Azure SQL Database Interview Questions and Answers for 5 years experience

0
Azure SQL Database Interview Questions

  1. What are the different service tiers available in Azure SQL Database? Explain the key differences between them.

    • Answer: Azure SQL Database offers various service tiers like Basic, Standard, General Purpose, Business Critical, and Hyperscale. These tiers differ primarily in compute, storage, and I/O capabilities. Basic is the most cost-effective but least performant, suitable only for light workloads. Standard offers a balance of cost and performance. General Purpose is versatile and suitable for a wide range of applications. Business Critical provides the highest performance and availability with guaranteed uptime SLAs and high I/O throughput. Hyperscale is designed for massive scale and handles extremely large databases with elastic scalability.

  2. Explain the concept of elastic pools in Azure SQL Database. When would you use them?

    • Answer: Elastic pools are a resource grouping mechanism that allows you to allocate a specific amount of compute resources (DTUs or vCores) to a group of databases. This enables efficient resource sharing among multiple databases, which is ideal when dealing with numerous databases with fluctuating workloads. Using elastic pools is cost-effective as you pay for the pooled resources rather than individual database resources. It's beneficial when you have many databases with varying resource demands, avoiding the need to over-provision individual databases.

  3. Describe different deployment models for Azure SQL Database.

    • Answer: Azure SQL Database offers two main deployment models: Single databases and managed instances. Single databases are the traditional model, ideal for smaller applications. Managed instances provide a near-parity experience with on-premises SQL Server, suitable for large or complex migration scenarios needing minimal code changes. They also offer more control over configurations.

  4. How does Azure SQL Database handle high availability and disaster recovery?

    • Answer: Azure SQL Database provides high availability and disaster recovery through features like automatic failover, geo-replication, and read replicas. Automatic failover ensures minimal downtime in case of hardware failures. Geo-replication enables replication to a secondary region for disaster recovery and low-latency access to data in other regions. Read replicas provide scalability for read-heavy workloads while offloading the primary database.

  5. What are Azure SQL Database's security features?

    • Answer: Azure SQL Database offers robust security features like Azure Active Directory integration for authentication, Always Encrypted for encrypting sensitive data at rest and in transit, row-level security (RLS) for access control, dynamic data masking to obfuscate sensitive data, threat detection to monitor for suspicious activities, and network security features like virtual networks and firewalls to control access to the database.

  6. Explain the concept of DTUs and vCores in Azure SQL Database. What are the differences and when would you choose one over the other?

    • Answer: DTUs (Database Transaction Units) are a performance metric that represents a bundled measure of compute, memory, and I/O. vCores (virtual cores) represent dedicated compute resources, providing more granular control and scalability. DTUs are simpler to understand and manage, suitable for smaller databases and predictable workloads. vCores offer better scalability and control for large databases with fluctuating or complex workloads and allow more fine-grained performance tuning. vCore-based purchasing is generally preferred for better control and predictability, especially in larger-scale deployments.

  7. How do you monitor the performance of an Azure SQL Database? What tools and metrics would you use?

    • Answer: Azure SQL Database performance can be monitored using several tools like Azure Monitor, SQL Server Management Studio (SSMS), and Azure portal dashboards. Key metrics to track include CPU utilization, memory usage, I/O wait statistics, execution plan statistics, query performance, and wait statistics. You'd also utilize tools like Query Store and Extended Events for in-depth analysis of query performance and identifying bottlenecks.

  8. Describe different backup and restore strategies for Azure SQL Database.

    • Answer: Azure SQL Database offers several backup strategies, including automated backups (managed by Azure), point-in-time restore (PITR), and full database backups. Automated backups offer a basic level of recovery, while PITR allows restoring to a specific point in time within a retention window. Full backups provide a complete snapshot of the database at a given point. The choice depends on the Recovery Point Objective (RPO) and Recovery Time Objective (RTO) requirements of the application.

Thank you for reading our blog post on 'Azure SQL Database Interview Questions and Answers for 5 years experience'.We hope you found it informative and useful.Stay tuned for more insightful content!