Updated on 2026-06-30 GMT+08:00

Before You Start

MgC cannot migrate data of the DATETIME type from MaxCompute. Before the migration, you need to convert such data to the STRING format.
MgC cannot migrate data of the VARCHAR or CHAR type from MaxCompute. Before the migration, you need to convert such data to the STRING format.
MgC cannot migrate metadata of transaction tables (those with the transactional=true field in DDL statements).
The TIMESTAMP_NTZ type of data in MaxCompute is not supported by the Alibaba Cloud SDK. As a result, the metadata of involved tables will fail to be migrated.
When partition data is migrated repeatedly, if the error message "Do not support update partition SerDeInfo for DLI table" is displayed, you need to manually delete the partition data from DLI and then migrate the data again.
MgC allows you to narrow the migration scope to specific partitions in MaxCompute using a template. You must enter the names of involved tables in the Excel template in lowercase letters, as MaxCompute converts table names to lowercase during table creation. If the table names in the Excel template are in uppercase, the migration will fail as the tables cannot be recognized.

CSV template editing
When you use the CSV template file provided by MgC to filter data, do not use Excel to edit the file. The file edited and saved in Excel cannot be identified by MgC.

The uploaded CSV file cannot exceed 240 KB.
DLI connection selection
Migrating metadata and data requires different DLI connections. Migrating metadata requires a DLI connection with a SQL queue configured, while migrating data requires a DLI connection with a general-purpose queue configured. If an incorrect connection is configured for a migration task, the migration task will fail.
Metadata migration and database count constraints
During metadata migration, MgC automatically creates the corresponding databases in DLI based on the number of identified source databases. For full database migrations, typically only a single database is created, whereas table-level migrations may require creating multiple databases. The system-defined upper limit for the number of databases in DLI is typically 10. Insufficient capacity or exceeding this limit will cause metadata migration failuers. Prior to initiating metadata migration, evaluate the total count of source databases to ensure that DLI has adequate quota and capacity to accommodate the new databases.