{"record":{"id":"640188a6e11628e3","repo":"apache/flink","slug":"type-information-for-left-input-of-type-is-not","errorCode":null,"errorMessage":"Type information for left input of type {} is not supported. Could not generate a comparator.","messagePattern":"Type information for left input of type (.+?) is not supported\\. Could not generate a comparator\\.","errorType":"exception","errorClass":"RuntimeException","httpStatus":null,"severity":"error","filePath":"flink-core/src/main/java/org/apache/flink/api/common/operators/base/InnerJoinOperatorBase.java","lineNumber":120,"sourceCode":"        TypeSerializer<IN2> rightSerializer =\n                rightInformation.createSerializer(executionConfig.getSerializerConfig());\n\n        TypeComparator<IN1> leftComparator;\n        TypeComparator<IN2> rightComparator;\n\n        if (leftInformation instanceof AtomicType) {\n            leftComparator =\n                    ((AtomicType<IN1>) leftInformation).createComparator(true, executionConfig);\n        } else if (leftInformation instanceof CompositeType) {\n            int[] keyPositions = getKeyColumns(0);\n            boolean[] orders = new boolean[keyPositions.length];\n            Arrays.fill(orders, true);\n\n            leftComparator =\n                    ((CompositeType<IN1>) leftInformation)\n                            .createComparator(keyPositions, orders, 0, executionConfig);\n        } else {\n            throw new RuntimeException(\n                    \"Type information for left input of type \"\n                            + leftInformation.getClass().getCanonicalName()\n                            + \" is not supported. Could not generate a comparator.\");\n        }\n\n        if (rightInformation instanceof AtomicType) {\n            rightComparator =\n                    ((AtomicType<IN2>) rightInformation).createComparator(true, executionConfig);\n        } else if (rightInformation instanceof CompositeType) {\n            int[] keyPositions = getKeyColumns(1);\n            boolean[] orders = new boolean[keyPositions.length];\n            Arrays.fill(orders, true);\n\n            rightComparator =\n                    ((CompositeType<IN2>) rightInformation)\n                            .createComparator(keyPositions, orders, 0, executionConfig);\n        } else {\n            throw new RuntimeException(","sourceCodeStart":102,"sourceCodeEnd":138,"githubUrl":"https://github.com/apache/flink/blob/2f3c205e9266cb30240eb7f4fdab15cad629a70f/flink-core/src/main/java/org/apache/flink/api/common/operators/base/InnerJoinOperatorBase.java#L102-L138","documentation":"Error \"Type information for left input of type {} is not supported. Could not generate a comparator.\" thrown in apache/flink.","triggerScenarios":"Triggered at runtime when the operation fails because: Type information for left input of type the reported value is not supported. Could not generate a comparator.","commonSituations":"Commonly caused by misconfiguration, missing dependencies or files, unsupported types or operations, or invalid user input leading to: Type information for left input of type the reported value is not supported. Could not generate a comparator.","solutions":["Address the cause reported by the error message: Type information for left input of type the reported value is not supported. Could not generate a comparator.","Verify the inputs, configuration values, and classpath/dependency setup related to this operation, then retry."],"exampleFix":"Correct the condition described (\"Type information for left input of type the reported value is not supported. Could not generate a comparator.\") and rerun the job or command.","handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"2f3c205e9266cb30240eb7f4fdab15cad629a70f","analyzedAt":"2026-08-14T08:48:24.518Z","schemaVersion":2},"datasetVersion":"2026-08-14T10:17:34.591Z"}