Help Center/ Data Replication Service/ Troubleshooting/ Troubleshooting/ Failure Cases/ Real-Time Migration and Synchronization from MySQL to MySQL/ Full Phase Error: Incorrect prefix key; the used key part isn't a string, the used length is longer than the key part, or the storage engine doesn't support unique prefix keys
Updated on 2025-07-21 GMT+08:00
View PDF

Full Phase Error: Incorrect prefix key; the used key part isn't a string, the used length is longer than the key part, or the storage engine doesn't support unique prefix keys

Scenarios

During a full migration or synchronization, an error is reported, and the log information is as follows: service DATAMOVE failed, cause by: retry structures failed events=the fail structures are [type=constraint_data, index=106, schema_name= %s, object_name= %s]reason:[Incorrect prefix key; the used key part isn't a string, the used length is longer than the key part, or the storage engine doesn't support unique prefix keys]

Possible Causes

Table structures in the source and destination databases are inconsistent.

Solution

  1. Contact the O&M engineers to change the table structure of the destination database to be the same as that of the source database.
  2. In the task list, locate the target task and click Resume in the Operation column to resume the task.