Use cases for hstore vs json datatypes in postgresql
Taken from http://www.depesz.com/2013/03/30/waiting-for-9-3-add-new-json-processing-functions-and-parser-api/ per dezso's comment:


  Given current limitations for both datatypes, I would say that they
  should be used in different scenarios:
  
  if you want indexable searches, and you’re fine with “no-nesting”
  limitation: use hstore. if you need nested, complicated structures,
  and don’t care about indexing – use json. and if you need the best
  from both world – you’ll have to wait to see what, and when, the
  future will bring.