title: How to calculate number of executors and memory for each?
body: <p>Hi I have two nodes of each 16 GB RAM and 4 cores. 
  Can any one suggest me spark properties such as no of executors and executor memory to use it effectively?</p>
  
  <p>I am using spark sql query (Select * query with 2 joins) and also suggest me a way so that I want to bring down this querying process time to 1 seconds and my input data 10 GB as of now</p>