My requirement is very simple.
I want to store metadata in document level and that could be of any json structure.
I want to check any option by which I can seperate it out from fulltext content.
Search should work on specifically only on metadata fields, fulltext content and on both fulltext and metadata.
Metadata search should give me hit count on how many times the search term appears in document's metadata, as well as the total number of documents for which the match appears.
It would be better, if I could aggregate and sort on any metadata field in future.
I was looking for _meta field stored in document level. However I am not sure if that is recommended for my use case and solves all my requirements.