public void add(int orderedColumn, int valueColumn, TypeInfo typeInfo) {
    if (orderedTreeMap.containsKey(orderedColumn)) {
      throw new RuntimeException(
          name + " duplicate column " + orderedColumn +
          " in ordered column map " + orderedTreeMap.toString() +
          " when adding value column " + valueColumn + ", type into " + typeInfo.toString());
    }
    orderedTreeMap.put(orderedColumn, new Value(valueColumn, typeInfo));
  }
This class collects column information for mapping vector columns, including the hive type name.

The column information are kept ordered by a specified column.

Call getMapping to collects the results into convenient arrays.
ql/src/java/org/apache/hadoop/hive/ql/exec/vector/VectorColumnOrderedMap.java