I am trying to understand and effectively use the index type available in elasticsearch. However, I am still not clear how _type meta field is different from any regular field of an index in terms of storage/implementation. I do understand avoiding_type_gotchas
For example, if I have 1 million records (say posts) and each post has a creation_date. How will things play out if one of my index types is creation_date itself (leading to ~ 1 million types)? I don't think it affects the way Lucene stores documents, does it? In what way my elasticsearch query performance be affected if I use creation_date as index type against a namesake type say 'post'?