Relational Database for Online Transaction Processing (OLTP)

C

Azure SQL Database is relational database and a managed service.

Incorrect Answers:

A, B: Cosmos DB, HDInsight are non-relational databases.

D: Azure Synapse Analytics is for data warehousing, not for Online Transaction Processing

The correct answer is C. Azure SQL Database.

Explanation:

When deploying a SaaS application that requires a relational database for Online Transaction Processing (OLTP), Azure SQL Database is the recommended Azure service to use.

Azure SQL Database is a fully managed relational database service that is built on the SQL Server engine. It provides scalable and high-performance database capabilities with built-in security and compliance features.

Using Azure SQL Database can simplify database management tasks, as it eliminates the need for you to manage and maintain the underlying infrastructure. It also provides automatic backups and disaster recovery options, so you can focus on developing your application instead of worrying about database management.

Option A, Azure Cosmos DB, is a globally distributed, multi-model database service designed for NoSQL workloads. It is a good fit for applications that require high availability and low latency, but it is not specifically designed for OLTP workloads.

Option B, Azure HDInsight, is a fully managed cloud service that makes it easy to process big data using popular open-source frameworks such as Hadoop, Spark, and Hive. It is designed for big data processing and analytics workloads, not OLTP workloads.

Option D, Azure Synapse Analytics, is a cloud-based analytics service that provides a unified experience for data ingestion, big data processing, and data warehousing. It is designed for analytics and reporting workloads, not OLTP workloads.

In conclusion, for SaaS applications that require a relational database for OLTP, Azure SQL Database is the most appropriate Azure service to use.