Automatic tuning SQL Server identifies and fixes performance issues caused by query execution plan choice regressions. Automatic tuning in Azure SQL Database and SQL database in Microsoft Fabric also creates necessary indexes and drops unused indexes.
Step 1: To enable automatic tuning on a server in Azure SQL Database, navigate to the server in the Azure portal [Select sql12345678] and then select Automatic tuning in the menu.

Step 2: Select CREATE_INDEX, and change it to enabled.
Enable automatic tuning on server
On the server level, you can choose to inherit automatic tuning configuration from "Azure Defaults" or not to inherit the configuration. Azure defaults are FORCE_LAST_GOOD_PLAN enabled, CREATE_INDEX disabled, and DROP_INDEX disabled.
Step 3: Click the Apply button.
Automatic tuning options on a server are applied to all databases on this server. By default, all databases inherit configuration from their parent server, but this can be overridden and specified for each database individually.
Reference:
https://learn.microsoft.com/en-us/azure/azure-sql/database/automatic-tuning-enable

Explanation:
Box 1: CREATE EXTERNAL TABLE
An external table points to data located in Hadoop, Azure Storage blob, or Azure Data Lake Storage. External tables are used to read data from files or write data to files in Azure Storage.
With Synapse SQL, you can use external tables to read external data using dedicated SQL pool or serverless SQL pool.
Syntax:
CREATE EXTERNAL TABLE { database_name.schema_name.table_name |
schema_name.table_name | table_name }
( <column_definition> [ ,...n ] )
WITH (
LOCATION = 'folder_or_filepath',
DATA_SOURCE = external_data_source_name,
FILE_FORMAT = external_file_format_name
Box 2. OPENROWSET
When using serverless SQL pool, CETAS is used to create an external table and export query results to Azure Storage Blob or Azure Data Lake Storage Gen2.
Example:
AS
SELECT decennialTime, stateName, SUM(population) AS population FROM
OPENROWSET(BULK
'https://azureopendatastorage.blob.core.windows.net/censusdatacontainer/ release/us_population_county/year=*/*.parquet', FORMAT='PARQUET') AS [r] GROUP BY decennialTime, stateName GO Reference:
https://docs.microsoft.com/en-us/azure/synapse-analytics/sql/develop-tables-external-tables

Columnstore archive provides the maximum data compression in an Azure SQL Database when query performance is not the top priority. While columnstore compression is already highly efficient for analytical workloads, the archive option further reduces the data size, but at the cost of increased compression and decompression time.
Reference:
https://brainly.com/question/61706068

Explanation:
In T-SQL, just point to App name not managed identity.
https://learn.microsoft.com/en-us/azure/active-directory/managed-identities-azure- resources/tutorial-windows-vm-access-sql