{"record":{"id":"35dedc298b4d0512","repo":"pathwaycom/pathway","slug":"only-unchanged-columns-of-an-input-tables-can-be-u","errorCode":null,"errorMessage":"Only unchanged columns of an input tables can be used in input synchronization groups","messagePattern":"Only unchanged columns of an input tables can be used in input synchronization groups","errorType":"exception","errorClass":"ValueError","httpStatus":null,"severity":"error","filePath":"python/pathway/io/_synchronization.py","lineNumber":298,"sourceCode":"            if (\n                not isinstance(node, InputOperator)\n                or not isinstance(node.datasource, GenericDataSource)\n                or node.outputs[0].value != column._table\n            ):\n                continue\n            is_table_found = True\n            group = api.ConnectorGroupDescriptor(\n                name, column_idx, max_difference, priority, idle_duration\n            )\n            if node.datasource.data_source_options.synchronization_group is not None:\n                raise ValueError(\n                    \"Only one column from a table can be used in a synchronization group\"\n                )\n            node.datasource.data_source_options.set_synchronization_group(group)\n            break\n\n        if not is_table_found:\n            raise ValueError(\n                \"Only unchanged columns of an input tables can be used in input synchronization groups\"\n            )\n\n    if len(column_types) > 1:\n        raise ValueError(\n            \"All synchronization group column types must coincide. \"\n            \"However several types have been detected: {}\".format(\n                \", \".join(sorted([f\"'{t}'\" for t in column_types]))\n            )\n        )\n\n\ndef _check_column_type(column, max_difference):\n    column_type = column._column.dtype\n    if column_type not in _SUPPORTED_COLUMN_DTYPES:\n        raise ValueError(\n            f\"Fields of type {column_type.typehint} are not supported in connector groups\"\n        )","sourceCodeStart":280,"sourceCodeEnd":316,"githubUrl":"https://github.com/pathwaycom/pathway/blob/fa2f74a4649b7c5908690cf60137263d8d80de5f/python/pathway/io/_synchronization.py#L280-L316","documentation":"Error \"Only unchanged columns of an input tables can be used in input synchronization groups\" thrown in pathwaycom/pathway.","triggerScenarios":"Thrown at python/pathway/io/_synchronization.py:298 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Pass only plain, unchanged input columns (e.g. the columns read directly from the connector) to the synchronization group; do not pass computed or filtered columns."],"exampleFix":"pw.io.register_input_synchronization_group(t.time_col, max_difference=timedelta(seconds=5))","handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"fa2f74a4649b7c5908690cf60137263d8d80de5f","analyzedAt":"2026-08-15T01:48:17.006Z","schemaVersion":2},"datasetVersion":"2026-08-15T22:17:37.221Z"}