Pre-checks and restrictions

Please note the following restrictions when using the data sync service.

Data Synchronization

Pre-check description

Check Item	Content
Target Database Connectivity Check	Check if the target database can be connected
Target Database Schema and Table Check	Check whether there is a schema or table with the same name as the data to be migrated in the target database There should be no Schema and Table to be synchronized during full + incremental synchronization The schema and table to be synchronized should already exist when only incremental sync
Source Database binlog_format Check	Check the source database binlog_format is ROW
Source Database binlog Enable Check	Check if the source database enables binlog
Source Database binlogRowImage Check	Check if the source database binlog_row_image is FULL
Source Database Connectivity Check	Check if the source database can be connected
Source Database Permission Check	Check if the source database account can meet migration requirements
Source Database Schema Existence Check	Check whether there is a schema to be migrated in the source database
Source Database server_id Check	Check if the source database server_id is greater than 1
Source Database Table Existence Check	Check if Table to be migrated exists in the source database
Source Database Table External Key Check	Check if the external key exists in the source database that only can be migrated without the external key
Database Version Check	Check if the version of source database version and target database can meet migration requirements

Restrictions

Sync type

• Full sync (excluding stored procedures, functions and Event)
• Full sync + incremental sync

Character sets supported

• utf8
• utf8mb4
• ascii
• binary
• latin1

DDL restrictions

• DROP statement out of sync

Supported store engines

• InnoDB
• Myisam

Foreign key constraints are not supported

Disaster recovery sync

Pre-check description

Check Item	Content
Cloud Database Status Check	Check whether the status of the source database and the target database meets the migration requirements
Cloud Database Sync Task Existence Check	Check whether a disaster recovery synchronization task already exists in the source database and the target database
Cloud Database Type Check	Check whether the type of the source database and the target database meets the migration requirements
Target Database Connectivity Check	Check if the target database can be connected
Source Database Connectivity Check	Check if the source database can be connected
Database Version Check	Check if the version of source database version and target database can meet migration requirements

Restrictions

• The source database must be the master and backup instance of the cloud database.
• The target database must be a disaster recovery instance of the cloud database.
• The data version of the source database and the target database must be the same.