Specify which fields are indexed in ElasticSearch

Question

I have a document with a number of fields that I never query on so I would like to turn indexing on those fields off to save resources. I believe I need to disable the _all

Answer 1

Following is an important doc page to understand the index settings in elastic search http://www.elasticsearch.org/guide/en/elasticsearch/guide/current/mapping-intro.html

For your problem, ideally you should set the "index" flag to no in the field properties.