title: What will be the affect of fielddata=true when querying a ~10M document index and more questions
body: <ol>
  <li><p>I have an index of ~10M docs. In each document I have a 'text' field where I put a string in and in the end I want aggregate all the terms inside this field. When trying to do that I only get the entire string.
  I heard only bad things about using fielddata=true. 
  For this amount of documents, is it really such a bad practice to use fielddata=true in terms of memory?</p></li>
  <li><p>Is there a difference (in terms of performance) between using an analyzer in the indexing pipeline (just set an analyzer on a specific field) to using an analyzer as a function (run analyzer on a string, get the results and put them in a document)?</p></li>
  <li><p>Synonyms - I have defined a list of synonyms, I believe I already know the answer but still I'll give it a try, Is it possible to simply update such list of synonyms and that's it? or it's a mandatory to re-index after updating the synonyms list?</p></li>
  </ol>