public static Path getPlanPath(Configuration conf) {
    String plan = HiveConf.getVar(conf, HiveConf.ConfVars.PLAN);
    if (plan != null && !plan.isEmpty()) {
      return new Path(plan);
    }
    return null;
  }
Returns the Map or Reduce plan
Side effect: the BaseWork returned is also placed in the gWorkMap
@param conf
@param name
@return BaseWork based on the name supplied will return null if name is null
@throws RuntimeException if the configuration files are not proper or if plan can not be loaded
ql/src/java/org/apache/hadoop/hive/ql/exec/Utilities.java