private boolean isField(String col) {
    for (FieldSchema field : getCols()) {
      if (field.getName().equals(col)) {
        return true;
      }
    }
    return false;
  }
Marker SemanticException, so that processing that allows for table validation failures
and appropriately handles them can recover from these types of SemanticExceptions
ql/src/java/org/apache/hadoop/hive/ql/metadata/Table.java