I managed to find the answer:
When creating an Azure Synapse Analytics resource, you need to create or use an existing ADLS Gen 2 storage account because it is required to store the metadata for the workspace. Additionally, the storage account is used to store the data for the dedicated SQL pools and serverless SQL pools.
1. An ordinary storage account cannot be used because it does not support hierarchical namespace, which is required for ADLS Gen 2. ADLS Gen 2 provides a hierarchical namespace that allows you to organize your data into a hierarchy of directories and files, which is important for big data workloads.
2. If you delete the ADLS Gen 2 storage account associated with your Synapse workspace, you will lose all the data stored in the account, including the metadata for the workspace. This will make it impossible to access the workspace and its resources. Therefore, it is important to be careful when deleting storage accounts associated with Synapse workspaces.
3, A serverless SQL pool is created by default because it provides a cost-effective way to query data stored in ADLS Gen 2 without having to provision and manage dedicated resources. It allows you to pay only for the queries you run, and it automatically scales up or down based on the workload. However, you can choose to delete the serverless SQL pool if you do not need it.
In order to use T-SQL on a storage account, hierarchical namespace needs to be enabled so that the blobs can be organized in a way that allows for easy querying of the data using T-SQL. This is not possible with an ordinary storage account (non-Gen2) due to the blob storage structure.
The metadata for the workspace is stored in the ADLS Gen2 storage account because it provides a hierarchical namespace that allows for efficient organization and management of the metadata. An ordinary storage account does not provide this feature, which is why it cannot be used to store the metadata for a Synapse workspace.
