I took some free time to port Prickle, my stay out of your way time tracking tool, from CouchDB to MongoDB. I originally wrote it to use Pylons and Couchdb specifically because I felt like studying a couple of technologies I hadn’t tried before. I found CouchDB to be a bit unwieldy to code with, and it didn’t take long for it to get slow on my Prickle datasets. Rather than figure out how to optimize CouchDB, I decided to port it to MongoDB.
The port was relatively straightforward. I was able to use pretty much the same model layout (Prickle has a very simple data layer). I tightened it up a bit to use actual references between models instead of implicit foreign keys by ids.
I chose to use MongoEngine for the database layer. I started with pymongo, but decided that a more abstract object-document-manager would be more useful.
I found querying in MongoEngine to be much simpler than the map-reduce queries in CouchDB. It is very similar to the Django ORM with which I am very familiar. Document creation and mapping is also familiar. Overall, I think Prickle will be a lot easier to maintain and extend using MongoDB than it was with CouchDB.
Prickle v0.4 does not contain any new features over 0.3. It also contains one bugfix to the date validation, submitted by Shelby Munsch.