public void collectStatsFromAggregator(IStatsGatherDesc conf) {
    // AggKey in StatsWork is used for stats aggregation while StatsAggPrefix
    // in FileSinkDesc is used for stats publishing. They should be consistent.
    basicStatsWork.setAggKey(conf.getStatsAggPrefix());
    basicStatsWork.setStatsTmpDir(conf.getTmpStatsDir());
    basicStatsWork.setStatsReliable(statsReliable);
  }
Stats Work, may include basic stats work and column stats desc
ql/src/java/org/apache/hadoop/hive/ql/plan/StatsWork.java