Explanation
Data Transmission Service (DTS) is a real-time data streaming service that supports data transmission between data sources such as relational databases, NoSQL, and Big Data (OLAP). DTS supports data migration, data synchronization, and change data subscription scenarios. DTS can migrate your data to and from most of the widely used commercial and open source databases. It supports homogeneous migrations such as MySQL to MySQL, as well as heterogeneous migrations between different database platforms, such as Oracle to MySQL.
Migrations can be from on-premises databases to RDS or ECS, databases running on ECS to RDS, or vice versa, as well as from one RDS database to another RDS database. DTS also supports migrating data between RDS instances of different Alibaba Cloud accounts, as long as they are in the same region1. Therefore, the statement B. The data cannot be migrated is NOT correct for migrating self-built MySQL databases (running on ECS) to RDS. The other statements are correct, as the data can be imported via the Intranet, the public network, or by running mysqldump234. References:
1: Migrate Self-built Database to RDS - Alibaba Cloud
2: Migrating a Self-built MySQL Database to Alibaba Cloud RDS for MySQL with Minimal Downtime
- Alibaba Cloud Community
3: Migrating Data from a Self-Managed SQL Server Database on an ECS to an ApsaraDB RDS for SQL Server Database
4: Migrate data between RDS instances of different Alibaba Cloud accounts,Data Transmission Service