Interesting idea. `couch_index_server:get_index` already does some similar things in https://github.com/apache/couchdb-couch-index/blob/1843-feature-bigcouch/src/couch_index_server.erl#L64-L97 but that does a `fabric:open_doc` for clustered databases, and `couch_db:open_doc` for local databases, rather than using the `ddoc_cache:open`. So probably the best approach is to update `couch_index_server:get_index ` to use `ddoc_cache:open` in both of those code paths, although I would like to get @davisp's feedback on that.