Business Central's underlying database in Azure is not a NoSQL database.

 Business Central's underlying database in Azure is not a NoSQL database. It is a relational database using the SQL Server database engine. While Business Central utilizes various cloud services like Azure SQL Database, these services still provide a relational database infrastructure. 

Here's why: 

• SQL Server Engine:

  Business Central relies on the SQL Server database engine, which is a foundation for relational databases.
• Relational Data Model:

  Relational databases, like SQL Server, store data in tables with rows and columns, which is the standard approach for structured data.
• Azure SQL Database:

  Azure SQL Database is a managed SQL Server database service in Azure, offering a fully managed relational database platform for various use cases.

While Azure offers NoSQL database options like Azure Cosmos DB, Business Central is not designed to use them as its primary database.