2022-08-05 175535,290 INFO org.apache.flink.runtime.taskmanager.Task [] - Freeing task resources for Source: load-source -> Flat Map -> Sink: Writer -> Sink: Committer (1/1)#4 (7ddb98a97ab5541b802bdc0af15eb92a). 2022-08-05 175535,291 INFO org.apache.flink.runtime.taskexecutor.TaskExecutor [] - Un-registering task and sending final execution state FAILED to JobManager for task Source: load-source -> Flat Map -> Sink: Writer -> Sink: Committer (1/1)#4 7ddb98a97ab5541b802bdc0af15eb92a. 2022-08-05 175535,294 INFO org.apache.flink.runtime.executiongraph.ExecutionGraph [] - Source: load-source -> Flat Map -> Sink: Writer -> Sink: Committer (1/1) (7ddb98a97ab5541b802bdc0af15eb92a) switched from RUNNING to FAILED on 43d86452-03a7-4996-be68-d730acd13530 @ kubernetes.docker.internal (dataPort=-1). org.apache.flink.table.api.ValidationException: The UNION operation on two unbounded tables is currently not supported. at org.apache.flink.table.operations.utils.SetOperationFactory.failIfStreaming(SetOperationFactory.java:108) ~[flink-table-api-java-1.15.1.jar:1.15.1] at org.apache.flink.table.operations.utils.SetOperationFactory.create(SetOperationFactory.java:62) ~[flink-table-api-java-1.15.1.jar:1.15.1] at org.apache.flink.table.operations.utils.OperationTreeBuilder.union(OperationTreeBuilder.java:466) ~[flink-table-api-java-1.15.1.jar:1.15.1] at org.apache.flink.table.api.internal.TableImpl.union(TableImpl.java:381) ~[flink-table-api-java-1.15.1.jar:1.15.1]

My flow is: StreamSource -> FlatMapFunction {StreamTableEnvironment TableA.union(TableB)} -> StreamSink