The Query Store feature in Azure Database for MySQL provides a way to track query performance over time. Query Store simplifies performance troubleshooting by helping you quickly find the longest running and most resource-intensive queries. Query Store automatically captures a history of queries and runtime statistics, and it retains them for your review. It separates data by time windows so that you can see database usage patterns. Data for all users, databases, and queries is stored in the mysql schema database in the Azure Database for MySQL instance.
Reference:
https://docs.microsoft.com/en-us/azure/mysql/concepts-query-store

Explanation:
Using ROWS_PER_BATCH with BULK INSERT helps optimize the data loading process by indicating how many rows constitute a batch. By specifying ROWS_PER_BATCH, you can improve the performance of bulk data loading operations, which is especially beneficial when adding large amounts of data at regular intervals. It can reduce the amount of logging and improve the speed of the operation by allowing SQL Server to handle data in manageable chunks.
Specifying UNIQUE with CREATE INDEX ensures that the index enforces uniqueness on the specified column(s), which is essential if you want to prevent duplicate entries in those columns.
By ensuring uniqueness, this parameter helps maintain the quality and integrity of the data in DB1, which is important for reliable database operations and queries that depend on the indexed data.

Explanation:
Box 1: 128.0
-- Connect to database
-- Database data space allocated in MB and database data space allocated unused in MB SELECT SUM(size/128.0) AS DatabaseDataSpaceAllocatedInMB, SUM(size/128.0 - CAST(FILEPROPERTY(name, 'SpaceUsed') AS int)/128.0) AS DatabaseDataSpaceAllocatedUnusedInMB FROM sys.database_files GROUP BY type_desc HAVING type_desc = 'ROWS' Box 2: sys.database_files Reference:
https://techcommunity.microsoft.com/t5/azure-database-support-blog/how-to-get-azure-sql-database-size/ba-p/369189

To ensure automatic failover without data loss if a datacenter fails, you should choose the Business Critical deployment option and the Premium pricing tier for the Azure SQL database named DB1. The Business Critical deployment option provides a 99.995% availability SLA, and the Premium pricing tier includes features such as advanced security, high availability, and business continuity. This option also offers the ability to use a failover group with multiple readable secondary replicas.

Azure SQL Database single database supports Data Sync.
Incorrect Answers:
A: Azure SQL Managed instance does not support Data Sync.
Reference:
https://docs.microsoft.com/en-us/azure/azure-sql/database/features-comparison