{"record":{"id":"fce94ea47ef68ef5","repo":"apache/beam","slug":"unsupported-vector-type-type","errorCode":null,"errorMessage":"Unsupported vector type: <type>","messagePattern":"Unsupported vector type: <type>","errorType":"exception","errorClass":"IllegalArgumentException","httpStatus":null,"severity":"error","filePath":"sdks/java/io/delta/src/main/java/org/apache/beam/sdk/io/delta/SerializableRow.java","lineNumber":286,"sourceCode":"      StructType structType = (StructType) type;\n      int numFields = structType.fields().size();\n      ColumnVector[] childFields = new ColumnVector[numFields];\n      for (int j = 0; j < numFields; j++) {\n        childFields[j] = vector.getChild(j);\n      }\n      return new SerializableRow(new VectorRow(structType, childFields, index));\n    } else if (type instanceof DateType) {\n      return vector.getInt(index);\n    } else if (type instanceof TimestampType) {\n      return vector.getLong(index);\n    } else if (type instanceof ArrayType) {\n      ArrayValue arr = vector.getArray(index);\n      return convertArray(arr, (ArrayType) type);\n    } else if (type instanceof MapType) {\n      MapValue map = vector.getMap(index);\n      return convertMap(map, (MapType) type);\n    }\n    throw new IllegalArgumentException(\"Unsupported vector type: \" + type);\n  }\n\n  private static List<@Nullable Object> convertArray(ArrayValue arr, ArrayType arrayType) {\n    int size = arr.getSize();\n    ColumnVector elements = arr.getElements();\n    DataType elementType = arrayType.getElementType();\n    List<@Nullable Object> result = new ArrayList<>(size);\n    for (int i = 0; i < size; i++) {\n      result.add(getVectorValue(elements, i, elementType));\n    }\n    return result;\n  }\n\n  private static Map<Object, @Nullable Object> convertMap(MapValue map, MapType mapType) {\n    int size = map.getSize();\n    ColumnVector keys = map.getKeys();\n    ColumnVector values = map.getValues();\n    DataType keyType = mapType.getKeyType();","sourceCodeStart":268,"sourceCodeEnd":304,"githubUrl":"https://github.com/apache/beam/blob/12126d8942aaf848030c478b4c6a28c6af861c66/sdks/java/io/delta/src/main/java/org/apache/beam/sdk/io/delta/SerializableRow.java#L268-L304","documentation":"SerializableRow.getVectorValue() converts ColumnVector entries into Java objects for the supported DataType set; an unrecognized vector DataType throws IllegalArgumentException 'Unsupported vector type: <type>'. It is the vectorized counterpart of getValue()'s unsupported-type error and is reached while converting arrays/maps/keys.","triggerScenarios":"While serializing array elements or map keys/values during processElement, a nested ColumnVector carries a Delta DataType with no conversion mapping.","commonSituations":"Nested arrays/maps containing newer Delta element types the connector doesn't support; version skew between delta kernel and the Beam Delta IO connector; tables written by newer Delta writer versions.","solutions":["Upgrade the Beam Delta IO connector and io.delta kernel dependencies to versions supporting the nested element type","Locate the offending nested column (array element or map key/value type) from the table schema","Rewrite the table casting the nested element type to a supported one","Flatten or restructure the schema (e.g. store complex values as JSON strings) if the type remains unsupported"],"exampleFix":"// before\n// map<string, unsupported_nested_type> in the table\nPCollection<Row> rows = input.apply(DeltaIO.read().withTable(path).withStartVersion(0L));\n// after\n-- rewrite the table casting the nested element type (Spark example)\ndf = spark.read.format(\"delta\").load(path).withColumn(\"m\", expr(\"map_from_entries(transform(map_entries(m), e -> (e.key, cast(e.value as string))))\"))\ndf.write.format(\"delta\").mode(\"overwrite\").save(path)","handlingStrategy":"validation","validationCode":"// Recursively check nested array/map element types for supported mappings before reading\ncheckNested(deltaSchema); // throws if any nested element/key/value DataType is unsupported","typeGuard":null,"tryCatchPattern":"try {\n  rows = input.apply(deltaIO);\n} catch (IllegalArgumentException e) {\n  if (e.getMessage().startsWith(\"Unsupported vector type:\")) {\n    // restructure nested collections to supported element types, or upgrade connector\n  } else { throw e; }\n}","preventionTips":["Keep nested array/map element types to primitives the connector supports","Test reads against a small version range when adopting tables with deep/nested schemas","Upgrade beam-sdks-java-io-delta and delta kernel together to avoid type-mapping skew"],"tags":["java","apache-beam","delta-lake","unsupported-type","serialization"],"backgroundTag":"unsupported-operation","analyzedSha":"12126d8942aaf848030c478b4c6a28c6af861c66","analyzedAt":"2026-09-13T01:50:10.254Z","contentChangedAt":"2026-09-13T01:50:10.254Z","schemaVersion":2},"datasetVersion":"2026-09-14T16:17:12.679Z"}