flink1.10的ddl的双流窗口join，把程序重启后出现了问题

我是用flink1.10的ddl的双流窗口join，但是当我新增字段或修改字段类型，把程序重启后，无论是从savepoint处还是checkpoint处重启都是失败，最后只能删除掉checkpoint或savepoint才能使用，但是这样会丢些数据，请问该怎么处理，非常感谢？

报错如下： Caused by: org.apache.flink.util.FlinkException: Could not restore keyed state backend for KeyedProcessOperator_33601e3dd532edccff92bfce124910c6_(1/3) from any of the 1 provided restore options. at org.apache.flink.streaming.api.operators.BackendRestorerProcedure.createAndRestore(BackendRestorerProcedure.java:135) at org.apache.flink.streaming.api.operators.StreamTaskStateInitializerImpl.keyedStatedBackend(StreamTaskStateInitializerImpl.java:304) at org.apache.flink.streaming.api.operators.StreamTaskStateInitializerImpl.streamOperatorStateContext(StreamTaskStateInitializerImpl.java:131) ... 9 common frames omitted Caused by: org.apache.flink.runtime.state.BackendBuildingException: Caught unexpected exception. at org.apache.flink.contrib.streaming.state.RocksDBKeyedStateBackendBuilder.build(RocksDBKeyedStateBackendBuilder.java:336) at org.apache.flink.contrib.streaming.state.RocksDBStateBackend.createKeyedStateBackend(RocksDBStateBackend.java:548) at org.apache.flink.streaming.api.operators.StreamTaskStateInitializerImpl.lambda$keyedStatedBackend$1(StreamTaskStateInitializerImpl.java:288) at org.apache.flink.streaming.api.operators.BackendRestorerProcedure.attemptCreateAndRestore(BackendRestorerProcedure.java:142) at org.apache.flink.streaming.api.operators.BackendRestorerProcedure.createAndRestore(BackendRestorerProcedure.java:121) ... 11 common frames omitted Caused by: org.apache.flink.util.StateMigrationException: The new key serializer must be compatible. at org.apache.flink.contrib.streaming.state.restore.AbstractRocksDBRestoreOperation.readMetaData(AbstractRocksDBRestoreOperation.java:194) at org.apache.flink.contrib.streaming.state.restore.RocksDBFullRestoreOperation.restoreKVStateMetaData(RocksDBFullRestoreOperation.java:180) at org.apache.flink.contrib.streaming.state.restore.RocksDBFullRestoreOperation.restoreKeyGroupsInStateHandle(RocksDBFullRestoreOperation.java:167) at org.apache.flink.contrib.streaming.state.restore.RocksDBFullRestoreOperation.restore(RocksDBFullRestoreOperation.java:151) at org.apache.flink.contrib.streaming.state.RocksDBKeyedStateBackendBuilder.build(RocksDBKeyedStateBackendBuilder.java:279) ... 15 common frames omitted*来自志愿者整理的FLINK邮件归档