为提高效率，提问时请尽量提供详细背景信息，问题描述清晰可优先响应。以下信息点请尽量提供：
- 【系统版本 & kernel 版本】
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
172.31.90.50 Ready <none> 142d v1.14.1 172.31.90.50 <none> Red Hat Enterprise Linux 8.0 (Ootpa) 4.18.0-80.el8.x86_64 docker://18.6.2
172.31.90.53 Ready <none> 120d v1.14.1 172.31.90.53 <none> Red Hat Enterprise Linux 8.0 (Ootpa) 4.18.0-80.el8.x86_64 docker://18.6.2
172.31.90.56 Ready <none> 120d v1.14.1 172.31.90.56 <none> Red Hat Enterprise Linux 8.0 (Ootpa) 4.18.0-80.el8.x86_64 docker://18.6.2
- 【TiDB 版本】 5.7.25-TiDB-v3.0.1 MySQL Community Server (Apache License 2.0)
- 【磁盘型号】 普通机械盘
- 【集群节点分布】
haodai-pd-0 1/1 Running 1 3d20h 10.21.56.214 172.31.90.56 <none> <none>
haodai-pd-1 1/1 Running 0 3d20h 10.11.10.64 172.31.90.53 <none> <none>
haodai-pd-2 1/1 Running 0 3d20h 10.11.15.97 172.31.90.50 <none> <none>
haodai-tidb-0 2/2 Running 0 3d20h 10.11.15.100 172.31.90.50 <none> <none>
haodai-tidb-1 2/2 Running 0 3d20h 10.21.56.217 172.31.90.56 <none> <none>
haodai-tikv-0 1/1 Running 0 3d20h 10.11.15.99 172.31.90.50 <none> <none>
haodai-tikv-1 1/1 Running 0 3d20h 10.21.56.216 172.31.90.56 <none> <none>
haodai-tikv-2 1/1 Running 0 3d20h 10.11.10.66 172.31.90.53 <none> <none>
- 【数据量 & region 数量 & 副本数】 500G 1850 3
- 【问题描述（我做了什么）】 上游是oracle MySQL,使用pt-osc改表时下游的dm报错, 报错信息如下
[code=10006:class=database:scope=downstream:level=high] execute statement failed: ALTER TABLE `database`.`_tablename_new` CHANGE COLUMN `y_sign` `virtual_phone` VARCHAR(15) NOT NULL DEFAULT '' COMMENT '关联的虚拟号': Error 1105: unsupported modify charset from binary to utf8
github.com/pingcap/dm/pkg/terror.(*Error).Delegate
/home/jenkins/workspace/build_dm_master/go/src/github.com/pingcap/dm/pkg/terror/terror.go:267
github.com/pingcap/dm/pkg/baseconn.(*BaseConn).ExecuteSQLWithIgnoreError
/home/jenkins/workspace/build_dm_master/go/src/github.com/pingcap/dm/pkg/baseconn/conn.go:179
github.com/pingcap/dm/syncer.(*Conn).executeSQLWithIgnore.func2
/home/jenkins/workspace/build_dm_master/go/src/github.com/pingcap/dm/syncer/db.go:178
github.com/pingcap/dm/pkg/retry.(*FiniteRetryStrategy).Apply
/home/jenkins/workspace/build_dm_master/go/src/github.com/pingcap/dm/pkg/retry/strategy.go:71
github.com/pingcap/dm/pkg/baseconn.(*BaseConn).ApplyRetryStrategy
/home/jenkins/workspace/build_dm_master/go/src/github.com/pingcap/dm/pkg/baseconn/conn.go:200
github.com/pingcap/dm/syncer.(*Conn).executeSQLWithIgnore
/home/jenkins/workspace/build_dm_master/go/src/github.com/pingcap/dm/syncer/db.go:173
github.com/pingcap/dm/syncer.(*Syncer).sync
/home/jenkins/workspace/build_dm_master/go/src/github.com/pingcap/dm/syncer/syncer.go:932
github.com/pingcap/dm/syncer.(*Syncer).Run.func3
/home/jenkins/workspace/build_dm_master/go/src/github.com/pingcap/dm/syncer/syncer.go:1068
runtime.goexit
/usr/local/go/src/runtime/asm_amd64.s:1337
- 【关键词】 DM OSC DDL 兼容性