Custom setting of MapReduce tasks in HIVE

Question

Hi,

I tried to set custom map reduce tasks to 4, but when i run the hive script it shows only 1 map task is being executed at the log. Could you please correct me if i went wrong in any case?

Answer 1

When we set number of mappers to 4 it doesn't necessarily mean that the task will use 4 mappers if not required.Think of it as a max number of mappers to be used for a task.

You have set the minimum number of mappers in hive configuration files to reflect the changes in hive console. I hope this information is helpful.