hive query optimization

[abhiTowson cal]

Hi all,

Some queries in hive are executing for too long.So i have overriden
some parameters in hive, for some querys performance increased rapidly
when i overriden this properities  for some querys no change in
performance.Can any one you
tell me any other optimizations in hive apart from partitions and
buckets,

set io.sort.mb=512;
set io.sort.factor=100;
set mapred.reduce.parallel.copies=40;
set hive.map.aggr =true;
set hive.exec.parallel=true;
set hive.groupby.skewindata=true;
set mapred.job.reuse.jvm.num.tasks=-1;

default values were

io.sort.mb=256;
io.sort.factor=10;
mapred.reduce.parallel.copies=10;

Thanks
Abhishek