#costo costco is a small UI for bulk editing CouchDB documents.

#install costco is a couchapp, you can push it to any db:

git clone http://github.com/harthur/costco.git
cd costco
couchapp push . http://hostname:5984/mydatabase

#usage costco takes a map function and executes it on all the docs in the database. The map function should return the new doc that you'd like to replace the old one, or null if it should be deleted. Returning undefined does nothing to that doc.

An example map function that increments a field in all the docs and deletes some docs based on another field:

function(doc) {
  if(doc.text.length > 200)
    return null;

  doc.count++;
  return doc;
}

More examples here. Right now this straight-up loads all the docs into memory, some batch loading might come in the future.