beautiful snej soup, yum

I gave a webcast last month for O’Reilly, and it’s up on YouTube now so you can watch it at your leisure. Here’s the abstract:

It can be very liberating to store your Couchbase app’s data as free-form dictionaries, free of the rigid schema of a relational database. But there’s a lot to be said for the syntactic comforts and conveniences of modeling your data as native Cocoa objects with predeclared @properties, the way CoreData does. Don’t fret – the CouchCocoa framework lets you do both, even in the same database. During this webcast I’ll show you how to acquire the glamor of an object model, while still letting your NoSQL freak-flag fly.

[I just posted this to the Couchbase Mobile community mailing list.]

TouchDB is a project I’ve been feverishly working on for a few weeks. It’s an investigation into the feasibility of a CouchDB-compatible database rewritten from the ground up for mobile apps. The comparison I like to make is that “if CouchDB is MySQL, then TouchDB is SQLite”. In fact, it uses SQLite as its underlying storage engine. You can read a longer justification for it on its wiki, as well as an FAQ and design document.

— It speaks CouchDB’s replication protocol. I’m pretty serious about that; I’m even documenting the protocol.
— It also understands a large subset of the REST API, enough so that it works with CouchCocoa. I’ve got a clone of Grocery Sync working as one of the demo apps in the project.
— The current implementation is for iOS. If the investigation pans out we’ll port it to Android, and possibly other platforms.

TouchDB is certainly not ready for prime-time yet, but here are some current statistics to whet your appetite:
• Code size of an ‘empty’ iOS app with nothing in it but TouchDB: ~150k.
• Time to initialize TouchDB and open a database, on iPad 2: ~100ms (cold) or ~60ms (warm).
• Size of source code: ~4000 lines of Objective-C (plus another ~2500 lines from some existing utility libraries.)

What’s left to do? Probably a lot — that infamous “second 90%”. Prominently:
• Attachments
• Reduce functions and grouping
• Filters for views and replication
• Performance tuning
See the issue tracker for more.

So, what does this mean for Couchbase Mobile? Honestly, we don’t know yet. It may be that TouchDB turns out to be so awesome that it replaces embedded-CouchDB entirely in Couchbase Mobile on iOS and Android. It may be that there are still scenarios where embedded-CouchDB works better and is worth the extra overhead for some developers, in which case we’ll still support it. This is not a product announcement; it’s a technical announcement of something that isn’t a product yet, because we like to do our development in the open. We’d love your feedback or even contributions.