Box 1: The requirement to support cross-database queries is a key differentiator. Azure SQL Managed Instance supports cross-database queries natively (using standard T-SQL), whereas Azure SQL Database (Singleton) does not support them in the same way (requiring Elastic Query). Furthermore, the JSON schema includes properties specific to Managed Instances, such as subnetId, vCores, and licenseType. A logical server (Microsoft.Sql/servers) does not utilize subnetId or vCores at the top level; those are properties of the instance or database.

Box 2: The resource includes a subnetId property which references a subnet within a Virtual Network. In Azure Resource Manager (ARM) templates, if a resource (the Managed Instance) depends on another resource (the Virtual Network) created within the same template to establish its networking configuration, it must explicitly define that dependency in the dependsOn array. Therefore, the instance depends on [parameters('virtualNetworkName')]. It cannot depend on targetName because that is the name of the instance itself (circular dependency).

Microsoft.Sql managedInstances - Bicep, ARM template & Terraform AzAPI reference | Microsoft Learn

Reference: Lists the valid properties for Microsoft.Sql/managedInstances, confirming that subnetId, vCores, storageSizeInGB, and licenseType are top-level properties for this resource type.

URL: https://learn.microsoft.com/en-us/azure/templates/microsoft.sql/managedinstances?pivots=deployment-language-arm-template

Run cross-database queries on Azure SQL Managed Instance | Microsoft Learn

Reference: "Azure SQL Managed Instance supports cross-database queries. This functionality allows you to query data from one database and use it in another database."

URL: https://learn.microsoft.com/en-us/azure/azure-sql/managed-instance/cross-database-queries-overview?view=azuresql

Define the order for deploying resources in ARM templates | Microsoft Learn

Reference: "When you deploy resources, you may need to make sure some resources exist before others... You use the dependsOn element to specify a dependency."

URL: https://learn.microsoft.com/en-us/azure/azure-resource-manager/templates/resource-dependency