public WriterOptions inspector(ObjectInspector value) {
      this.inspector = value;
      if (!explicitSchema) {
        super.setSchema(OrcInputFormat.convertTypeInfo(
            TypeInfoUtils.getTypeInfoFromObjectInspector(value)));
      }
      return this;
    }
A required option that sets the object inspector for the rows. If
setSchema is not called, it also defines the schema.
ql/src/java/org/apache/hadoop/hive/ql/io/orc/OrcFile.java