text: set hive.map.aggr=true;
  set mapreduce.reduce.speculative=false;
  set hive.auto.convert.join=true;
  set hive.optimize.reducededuplication.min.reducer=1;
  set hive.optimize.mapjoin.mapreduce=true;
  set hive.stats.autogather=true;
  
  set mapred.reduce.parallel.copies=30;
  set mapred.job.shuffle.input.buffer.percent=0.5;
  set mapred.job.reduce.input.buffer.percent=0.2;
  set mapred.map.child.java.opts=-server -Xmx2800m -Djava.net.preferIPv4Stack=true;
  set mapred.reduce.child.java.opts=-server -Xmx3800m -Djava.net.preferIPv4Stack=true;
  set mapreduce.map.memory.mb=3072;
  set mapreduce.reduce.memory.mb=4096;
  