@Explain(displayName = "column names", explainLevels = { Level.USER, Level.DEFAULT, Level.EXTENDED })
  public List<String> getColumnNames() {
    return columnNames;
  }
DDL task description for CREATE TEMPORARY MACRO commands.
ql/src/java/org/apache/hadoop/hive/ql/ddl/function/macro/create/CreateMacroDesc.java