Item | Physical protocol gateway-based migration | Logical data migration |
Migration principle | The native physical backup protocol is used to write data to the destination database as data blocks. | The JDBC protocol is used to obtain SQL statements and write the statements to the destination database. |
Operating system | Only SQL Server on Windows is supported. The version of the desktop operating system cannot be earlier than Windows XP. The version of the server operating system cannot be earlier than Windows Server 2003. | Unlimited. |
Deployment | A physical protocol gateway must be installed on the server on which the database resides. | You do not need to install a gateway. |
Network connectivity | The server on which the self-managed database is deployed can connect to the network of Alibaba Cloud. | The port to connect to the database must be enabled, or leased line-based connections must be established. |
Source database permissions | The sysadmin role is required. | The SELECT permission is required for schema migration and full migration. The sysadmin permission is required for incremental migration. For more information, see Permissions required for database accounts. |
Destination database version | The engine version of the destination database must be the same or later than the engine version of the source database. | You can migrate data from a source database that runs an engine version later than or earlier than the engine version of the destination database. |
Destination database accessibility | The destination database is inaccessible during data migration. | You can read data from or write data to the destination database during data migration. |
Limits on tables that can be migrated from the source database | Memory tables cannot be migrated. Fields of the FileStream and FileTables types cannot be migrated. | For more information, see Migrate data from a self-managed SQL Server database to an ApsaraDB RDS for SQL Server instance. |
Migration scenarios | Data can be migrated from self-managed databases to the cloud. Note The self-managed SQL Server databases can reside on ECS instances, in data centers, or on third-party cloud servers. | Data can be migrated from self-managed databases or cloud-hosted databases to the cloud. |
Migration efficiency | High. | Medium. |
Data processing extract, transform, load (ETL) | Not supported. | Supported. |
Table-level data filtering | Not supported. | Supported. |
Database-level data filtering | Supported. | Supported. |