CouchDB: Return Newest Documents of Type Based on Timestamp

Question

I have a system that accepts status updates from a variety of unique sources, and each status update creates a new document in the following structure:

{
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Answer 1

I suspect that it's slow only because you emit the entire document, which means a lot of data needs to be stored and moved around to compute your final values. Try emitting the timestamp instead:

function(doc) {
  if (doc.type == "status_update") {
    emit(doc.source_id, [doc._id,doc.timestamp]);
  }
}

function(keys, values, rereduce) {
  var winner = values[0];
  var i = values.length;
  while (i--) {
    var val = values[i];
    if (val[1] > winner[1]) winner = val;
  }
  return winner;
}

This should get you an [id,timestamp] pair for every key without being too slow or having to store too much data in the views.

Once you have a list of identifiers on the client, send a second request using the bulk GET API:

_all_docs?keys=[id1,id2,id3,...,idn]&include_docs=true 

This will grab all the documents in one request.