what is the difference between “hive.compute.splits.in.am=true”and "hive.compute.splits.in.am=false"

[LLBian]

Hello, all:
     As shown in the topic, I am so confused by this onfiguration parameters 
“hive.compute.splits.in.am”.
what is the difference between“hive.compute.splits.in.am=true”and 
"hive.compute.splits.in.am=false"?
which value is better? 

What's the difference between the application scenario？

Any reply are very appreciated.

--LLBian