Using reduce with a composite key in couchdb view returns no result on GET - couchdb

Question

I have a couchdb view with the following map function:
function(doc) {
if (doc.date_of_operation) {
date_triple = doc.date_of_operation.split("/");
d = new Date(date_triple[2], date_triple[1]-1, date_triple[0], 0, 0, 0, 0)
emit([d, doc.name], 1);
}
}
When I issue a GET request for this, I get the whole view's data (2.8MB):
$ curl -X GET http://somehost:5984/ops-db/_design/ops-views/_view/counts
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 2751k 0 2751k 0 0 67456 0 --:--:-- 0:00:41 --:--:-- 739k
However, when I add a reduce function:
function (key, values, rereduce) {
return sum(values);
}
I no longer get any data when using curl:
$ curl -X GET http://somehost:5984/ops-db/_design/ops-views/_view/counts
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 42 0 42 0 0 7069 0 --:--:-- --:--:-- --:--:-- 8400
The result looks like this:
{"rows":[
{"key":null,"value":27065}
]}
This view & map & reduce functions were added using the Futon interface and when the Reduce checkbox is checked there, I do get one row for every 'date, name' pairs with values accumulated for that pair. What changes when queried through a GET?

Answer 1

When you calling the view through curl you can try passing in the necessary parameters for triggering the reduce and grouping
e.g.
Explicitly tell CouchDB to run the reduce function
$ curl -X GET http://somehost:5984/ops-db/_design/ops-views/_view/counts?reduce=true
Or the group and group_level params
You can read more on the available options Here (under Querying Options section)

Answer 2

The reduce should look like this
_sum
So a simple "view" would look like this:
{
"_id": "_design/foo",
"_rev": "2-6145338c3e47cf0f311367a29787757c",
"language": "javascript",
"views": {
"test1": {
"map": "function(doc) {\n emit(null, 1);\n}",
"reduce": "_sum"
}
}
}