Database provides several mechanisms for data protection and recovery, but understanding which features provide automatic cross-region replication with minimal administrative overhead is crucial for implementing effective disaster recovery strategies that meet recovery time objectives and recovery point objectives.

High availability and disaster recovery solutions vary in their complexity, automation level, and geographic scope. Some solutions require significant configuration and ongoing management, while others are fully managed by Azure. For cross-region disaster recovery, the solution must replicate data across geographically separated Azure regions to protect against regional failures. The replication should be continuous and automatic to minimize data loss (RPO) and enable quick failover to maintain availability (RTO).

A) is correct because geo-replication (Active geo-replication or Auto-failover groups) provides automatic, continuous asynchronous replication of Azure SQL Database to secondary regions. Active geo-replication allows creating up to four readable secondary databases in the same or different regions. Auto-failover groups build on geo-replication by adding automatic failover capabilities and connection string management. Both features automatically replicate committed transactions to secondary replicas with minimal performance impact on the primary. This fully managed solution requires minimal manual intervention after initial configuration and provides excellent disaster recovery capabilities with low RPO and RTO.

B) is incorrect because database backup, while essential for data protection, doesn’t provide continuous replication to secondary regions or immediate failover capabilities. Azure SQL Database automatically performs full, differential, and transaction log backups, storing them in geo-redundant storage. However, recovery from backups requires manual restoration operations and results in longer recovery times compared to geo-replication. Backups are excellent for point-in-time recovery from data corruption or accidental deletion but aren’t optimal for immediate disaster recovery failover scenarios requiring continuous availability.

C) is incorrect because Always On availability groups are a SQL Server feature for on-premises or Infrastructure as a Service (IaaS) deployments, not applicable to Azure SQL Database as a Platform as a Service (PaaS) offering. Always On availability groups require SQL Server instances running on virtual machines with Windows Server Failover Clustering. Azure SQL Database abstracts infrastructure management and provides different high availability mechanisms. While Always On is powerful for IaaS scenarios, it doesn’t apply to the managed Azure SQL Database service described in the question.

D) is incorrect because log shipping is a legacy SQL Server disaster recovery technique that periodically backs up transaction logs from a primary server, copies them to secondary servers, and restores them. Log shipping involves manual configuration, scheduled jobs, and typically has higher RPO (recovery point objective) due to the periodic nature of log backup and restore operations. It’s not a native Azure SQL Database feature and requires significantly more manual intervention than geo-replication. Modern Azure SQL Database features have superseded log shipping for disaster recovery scenarios.

When implementing geo-replication, administrators should carefully select secondary regions considering geographic distance, compliance requirements, network latency, and cost. Auto-failover groups simplify application connection strings by providing read-write and read-only listener endpoints that automatically redirect to the appropriate replica during failover events.

Question 78: 

You are configuring security for an Azure SQL Database that contains sensitive customer data. You need to ensure that specific columns containing personally identifiable information are automatically encrypted at rest and in transit without requiring application changes. Which Azure SQL Database feature should you implement?

A) Transparent Data Encryption (TDE)

B) Always Encrypted

C) Dynamic Data Masking

D) Row-Level Security

Answer: B

Explanation:

Protecting sensitive data in databases requires implementing appropriate encryption and security controls. Azure SQL Database provides multiple security features addressing different protection requirements. Understanding the distinction between encryption at rest, encryption in transit, column-level encryption, and other security mechanisms is essential for implementing comprehensive data protection that meets compliance requirements like GDPR, HIPAA, or PCI DSS while balancing security with application functionality and performance.

Different security features operate at different layers of the data access path and provide varying levels of protection. Some features protect data while stored on disk, others protect data during transmission, and advanced features maintain encryption even when data is accessed by applications or database administrators. The key challenge is selecting appropriate security controls that provide necessary protection for sensitive data without breaking existing applications or requiring extensive code modifications.

A) is incorrect because Transparent Data Encryption (TDE) encrypts the entire database at rest, protecting against unauthorized access to physical storage media or backups. TDE automatically encrypts data as it’s written to disk and decrypts it when read into memory. However, TDE doesn’t provide column-level encryption, doesn’t maintain encryption when data is accessed by authorized users or applications, and doesn’t specifically target individual columns containing sensitive information. Once data is decrypted and loaded into memory, it’s accessible in plaintext to anyone with appropriate database permissions. TDE is transparent to applications but doesn’t meet the requirement for column-specific encryption.

B) is correct because Always Encrypted provides column-level encryption that maintains data protection even when accessed by database administrators or applications. With Always Encrypted, sensitive columns are encrypted on the client side before being sent to the database, and decryption only occurs on client applications with proper encryption keys. The database server never sees plaintext data, protecting against compromised administrators or infrastructure. Always Encrypted operates transparently to applications using appropriate drivers and connection string settings, requiring minimal application changes. This feature specifically addresses the requirement for column-level encryption of PII without significant application modifications.

C) is incorrect because Dynamic Data Masking obfuscates sensitive data by displaying masked values to unauthorized users but doesn’t actually encrypt the data. Dynamic Data Masking applies masking rules that transform data in query results based on user permissions, showing partial or completely masked values. However, the actual data remains unencrypted in the database, and users with sufficient permissions can still view unmasked data. Dynamic Data Masking provides presentation-layer protection rather than true encryption and doesn’t protect against database administrator access or storage-level attacks.

D) is incorrect because Row-Level Security (RLS) controls which rows users can access based on their identity or role, implementing horizontal data segmentation. RLS uses security predicates to filter rows in query results, ensuring users only see data they’re authorized to access. While valuable for access control in multi-tenant applications or scenarios requiring data isolation, RLS doesn’t encrypt data or protect specific columns. RLS addresses authorization and access control rather than encryption and data protection at the column level.

When implementing Always Encrypted, administrators must carefully manage encryption keys using Azure Key Vault or certificate stores, configure application connection strings with column encryption settings, and ensure client applications have appropriate drivers and permissions to decrypt data. Performance considerations should be evaluated since encrypted columns have limitations on indexing and query operations.

Question 79: 

You need to implement automatic scaling for an Azure SQL Database that experiences unpredictable workload variations throughout the day. The solution should minimize costs during low-usage periods while ensuring adequate performance during peak times. Which compute model should you choose?

A) DTU-based provisioned compute

B) vCore-based provisioned compute

C) Serverless compute

D) Elastic pool with fixed DTUs

Answer: C

Explanation:

Azure SQL Database offers multiple compute models designed for different workload patterns and cost optimization strategies. Understanding the characteristics of each compute model, including scaling behavior, billing mechanisms, and suitability for various workload types, enables administrators to select the most cost-effective option while meeting performance requirements. Workloads with unpredictable or intermittent usage patterns have different optimal configurations compared to steady, predictable workloads.

Compute models in Azure SQL Database differ fundamentally in how they allocate resources and calculate charges. Provisioned compute models allocate dedicated resources continuously regardless of actual usage, providing predictable performance but potentially wasting resources during idle periods. Alternative models can dynamically adjust resources based on actual demand, potentially reducing costs for variable workloads. The key factors in compute model selection include workload predictability, performance requirements, cost sensitivity, and administrative complexity tolerance.

A) is incorrect because DTU-based provisioned compute allocates a fixed bundle of compute, memory, and I/O resources that remain constant regardless of actual workload. DTUs (Database Transaction Units) represent a blended measure of CPU, memory, and I/O. While DTU-based provisioned compute provides predictable performance, it doesn’t automatically scale based on workload variations and bills continuously for the provisioned capacity even during low-usage periods. This model is suitable for predictable workloads with consistent resource requirements but doesn’t minimize costs for unpredictable or intermittent workloads.

B) is incorrect because vCore-based provisioned compute, like DTU-based provisioned compute, allocates specific compute and memory resources continuously. While vCore-based compute provides more granular resource control and is preferred for workloads requiring specific hardware configurations or SQL Server license portability, it still maintains constant resource allocation regardless of actual usage. Although administrators can manually scale vCore databases up or down, this requires intervention and doesn’t provide automatic cost optimization during low-usage periods. Provisioned vCore compute is ideal for predictable, mission-critical workloads requiring guaranteed resources.

C) is correct because serverless compute automatically scales compute resources based on workload demand and pauses the database during inactive periods, charging only for storage during paused time. The serverless model automatically scales between administrator-defined minimum and maximum vCore limits based on actual workload requirements. During periods of inactivity, the database can automatically pause, eliminating compute charges entirely. When activity resumes, the database automatically resumes within seconds. This behavior perfectly addresses unpredictable workload variations, minimizing costs during low-usage periods while ensuring performance during peaks. Serverless is specifically designed for intermittent, unpredictable workloads.

D) is incorrect because elastic pools with fixed DTUs allocate shared resources across multiple databases but still maintain constant provisioned capacity without automatic scaling based on aggregate workload. Elastic pools are cost-effective for managing multiple databases with complementary usage patterns, where some databases are active while others are idle, allowing resource sharing. However, the total pool capacity remains fixed and bills continuously regardless of actual aggregate usage. Elastic pools don’t provide automatic scaling or pausing capabilities for individual databases or the pool itself, making them less optimal for minimizing costs during extended low-usage periods.

When implementing serverless compute, administrators should configure appropriate minimum and maximum vCore values, define auto-pause delay settings based on application tolerance for resume latency, and monitor actual usage patterns to validate cost savings. Serverless is particularly effective for development/test databases, small applications with intermittent usage, and new applications with uncertain workload patterns.

Question 80: 

You are implementing Azure SQL Database auditing to track database events for compliance purposes. You need to send audit logs to a centralized workspace where they can be analyzed alongside logs from other Azure resources. Where should you configure the audit logs to be stored?

A) Azure Storage account only

B) Event Hub only

C) Log Analytics workspace

D) Azure Blob storage with public access

Answer: C

Explanation:

Auditing and compliance monitoring are critical components of database security and regulatory compliance. Azure SQL Database auditing tracks database events and writes them to designated storage destinations. Understanding different audit log destinations and their capabilities for log analysis, retention, integration with security tools, and correlation with other resource logs is essential for implementing comprehensive security monitoring and compliance reporting solutions that meet organizational and regulatory requirements.

Audit logs can be routed to different destinations serving different purposes. Some destinations provide long-term archival storage, others enable real-time streaming to event processing systems, and still others provide powerful query and analysis capabilities. The optimal destination depends on how the audit data will be used, whether it needs to be correlated with other logs, retention requirements, and what analysis and alerting capabilities are needed. Centralized log management enables security operations teams to detect threats spanning multiple resources and services.

A) is incorrect because while Azure Storage accounts provide cost-effective long-term retention of audit logs, they don’t offer built-in log analysis, querying, or correlation capabilities with other Azure resource logs. Storage accounts are excellent for compliance retention and archival purposes, but accessing and analyzing audit data requires downloading and processing logs separately. Storage accounts don’t provide the centralized analysis workspace described in the question where logs from multiple resources can be queried together. For pure archival, storage accounts are appropriate, but they lack integrated analysis capabilities.

B) is incorrect because Event Hub provides real-time event streaming capabilities for ingesting audit logs into external systems or custom applications but doesn’t itself provide log storage, analysis, or querying capabilities. Event Hub is a data streaming platform that acts as an intermediary, forwarding audit logs to downstream consumers like SIEM (Security Information and Event Management) systems, custom analytics applications, or third-party monitoring tools. While valuable for integration scenarios, Event Hub alone doesn’t meet the requirement for a centralized workspace for log analysis.

C) is correct because Log Analytics workspace provides centralized log storage, powerful querying capabilities using Kusto Query Language (KQL), visualization, alerting, and integration with Azure Monitor and Azure Sentinel. Log Analytics workspaces can ingest logs from numerous Azure resources including Azure SQL Database, virtual machines, Azure Active Directory, and other services, enabling correlated analysis across the entire environment. Security analysts can create queries that span multiple log sources, build dashboards, configure alerts for suspicious activities, and integrate with Azure Sentinel for advanced threat detection. This fully addresses the requirement for centralized analysis alongside other resource logs.

D) is incorrect because Azure Blob storage with public access would be a severe security misconfiguration that exposes sensitive audit logs to the internet. Audit logs contain sensitive information about database access patterns, queries, and security events that should never be publicly accessible. This option represents a security violation rather than a proper configuration. Even private Azure Blob storage (essentially Azure Storage account) lacks the integrated analysis capabilities provided by Log Analytics workspace, making it unsuitable even if properly secured.

When configuring auditing to Log Analytics workspace, administrators should define appropriate retention policies, create custom KQL queries for common analysis scenarios, establish alerting rules for suspicious activities, and consider integrating with Azure Sentinel for advanced security analytics and automated response capabilities. Audit policies should capture relevant events without excessive verbosity that increases storage costs.

Question 81: 

You manage an Azure SQL Database that supports a critical business application. The business requires the ability to restore the database to any point in time within the last 35 days. Which backup configuration should you implement?

A) Configure geo-redundant backup storage with default retention

B) Configure long-term retention policy with 5 weeks of retention

C) Modify the point-in-time restore retention period to 35 days

D) Implement manual daily backups for 35 days

Answer: C

Explanation:

Backup and restore capabilities are fundamental to database administration and disaster recovery planning. Azure SQL Database automatically performs backups using a combination of full, differential, and transaction log backups to enable point-in-time restore (PITR) capabilities. Understanding how backup retention works, the difference between short-term retention for operational recovery and long-term retention for compliance, and how to configure these settings appropriately ensures that databases can be recovered from accidental data corruption, deletion, or application errors while meeting business requirements.

Azure SQL Database’s backup system operates automatically without administrator intervention, but retention policies can be configured to meet specific business requirements. The default short-term retention period varies by service tier but typically provides 7 days of point-in-time restore capability. For scenarios requiring longer operational recovery windows, administrators can extend this retention period. Long-term retention serves a different purpose, providing weekly, monthly, or yearly backups for compliance and archival rather than operational recovery.

A) is incorrect because while geo-redundant backup storage provides geographic redundancy for backup files, protecting against regional disasters, it doesn’t change the retention period for point-in-time restore. Geo-redundant storage replicates backups to a paired Azure region, enabling geo-restore capabilities if the primary region becomes unavailable. However, the default retention period (typically 7 days) remains unchanged. Geo-redundant storage addresses geographic redundancy, not retention duration. The backup storage redundancy option and retention period are independent configuration settings.

B) is incorrect because long-term retention (LTR) policies are designed for compliance and archival purposes, storing weekly, monthly, or yearly full database backups for extended periods up to 10 years. However, LTR backups don’t provide point-in-time restore capabilities—they only allow restoration to the specific moment when each LTR backup was created. For point-in-time restore within the last 35 days, requiring restoration to any arbitrary moment including seconds before data corruption, short-term retention (PITR) is necessary. LTR serves a different purpose and doesn’t meet the point-in-time requirement.

C) is correct because modifying the point-in-time restore retention period to 35 days directly addresses the requirement. Azure SQL Database allows configuring PITR retention from 1 to 35 days (7 to 35 days for most service tiers). By setting the retention period to 35 days, the database maintains continuous backup coverage enabling restoration to any point in time within that window. This configuration ensures that transaction log backups are retained sufficiently to support PITR operations for the entire 35-day period. This setting precisely meets the business requirement for point-in-time recovery capability.

D) is incorrect because Azure SQL Database automatically performs backups without requiring manual intervention. Implementing manual daily backups would be redundant, administratively burdensome, and wouldn’t provide true point-in-time restore capabilities. Manual backups would only enable restoration to the specific times when backups were taken, not to arbitrary points in time. Additionally, manual backups would consume extra storage and require maintenance scripts. Azure’s automated backup system with configured retention is superior to manual backup approaches for operational recovery scenarios.

Extending PITR retention beyond 7 days incurs additional storage costs proportional to the retention period and database size. Administrators should balance business recovery requirements with cost considerations, implementing appropriate retention policies that satisfy operational needs without excessive expense. For databases requiring both operational recovery and long-term compliance retention, configuring both PITR retention and LTR policies provides comprehensive backup coverage.

Question 82: 

You are monitoring the performance of an Azure SQL Database and notice that query performance has degraded. You discover that the database has run out of tempdb space. Which of the following actions will MOST effectively resolve this issue in Azure SQL Database?

A) Manually expand tempdb file size

B) Scale up the database service tier

C) Clear tempdb by restarting the database

D) Add additional tempdb data files

Answer: B

Explanation:

Understanding tempdb behavior and resource allocation in Azure SQL Database differs significantly from traditional SQL Server administration. In on-premises SQL Server, administrators have direct control over tempdb configuration including file sizes, number of files, and growth settings. However, Azure SQL Database as a managed PaaS offering abstracts infrastructure management, automatically configuring and managing tempdb based on the database service tier. Understanding this fundamental difference is crucial for troubleshooting performance issues related to temporary storage.

Tempdb is a system database used for temporary objects, internal sorting operations, version stores for row versioning, and other transient workload needs. When queries require extensive sorting, use table variables, create temporary tables, or perform operations that exceed available memory, tempdb space is consumed. In Azure SQL Database, tempdb size and configuration are determined by the service tier rather than administrator configuration. Each service tier allocates specific amounts of tempdb space proportional to the compute resources.

A) is incorrect because Azure SQL Database doesn’t provide direct access to modify tempdb file sizes or configuration. Unlike SQL Server on virtual machines where administrators have full control over system database configuration, Azure SQL Database manages tempdb automatically as part of the managed service. Administrators cannot manually expand tempdb, add files, or modify tempdb settings. The platform automatically configures tempdb based on the service tier. This administrative limitation is a trade-off for the benefits of managed service operations.

B) is correct because scaling up the database service tier increases all allocated resources including compute, memory, storage, and critically, tempdb space. When tempdb space is exhausted, it indicates that the current service tier’s resources are insufficient for the workload. Moving to a higher service tier (for example, from S3 to S6 in the Standard tier, or from GP_Gen5_2 to GP_Gen5_4 in the vCore model) allocates more tempdb space automatically. This is the appropriate and only direct method for increasing tempdb capacity in Azure SQL Database. Service tier scaling can be performed through Azure Portal, PowerShell, Azure CLI, or T-SQL.

C) is incorrect because while clearing tempdb by restarting might temporarily resolve the immediate space issue, it doesn’t address the root cause that the workload requires more tempdb space than currently available. Restarting the database clears tempdb contents but also causes application downtime and only provides temporary relief. If the workload continues generating the same tempdb demands, space will be exhausted again. Database restart is disruptive and doesn’t provide a sustainable solution. Additionally, excessive database restarts impact availability and user experience.

D) is incorrect because, similar to option A, administrators cannot manually add tempdb data files in Azure SQL Database. The number of tempdb files, their sizes, and configuration are managed automatically by Azure based on the service tier. In traditional SQL Server, adding multiple tempdb data files improves concurrency by reducing allocation contention, but this configuration is handled automatically in Azure SQL Database. Administrators lack the permissions and access to modify system database configurations in the managed PaaS offering.

Before scaling up, administrators should investigate which queries or operations are consuming excessive tempdb space using Query Store, sys.dm_db_task_space_usage, or sys.dm_db_session_space_usage DMVs. Query optimization, adding appropriate indexes, or restructuring queries to reduce temporary object creation might reduce tempdb requirements, potentially avoiding the need for scaling or allowing scaling to a less expensive tier while still meeting performance requirements.

Question 83: 

You need to implement a solution that allows developers to query an Azure SQL Database without granting them direct access to production data. The solution should automatically mask sensitive data based on user permissions. Which feature should you configure?

A) Always Encrypted

B) Transparent Data Encryption

C) Dynamic Data Masking

D) Row-Level Security

Answer: C

Explanation:

Balancing security requirements with operational needs is a common challenge in database administration. Development teams often need access to production databases for troubleshooting, performance analysis, or understanding data patterns, but exposing sensitive production data creates security and compliance risks. Azure SQL Database provides several features for protecting sensitive data, but understanding which feature addresses specific scenarios—hiding data from unauthorized users without restricting database access entirely—is essential for implementing appropriate security controls.

Different security features operate at different layers and provide different types of protection. Some features encrypt data so it’s completely inaccessible without decryption keys, while others filter which records users can see, and still others obfuscate sensitive values while maintaining data structure and relationships. The appropriate feature depends on whether the goal is preventing data access entirely, limiting access to specific records, or allowing access to data structure and patterns while hiding sensitive values.

A) is incorrect because Always Encrypted provides column-level encryption that maintains data encryption even when accessed by database administrators. With Always Encrypted, sensitive columns are encrypted client-side and remain encrypted in the database, with decryption occurring only on authorized client applications with proper encryption keys. This feature is designed for maximum data protection where even database administrators shouldn’t see plaintext values. However, Always Encrypted doesn’t allow querying or viewing masked versions of data—users either have decryption keys and see plaintext or don’t have keys and cannot query encrypted columns effectively.

B) is incorrect because Transparent Data Encryption (TDE) encrypts the entire database at rest, protecting physical storage media and backups from unauthorized access. TDE automatically encrypts data as it’s written to disk and decrypts it when loaded into memory. However, TDE operates transparently to all authorized users—once authenticated to the database, users see unencrypted data regardless of permissions. TDE provides no mechanism for masking sensitive data based on user identity or permissions. It protects data at rest but not data in use.

C) is correct because Dynamic Data Masking (DDM) automatically obfuscates sensitive data in query results based on user permissions without modifying the actual stored data. Administrators define masking rules on specific columns specifying how data should be masked (full masking, partial masking, random masking, or custom). When users without unmasking privileges query masked columns, they receive masked values (for example, «XXXX» for full masking, «XXX-XX-1234» for partial masking of SSN). Privileged users granted unmask permission see actual data. This allows developers to query production databases for analysis while protecting sensitive information, perfectly addressing the scenario.

D) is incorrect because Row-Level Security (RLS) controls which rows users can access based on their identity, implementing horizontal data segmentation. RLS uses security predicates that filter rows in query results, ensuring users only see records they’re authorized to access (for example, salespeople only seeing their own customers, or users only seeing data for their tenant in multi-tenant applications). While valuable for access control, RLS doesn’t mask values within visible rows—it controls row visibility entirely. RLS addresses «who can see which records» rather than «how sensitive values appear.»

When implementing Dynamic Data Masking, administrators should identify columns containing sensitive data (PII, financial information, healthcare data), define appropriate masking functions for each column type, grant unmask permissions to users requiring access to actual values, and document masked columns. DDM is not a security feature preventing determined attackers from inferring data through repeated queries, but rather a convenience feature for everyday data protection in non-hostile scenarios.

Question 84: 

You are planning a migration of an on-premises SQL Server database to Azure SQL Database. The database uses SQL Server Agent jobs for routine maintenance and data processing tasks. Which Azure service should you use to replicate this functionality?

A) Azure Automation

B) Azure Logic Apps

C) Azure Functions

D) Elastic jobs

Answer: D

Explanation:

Migrating from SQL Server to Azure SQL Database requires understanding the architectural differences between on-premises SQL Server and Azure SQL Database as a managed PaaS offering. SQL Server Agent is a scheduling service built into SQL Server that executes scheduled jobs including T-SQL scripts, SSIS packages, PowerShell scripts, and other maintenance tasks. However, Azure SQL Database doesn’t include SQL Server Agent because it’s a managed service where Microsoft handles platform-level maintenance. Understanding alternative scheduling mechanisms in Azure is essential for successful database migrations.

Different Azure services provide job scheduling and automation capabilities suited for different scenarios. Some services are general-purpose automation platforms, others are designed for workflow orchestration, and specific services target database-related scheduling. The optimal choice depends on the nature of tasks being scheduled, whether they require T-SQL execution against databases, how many databases need scheduling, and integration requirements with other systems. For database-specific scheduling requirements, specialized database job services provide the most appropriate functionality.

A) is incorrect because while Azure Automation provides powerful automation capabilities including runbook execution, scheduling, and integration with various Azure services, it’s a general-purpose automation platform not specifically designed for database job scheduling. Azure Automation runbooks can execute T-SQL through PowerShell or Python scripts, but this requires additional coding and doesn’t provide native database job management features like job history tracking, retry logic, or target group management for multiple databases. Azure Automation is better suited for infrastructure automation and management tasks rather than database-specific job scheduling.

B) is incorrect because Azure Logic Apps is a workflow orchestration service designed for integrating applications, data, and services across cloud and on-premises environments. Logic Apps provides visual workflow design, numerous connectors, and event-driven execution. While Logic Apps can interact with databases and execute scheduled workflows, it’s designed for business process automation and integration scenarios rather than traditional database maintenance jobs. Logic Apps would be excessive and inappropriate for typical SQL Agent job migrations like index maintenance, statistics updates, or data archival tasks.

C) is incorrect because Azure Functions is a serverless compute service for running event-driven code without managing infrastructure. Functions can execute on schedules using timer triggers and can interact with databases, making them technically capable of replacing some SQL Agent jobs. However, Functions require code development, lack native database job management features, and aren’t specifically designed for database maintenance workflows. While Functions are excellent for event-driven application logic and lightweight scheduled tasks, they’re not the purpose-built solution for migrating SQL Server Agent jobs.

D) is correct because Elastic jobs (Azure SQL Database elastic jobs) is specifically designed to replace SQL Server Agent functionality in Azure SQL Database environments. Elastic jobs enables scheduling and executing T-SQL scripts across single databases, multiple databases, or all databases in elastic pools. It provides job definitions, schedules, execution history, retry policies, and parallel execution across multiple targets. Elastic jobs is the native Azure solution for database job scheduling, making it the most appropriate choice for migrating SQL Server Agent jobs to Azure SQL Database. It provides familiar functionality in a managed service context.

When implementing elastic jobs, administrators create a job agent (which uses its own Azure SQL Database for job metadata), define job credentials for target databases, create target groups specifying which databases jobs should execute against, define job steps containing T-SQL scripts, and configure schedules. Understanding elastic jobs’ capabilities and limitations compared to SQL Server Agent helps in planning appropriate migrations and potentially refactoring job logic where necessary.

Question 85: 

You need to configure an Azure SQL Database to allow connections only from specific Azure Virtual Networks while blocking all public internet access. Which security feature should you implement?

A) Server-level firewall rules

B) Database-level firewall rules

C) Virtual Network service endpoints

D) Azure Private Link

Answer: D

Explanation:

Network security for Azure SQL Database requires understanding multiple networking features that control connectivity from different sources. Azure SQL Database, being a PaaS offering, is accessible via public endpoints by default, necessitating additional configuration to restrict access to trusted networks. Different networking features provide varying levels of network isolation, from simple IP-based filtering to complete private network integration. Selecting the appropriate feature depends on security requirements, whether public internet access should be allowed at all, and integration needs with Azure Virtual Networks.

Network security operates through multiple layers. Firewall rules provide IP-based filtering, determining which source IP addresses can attempt connections. Virtual Network integration features control whether databases can be accessed through private Azure networking rather than public internet. The distinction between allowing specific networks to access public endpoints versus completely eliminating public endpoints is crucial for meeting stringent security and compliance requirements that prohibit any public internet exposure.

A) is incorrect because server-level firewall rules filter connections based on source IP addresses but don’t eliminate public internet access or restrict connectivity specifically to Azure Virtual Networks. Firewall rules allow specifying IP ranges that can connect, but the database remains accessible via its public endpoint. Any source with an allowed IP address can connect from anywhere on the internet. Firewall rules don’t provide Virtual Network-specific access control or eliminate the public attack surface. They’re appropriate for basic IP filtering but don’t meet the requirement to allow only VNet connections while blocking all public access.

B) is incorrect because database-level firewall rules, like server-level firewall rules, filter based on source IP addresses and don’t provide Virtual Network-specific access control. Database-level rules apply to individual databases rather than all databases on a server, offering more granular control, but still operate through IP filtering on the public endpoint. Database-level firewall rules don’t eliminate public internet access or restrict connectivity to Azure Virtual Networks. They provide per-database IP filtering but don’t address the fundamental requirement for VNet-only access.

C) is incorrect because while Virtual Network service endpoints enable Azure services including Azure SQL Database to be accessed through VNet private IP addresses, they don’t completely eliminate public endpoint access. Service endpoints optimize routing by keeping traffic on the Azure backbone network and provide VNet-based access control through server firewall rules. However, the database public endpoint remains active, and with appropriate firewall rules, could still be accessed from the internet. Service endpoints improve security and performance but don’t fully satisfy the requirement to block all public internet access.

D) is correct because Azure Private Link (Private Endpoint) creates a private network interface in your Virtual Network with a private IP address, completely eliminating public internet access to the database. With Private Link, the database is accessed exclusively through the private endpoint within your VNet, and the public endpoint can be completely disabled. Traffic never leaves the Azure network, providing the highest level of network isolation. Private Link fully addresses the requirement to allow connections only from specific Virtual Networks while blocking all public internet access. This provides the strongest network security posture for Azure SQL Database.

Implementing Private Link requires creating a private endpoint resource in the target VNet, configuring DNS to resolve the database FQDN to the private endpoint IP address (using Azure Private DNS zones is recommended), and optionally disabling public network access on the SQL server. Private Link incurs additional costs compared to service endpoints but provides superior security through complete network isolation, making it appropriate for highly sensitive workloads with strict security requirements.

Question 86: 

You manage an Azure SQL Database that experiences periodic performance issues. You need to automatically detect and resolve common performance problems without manual intervention. Which Azure SQL Database feature should you enable?

A) Query Performance Insight

B) Automatic tuning

C) Azure Advisor

D) Performance recommendations

Answer: B

Explanation:

Database performance optimization traditionally requires continuous monitoring, expert analysis, and manual implementation of improvements like creating indexes or forcing query plans. Azure SQL Database includes intelligent features that leverage machine learning and telemetry from millions of databases to automatically identify and implement performance improvements. Understanding the distinction between features that provide recommendations requiring manual implementation versus features that automatically implement improvements is essential for minimizing administrative overhead while maintaining optimal performance.

Performance management features vary in their level of automation. Some features identify performance issues and recommend solutions but require administrator approval and implementation. Others automatically implement proven optimizations without human intervention, continuously adapting to workload changes. The appropriate feature depends on organizational preferences for automation versus manual control, risk tolerance for automatic changes, and administrative resources available for performance management. Highly automated features reduce operational burden but require trust in the underlying intelligence.

A) is incorrect because Query Performance Insight is a monitoring and analysis tool that identifies resource-consuming queries and provides performance statistics, but it doesn’t automatically resolve performance issues. Query Performance Insight visualizes top queries by CPU, duration, or execution count, displays query text and execution plans, and tracks performance trends over time. While valuable for diagnosing performance problems, Query Performance Insight requires administrators to analyze findings and manually implement optimizations. It’s a diagnostic tool rather than an automated resolution mechanism, helpful for understanding problems but not for automatic remediation.

B) is correct because Automatic tuning uses artificial intelligence to continuously monitor database performance, detect issues, and automatically implement proven optimizations including creating and dropping indexes and forcing query plans. When automatic tuning identifies a beneficial index based on workload patterns, it creates the index, monitors performance impact, and automatically reverts the change if performance degrades. Similarly, it can force query plans for queries experiencing plan regression. Automatic tuning operates continuously without administrator intervention, making it the only feature that both detects and automatically resolves performance problems as specified in the question.

C) is incorrect because Azure Advisor provides best practice recommendations across various Azure services including cost optimization, security, reliability, and performance, but recommendations require manual review and implementation. For Azure SQL Database, Advisor might suggest creating specific indexes, adjusting service tiers, or implementing other optimizations. However, administrators must evaluate these recommendations and manually implement them through Azure Portal, T-SQL, or scripts. Azure Advisor is a recommendation engine rather than an automation engine, providing guidance but not automatic resolution of issues.

D) is incorrect because performance recommendations (available through Azure Portal, sys.dm_db_tuning_recommendations DMV, or REST API) identify potential performance improvements like index creation or plan forcing but don’t automatically implement changes. Performance recommendations are generated by the same intelligence that powers automatic tuning, but when automatic tuning is disabled, recommendations require manual review and implementation. Recommendations provide visibility into potential optimizations but don’t meet the requirement for automatic resolution without manual intervention. They’re the manual alternative to automatic tuning.

When enabling automatic tuning, administrators can configure which automatic tuning options to enable: Create Index (automatically creates beneficial indexes), Drop Index (removes unused indexes), and Force Last Good Plan (forces stable query plans for queries experiencing plan regression). Organizations can enable all options for maximum automation or selectively enable specific options based on their comfort level with automatic changes. Automatic tuning actions are logged and can be monitored through DMVs and Azure Portal.

Question 87: 

You are configuring monitoring for an Azure SQL Database to receive immediate notifications when database CPU utilization exceeds 80% for more than 5 minutes. Which Azure service should you use to create this alert?

A) Azure Service Health

B) Azure Monitor

C) Azure Security Center

D) Azure Log Analytics

Answer: B

Explanation:

Proactive monitoring and alerting are essential for maintaining database availability and performance. While monitoring tools provide visibility into system health and performance metrics, alert rules enable automated notifications when predefined conditions are met, allowing administrators to respond quickly to issues before they impact users. Azure provides several monitoring and alerting services, but understanding which service handles metric-based alerts for Azure resources is crucial for implementing effective operational monitoring.

Different Azure services serve different monitoring purposes. Some services focus on platform health and service incidents, others on security posture and threat detection, and still others on log aggregation and analysis. For metric-based alerting on resource performance like CPU utilization, memory usage, or storage consumption, the appropriate service must collect these metrics continuously and evaluate alert conditions in near real-time. Understanding the distinct capabilities of each monitoring service ensures administrators configure alerts through the correct mechanism.

A) is incorrect because Azure Service Health provides information about Azure platform service incidents, planned maintenance, and health advisories affecting your Azure resources, but doesn’t monitor or alert on resource-specific performance metrics like database CPU utilization. Service Health notifies you when Azure services experience outages, when maintenance is planned for your subscriptions, or when deprecated features affect your resources. While valuable for understanding platform-level issues, Service Health doesn’t provide the granular per-resource metric monitoring and alerting capabilities needed for database performance alerts.

B) is correct because Azure Monitor is the comprehensive monitoring platform for Azure resources that collects metrics and logs, enables visualization through dashboards, and provides alerting capabilities based on metric thresholds, log queries, or activity log events. Azure Monitor automatically collects platform metrics from Azure SQL Database including CPU percentage, and allows creating metric alert rules with specified conditions like «CPU percentage greater than 80% for more than 5 minutes.» When conditions are met, Azure Monitor triggers configured action groups that can send email, SMS, push notifications, trigger webhooks, or execute automation runbooks. This fully addresses the requirement for CPU utilization alerts.

C) is incorrect because Azure Security Center (now part of Microsoft Defender for Cloud) focuses on security posture management, threat detection, and security recommendations rather than performance metric monitoring. Security Center identifies security vulnerabilities, compliance issues, and suspicious activities across Azure resources. While Security Center can alert on security-related events like unusual database access patterns or potential SQL injection attempts, it doesn’t provide performance metric monitoring or alerting for operational metrics like CPU utilization. Security Center addresses security rather than performance monitoring.

D) is incorrect because while Azure Log Analytics is a component of Azure Monitor that collects and analyzes log data, enabling complex queries and log-based alerts, the scenario describes a metric-based alert on CPU utilization. Azure SQL Database emits CPU percentage as a platform metric rather than a log entry. While metric data can be sent to Log Analytics for analysis and log-based alerts could technically be created, this approach is unnecessarily complex compared to using Azure Monitor’s native metric alert capabilities. Log Analytics is appropriate for log-based alerts but not the primary mechanism for simple metric threshold alerts.

To implement this alert, administrators would navigate to the Azure SQL Database in Azure Portal, select Alerts, create a new alert rule, define the condition (CPU percentage greater than 80% for 5 minutes), configure an action group specifying notification recipients and methods, and provide alert details. Alert rules can be created through Azure Portal, PowerShell, Azure CLI, or ARM templates for automated deployment across multiple databases.

Question 88: 

You need to migrate an existing on-premises SQL Server database to Azure SQL Database with minimal downtime. The database is actively used by applications during business hours. Which migration method should you use?

A) Export/Import using BACPAC files

B) Azure Database Migration Service online migration

C) Backup and restore to Azure SQL Database

D) Manual T-SQL script generation and execution

Answer: B

Explanation:

Database migration represents a critical project phase where minimizing downtime and ensuring data consistency are paramount concerns. Different migration methods provide varying levels of downtime, complexity, and risk. Understanding the characteristics of each migration approach, including whether they support online migration with continuous data synchronization versus offline migration requiring extended downtime, is essential for selecting the appropriate method based on business requirements, application tolerance for downtime, and database size.

Migration methods fundamentally differ in how they handle data transfer and cutover. Offline migrations require taking the source database offline or read-only, exporting data, transferring it to Azure, and importing it before applications can reconnect to the new Azure SQL Database. Online migrations establish continuous data synchronization between source and target databases, allowing the source to remain active while data is initially replicated, then keeping the target synchronized until the cutover moment when applications are redirected to Azure with minimal downtime.

A) is incorrect because Export/Import using BACPAC files is an offline migration method requiring significant downtime proportional to database size. The process involves exporting the source database to a BACPAC file (a compressed file containing schema and data), transferring the file to Azure, and importing it into a new Azure SQL Database. During export, the source database should be quiesced to ensure transactional consistency, and the database remains unavailable while export, transfer, and import operations complete. For large databases or scenarios requiring minimal downtime, BACPAC export/import is inappropriate. It’s suitable for small databases or migration scenarios where extended downtime is acceptable.

B) is correct because Azure Database Migration Service (DMS) online migration mode supports minimal-downtime migrations by establishing continuous data synchronization between the on-premises source and Azure SQL Database target. DMS performs an initial full migration, then continuously replicates changes from the source to the target using transaction log reading or change data capture. The source database remains fully operational during migration. When ready, administrators perform cutover by stopping applications, allowing final changes to synchronize, then redirecting applications to Azure—typically requiring only minutes of downtime regardless of database size. This directly addresses the minimal downtime requirement for actively used databases.

C) is incorrect because Azure SQL Database doesn’t support native restore of SQL Server .bak backup files. The restore functionality in Azure SQL Database differs from SQL Server—only BACPAC imports and long-term retention backup restores within Azure SQL Database are supported. SQL Server .bak files cannot be directly restored to Azure SQL Database. This limitation means traditional backup/restore workflows used for migrations between SQL Server instances don’t apply to Azure SQL Database migrations. For SQL Server backup restore capability, Azure SQL Managed Instance would be required instead of Azure SQL Database.

D) is incorrect because manually generating and executing T-SQL scripts for schema and data is error-prone, time-consuming, and represents an offline migration method with potentially extensive downtime. This approach involves scripting out database schema (tables, views, procedures, etc.), transferring scripts to Azure, executing them to create objects, then using bulk copy or INSERT statements to transfer data. The source database must be quiesced to ensure data consistency, and downtime extends throughout the manual process. This method lacks automation, error handling, and synchronization capabilities, making it inappropriate for production migrations requiring minimal downtime.

Azure Database Migration Service online migration provides the most robust minimal-downtime migration path. Prerequisites include installing DMS, configuring network connectivity between on-premises and Azure, ensuring source database has appropriate transaction log configuration, creating the target Azure SQL Database, and planning the cutover window. Post-migration validation should confirm data integrity, application functionality, and performance before decommissioning the source database.

Question 89: 

You manage an Azure SQL Database configured with zone-redundant deployment. Which of the following high availability benefits does this configuration provide?

A) Protection against datacenter-level failures within a region

B) Protection against region-wide outages

C) Automatic failover to a paired region

D) Point-in-time restore capability

Answer: A

Explanation:

Understanding different levels of availability and disaster recovery protection in Azure SQL Database is crucial for designing solutions that meet business continuity requirements. Azure SQL Database provides multiple features addressing different failure scenarios, from hardware failures to datacenter outages to region-wide disasters. Zone redundancy and geo-replication serve different purposes, protect against different failure types, and have different cost and performance characteristics. Correctly selecting and combining these features ensures appropriate protection for each workload’s availability requirements.

Azure regions with availability zone support are divided into multiple physically separate locations called zones, each with independent power, cooling, and networking. Zone-redundant deployments distribute database replicas across multiple zones within a region, protecting against zone-level failures without manual intervention. This differs from geo-replication, which distributes replicas across different Azure regions for disaster recovery. Understanding the geographic scope and failure types addressed by each feature prevents confusion and ensures appropriate architecture decisions.

A) is correct because zone-redundant deployment distributes database replicas across multiple availability zones within a single Azure region, providing automatic failover capability if an entire datacenter (availability zone) fails. Azure manages replica synchronization and failover automatically without data loss or required administrator intervention. If a zone experiences failure due to power outage, cooling failure, network issues, or other zone-level problems, the database automatically fails over to a healthy zone within seconds. This provides high availability within a region protecting against datacenter-level failures while maintaining single-region deployment. Zone redundancy is available for Premium, Business Critical, and Hyperscale service tiers.

B) is incorrect because zone-redundant deployment operates within a single Azure region and doesn’t protect against region-wide outages affecting all availability zones. If an entire region becomes unavailable due to natural disaster, widespread infrastructure failure, or other regional issues, a zone-redundant database within that region would be unavailable. Protection against region-wide outages requires geo-replication or auto-failover groups that distribute replicas across multiple Azure regions. Zone redundancy and geo-replication address different failure scenarios—zone redundancy for datacenter failures, geo-replication for regional failures.

C) is incorrect because zone-redundant deployment doesn’t provide automatic failover to a paired region. Zone redundancy operates within a single region, automatically failing over between zones but not between regions. Automatic failover to another region requires configuring auto-failover groups, which establish geo-replicated secondary databases and manage failover across regions. Paired regions are Azure’s concept of geographically separated region pairs for disaster recovery, but utilizing paired regions requires explicitly configuring geo-replication. Zone redundancy and geo-replication can be combined but are separate features.

D) is incorrect because point-in-time restore capability is provided by Azure SQL Database’s automated backup system and is independent of zone redundancy configuration. All Azure SQL Databases automatically receive full, differential, and transaction log backups enabling point-in-time restore within the retention period, regardless of whether zone redundancy is enabled. Point-in-time restore protects against data corruption or accidental deletion rather than infrastructure failures. Zone redundancy addresses high availability for infrastructure failures, while point-in-time restore addresses operational recovery from data-level issues. These are complementary but separate capabilities.

Zone-redundant deployment provides enhanced availability within a region but doesn’t replace the need for geo-replication in disaster recovery scenarios. Organizations should implement both zone redundancy for high availability and geo-replication for disaster recovery when business requirements demand protection against both datacenter-level and region-level failures. Zone redundancy incurs higher costs compared to non-zone-redundant deployments due to additional replica infrastructure across zones.

Question 90: 

You are optimizing query performance for an Azure SQL Database. Analysis shows that a frequently executed query performs poorly due to an implicit data type conversion. Which of the following actions would MOST effectively resolve this performance issue?

A) Increase the database service tier

B) Modify the query to use explicit data type matching

C) Enable automatic tuning

D) Create a covering index on all columns

Answer: B

Explanation:

Query performance optimization requires understanding how query execution works and identifying root causes of performance problems. Implicit data type conversions occur when SQL Server must convert data from one type to another because the query compares or combines columns of different data types. These conversions can prevent index usage, cause expensive table scans, and generate CPU overhead. Effective performance tuning identifies such issues and implements targeted solutions rather than applying generic approaches like hardware scaling that address symptoms rather than root causes.

SQL Server’s query optimizer generates execution plans based on query structure, available indexes, statistics, and data types. When data types don’t match between query parameters and table columns, SQL Server performs implicit conversions according to data type precedence rules. These conversions can render indexes non-sargable (unable to be used for efficient seeks), forcing expensive scans. For example, comparing a VARCHAR column against an NVARCHAR parameter causes SQL Server to convert all VARCHAR values to NVARCHAR before comparison, preventing index usage regardless of available indexes. Addressing data type mismatches directly resolves the root cause.

A) is incorrect because increasing the database service tier provides more CPU, memory, and I/O resources but doesn’t address the root cause of inefficient query execution due to implicit conversions. While higher tiers might make poorly performing queries complete faster through brute-force resources, this approach is cost-inefficient and doesn’t solve the underlying problem. The query would still perform unnecessary conversions and table scans, wasting resources even in a higher tier. Proper query optimization should precede scaling decisions. Throwing hardware at inefficient queries is expensive and doesn’t fix the fundamental code issue.

B) is correct because modifying the query to use explicit data type matching eliminates implicit conversions, allowing SQL Server to use appropriate indexes and execute queries efficiently. If a column is VARCHAR but the query parameter is NVARCHAR, casting the parameter to VARCHAR or using a VARCHAR variable eliminates the conversion. Similarly, if comparing an INT column against a VARCHAR value, explicitly casting the VARCHAR to INT or using an INT parameter resolves the issue. This targeted fix addresses the root cause, enables index usage, and restores optimal query performance without additional cost. Data type mismatches are code-level issues requiring code-level solutions.

C) is incorrect because while automatic tuning provides valuable performance optimizations like index creation and plan forcing, it cannot fix implicit data type conversion issues which are query design problems. Automatic tuning works with existing query structures to optimize execution through indexes and plan management, but it cannot rewrite queries to use correct data types. Data type conversions are embedded in query logic and require code changes. Automatic tuning addresses certain performance patterns but doesn’t substitute for proper query development practices and data type discipline.

D) is incorrect because creating a covering index, while potentially beneficial for other scenarios, cannot resolve performance issues caused by implicit data type conversions. When implicit conversions occur, SQL Server cannot efficiently use indexes regardless of how comprehensive they are, because the conversion must be applied to every row before comparison. A covering index on all columns is expensive to maintain and wouldn’t address the core problem. Even perfect indexes become ineffective when queries include non-sargable predicates due to type conversions. Index creation should follow query optimization, not precede it.

Identifying implicit conversion issues requires analyzing execution plans looking for CONVERT_IMPLICIT operators or warnings, reviewing actual execution plan properties, and using Query Store or DMVs to identify expensive queries. Best practices include maintaining consistent data types between application parameters and database columns, using parameterized queries with appropriate types, and conducting code reviews to catch type mismatches during development rather than production troubleshooting.