Cloudant/CouchDB Is it possible to create a view checking to see if there's any duplicates?

Question

I have a view

function(doc) {
    if (doc.type == "XXXXX") {
            emit(doc.name, 1);
    }
}

Is it possible to change it so that the view only emits that doc.name if already doesn't exist? I'm fully aware that you have the reduce function; however, it still slows done the initial build of the view.

Thanks in advance

Answer 1

Check out couchdb reduce grouping . I think if your view did this for emit:

emit(doc_name,1)

and your reduce function was _sum, you could query this map/reduce view with group=true

Answer 2

Fundamentally, the map function only has the context of the document that is passed into it. The only possible optimisation is an Erlang native view (or Cloudant Query - note that reduce is not currently exposed though).

Answer 3

I think the only way is to use reduce, then for niceness dbcopy:

"map": emit(doc.name, 1);

"reduce": return keys[0];

"dbcopy": "unique_names"

This way you have a new pre-computed database called "unique_names" of only unique items.

I don't think it's possible without reduce as your question requests.