title: Elasticsearch document id type integer vs string : Is there any performace difference?
body: <p>I am using elasticsearch 2.3.1. Currently all the document ids are integer. But I have a situation where the document ids can be numeric valued or sometimes alpha-numeric string. So I need to make the field type 'string'. </p>
  
  <p>So, I need to know if there is any performance difference based on the type of Id. Please help....</p>