AvroTable.java

  @Override
  public RelDataType getRowType(RelDataTypeFactory relDataTypeFactory) {
    JavaTypeFactory typeFactory = (JavaTypeFactory) relDataTypeFactory;

    List<Pair<String, RelDataType>> ret = schema.getFields().stream().map(field -> {
      Schema.Type avroFieldType = field.schema().getType();
      if (avroFieldType == Schema.Type.UNION) {
        avroFieldType = getAvroNullableField(field);
      }
      RelDataType relDataType = AvroFieldType.of(avroFieldType).toType(typeFactory);
      return new Pair<>(field.name().toUpperCase(), relDataType);
    }).collect(Collectors.toList());
    return relDataTypeFactory.createStructType(ret);
  }