MariaDB 到 PolarDb for MySQL

选择对端数据库：

PolarDb for MySQL

数据链路

基本功能

功能	说明
Schema Migration	If the target schema does not exist, BladePipe will automatically generate and execute CREATE statements based on the source metadata and the mapping rule.
Full Data Migration	Migrate data by sequentially scanning data in tables and writing it in batches to the target database.
Incremental Data Sync	Sync of common DML like INSERT, UPDATE, DELETE is supported.
Data Verification and Correction	Verify all existing data. Optionally, you can correct the inconsistent data based on verification results. Scheduled DataTasks are supported. For more information, see Create Verification and Correction DataJob.
Subscription Modification	Add, delete, or modify the subscribed tables with support for historical data migration. For more information, see Modify Subscription.
Position Resetting	Reset positions by file position or timestamp. Allow re-consumption of incremental data logs in a past period or since a specific Binlog file and position.
Table Name Mapping	Support the mapping rules, namely, keeping the name the same as that in Source, converting the text to lowercase, converting the text to uppercase, truncating the name by "_digit" suffix.
DDL Sync	ALTER TABLE ADD COLUMN, DROP COLUMN, MODIFY COLUMN, CHANGE COLUMN ADD INDEX RENAME TABLE CREATE TABLE (whole database sync) Table partitioning Other compatible DDL
Metadata Retrieval	Retrieve the target metadata with filtering conditions or target primary keys set from the source table.

高级功能

功能	说明
增量写入冲突策略	IGNORE: 冲突则忽略（不做写入），REPLACE: 冲突则整行替换
0 值时间处理	支持将 0 值时间设置成不同类型的值，防止写入对端报错
Online DDL Compatibility	Support GH-OST, PT-OSC, Aliyun DMS Online DDL, PT_GHOST.
Scheduled Full Data Migration	For more information, see Create Scheduled Full Data DataJob.
Custom Code	For more information, see Custom Code Processing, Debug Custom Code and Logging in Custom Code.
Data Filtering Conditions	Support data filtering using WHERE conditions, with SQL-92 as the SQL language. For more information, see Data Filtering.
Setting Target Primary Key	Change the primary key to another field to facilitate data aggregation and other operations.

限制和注意点

限制项	说明
MySQL 存储引擎	支持 InnoDB, MySIAM, 阿里云 XEngine, 其他存储引擎暂未测试
MySQL 字符集	支持 utf8, utf8mb4, latin1, 其他编码暂未测试
字符集	支持 utf8, utf8mb4, latin1, 其他编码暂未测试

链路FAQ

• MySQL 任务延迟怎么办?

• MySQL 源端找不到 binlog 文件

• 如何打开 MySQL 源端心跳?

• MySQL 源端 Schema 权限报错怎么办?

  Tips: MySQL 源端相关 FAQ 同样适用于 MySQL 系数据源。

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源端数据源

前置条件

条件	说明
账号权限	文档：MySQL / MariaDB 需要的权限
开启 Binlog	[mysqld] log-bin=mysql-bin # 开启 Binlog binlog-format=ROW # 选择 ROW 模式 binlog_row_image=FULL # 变更带所有列数据

任务参数

参数名称	说明
parseBinlogParallel	增量解析 Binlog 的并发数
parseBinlogBufferSize	用于增量解析 Binlog 的环形队列大小
maxTransactionSize	单事务最大数据条数，超过则分段刷出
limitThroughputMb	限制增量 Binlog 流量
extraDDL	兼容额外的 DDL 同步，包括 PT, GHOST, ALI_DMS, PT_GHOST
fullDataSqlConditionEnabled	将过滤条件拼入 SQL 中进行源端数据扫描，此参数只针对全量迁移有效
srcTimeZone	源端时区，例如 +08:00, Asia/Shanghai, America/New_York 等

Tips: 通用参数配置请参考 通用参数及功能

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目标端数据源

前置条件

条件	说明
账号权限	云数据库 读写 权限账号或 高权限 账号
网络准备	迁移同步节点（sidecar）可连接 PolarDbMySQL 标准交互接口（如 3306）

任务参数

参数名称	说明
keyConflictStrategy	增量写入遇到主键冲突策略: IGNORE 冲突忽略（默认） REPLACE 冲突替换（可选）
dstWholeReplace	将 INSERT 和 UPDATE 操作变成对端整行覆盖
mergeMaxInsertSize	当并行策略 mergeMaxInsertSize 为 TABLE_IMPORT_OPTIMIZE 时, 相同表单批最大合并变更数据条数(提升并行度)

Tips: 通用参数配置请参考 通用参数及功能