Some doubts about ORC:
*1- hive.exec.orc.default.buffer.size* is used for read or write? *2- orc.stripe.size* is compressed or uncompresed? *3- orc.stripe.size* must be multiple of HDFS block size? 4- For read ORC file , the numbers of mappers depends onr HDFS blocks or Stripe number? *5- hive.exec.orc.split.strategy *is used for read?
