Can _type be doc_values?

I use term agg for compute topN of _type. Then I find that _type using fielddata memory, 500MB per node. I try to define "_type": { "doc_values": true } in template.json, even the POST return acknowledeged true, I didn't find such string in _template API result.

So, can _type field be doc_values?

You can currently, but from ES 2.0 you won't be able to -

But howto check the effect? I GET the new index mapping, but can't find anything abount _type.