private static AlterTableExecuteDesc getDeleteOrphanFilesDesc(TableName tableName, Map<String, String> partitionSpec,
      List<Node> children) throws SemanticException {

    long time = System.currentTimeMillis() - TimeUnit.DAYS.toMillis(3);
    if (children.size() == 2) {
      time = getTimeStampMillis((ASTNode) children.get(1));
    }
    AlterTableExecuteSpec spec = new AlterTableExecuteSpec(DELETE_ORPHAN_FILES, new DeleteOrphanFilesDesc(time));
    return new AlterTableExecuteDesc(tableName, partitionSpec, spec);
  }
Analyzer for ALTER TABLE ... EXECUTE commands.
ql/src/java/org/apache/hadoop/hive/ql/ddl/table/execute/AlterTableExecuteAnalyzer.java