flinksql 添加字段从checkpoint重启的问题

flinksql 在group by添加字段后，从checkpoint重启会报错，

2022-02-07 18:28:33
java.lang.Exception: Exception while creating StreamOperatorStateContext.
	at org.apache.flink.streaming.api.operators.StreamTaskStateInitializerImpl.streamOperatorStateContext(StreamTaskStateInitializerImpl.java:254)
	at org.apache.flink.streaming.api.operators.AbstractStreamOperator.initializeState(AbstractStreamOperator.java:272)
	at org.apache.flink.streaming.runtime.tasks.OperatorChain.initializeStateAndOpenOperators(OperatorChain.java:441)
	at org.apache.flink.streaming.runtime.tasks.StreamTask.restoreGates(StreamTask.java:582)
	at org.apache.flink.streaming.runtime.tasks.StreamTaskActionExecutor$1.call(StreamTaskActionExecutor.java:55)
	at org.apache.flink.streaming.runtime.tasks.StreamTask.executeRestore(StreamTask.java:562)
	at org.apache.flink.streaming.runtime.tasks.StreamTask.runWithCleanUpOnFail(StreamTask.java:647)
	at org.apache.flink.streaming.runtime.tasks.StreamTask.restore(StreamTask.java:537)
	at org.apache.flink.runtime.taskmanager.Task.doRun(Task.java:759)
	at org.apache.flink.runtime.taskmanager.Task.run(Task.java:566)
	at java.lang.Thread.run(Thread.java:748)
Caused by: org.apache.flink.util.FlinkException: Could not restore keyed state backend for KeyedProcessOperator_563f38a7d955da9b9b5048f28249c3bd_(3/40) from any of the 1 provided restore options.
	at org.apache.flink.streaming.api.operators.BackendRestorerProcedure.createAndRestore(BackendRestorerProcedure.java:160)
	at org.apache.flink.streaming.api.operators.StreamTaskStateInitializerImpl.keyedStatedBackend(StreamTaskStateInitializerImpl.java:345)
	at org.apache.flink.streaming.api.operators.StreamTaskStateInitializerImpl.streamOperatorStateContext(StreamTaskStateInitializerImpl.java:163)
	... 10 more
Caused by: org.apache.flink.runtime.state.BackendBuildingException: Failed when trying to restore heap backend
	at org.apache.flink.runtime.state.heap.HeapKeyedStateBackendBuilder.restoreState(HeapKeyedStateBackendBuilder.java:177)
	at org.apache.flink.runtime.state.heap.HeapKeyedStateBackendBuilder.build(HeapKeyedStateBackendBuilder.java:111)
	at org.apache.flink.runtime.state.hashmap.HashMapStateBackend.createKeyedStateBackend(HashMapStateBackend.java:131)
	at org.apache.flink.runtime.state.hashmap.HashMapStateBackend.createKeyedStateBackend(HashMapStateBackend.java:73)
	at org.apache.flink.runtime.state.StateBackend.createKeyedStateBackend(StateBackend.java:136)
	at org.apache.flink.streaming.api.operators.StreamTaskStateInitializerImpl.lambda$keyedStatedBackend$1(StreamTaskStateInitializerImpl.java:328)
	at org.apache.flink.streaming.api.operators.BackendRestorerProcedure.attemptCreateAndRestore(BackendRestorerProcedure.java:168)
	at org.apache.flink.streaming.api.operators.BackendRestorerProcedure.createAndRestore(BackendRestorerProcedure.java:135)
	... 12 more
Caused by: org.apache.flink.util.StateMigrationException: The new key serializer (org.apache.flink.table.runtime.typeutils.RowDataSerializer@4ceb3b3d) must be compatible with the previous key serializer (org.apache.flink.table.runtime.typeutils.RowDataSerializer@4ceb3b3d).
	at org.apache.flink.runtime.state.restore.FullSnapshotRestoreOperation.readMetaData(FullSnapshotRestoreOperation.java:210)
	at org.apache.flink.runtime.state.restore.FullSnapshotRestoreOperation.restoreKeyGroupsInStateHandle(FullSnapshotRestoreOperation.java:171)
	at org.apache.flink.runtime.state.restore.FullSnapshotRestoreOperation.access$100(FullSnapshotRestoreOperation.java:113)
	at org.apache.flink.runtime.state.restore.FullSnapshotRestoreOperation$1.next(FullSnapshotRestoreOperation.java:158)
	at org.apache.flink.runtime.state.restore.FullSnapshotRestoreOperation$1.next(FullSnapshotRestoreOperation.java:140)
	at org.apache.flink.runtime.state.heap.HeapSavepointRestoreOperation.restore(HeapSavepointRestoreOperation.java:115)
	at org.apache.flink.runtime.state.heap.HeapSavepointRestoreOperation.restore(HeapSavepointRestoreOperation.java:57)
	at org.apache.flink.runtime.state.heap.HeapKeyedStateBackendBuilder.restoreState(HeapKeyedStateBackendBuilder.java:174)
	... 19 more

1、可以通过在一个字段作为json打包字段做冗余，来避免从checkpoint恢复失败的问题.