On 09/02/2009, at 11:19 PM, Mister Donut wrote:
I would just, really really really, like to see an example that goes beyond schema-free. That handles replication. I think that would show where CouchDB shines, and where you'd fail with a RDBMS.
I presume you've seen http://wiki.apache.org/couchdb/ CouchDB_in_the_wild.
CouchDB is useful even where you wouldn't fail with an RDBMS. The data model, HTTP API, and map/reduce materialised views are features that makes some applications considerable easier to conceptualise, design, write, deploy and manage, and that's ignoring replication.
Considering replication, I'm about to deploy an application platform that uses replication to distribute read-only data *and* applications that use that data in a p2p mesh. I don't know how I would do that using an RDBMS - I guess I'd end up replicating CouchDB's mechanism in some form.
A putative extension to that gig is to make it into a p2p read/write collaborative content development platform. Once again, CouchDB replication to the rescue.
I have another contract about to start for a server app where all the data is maintained on the client's desktop, previewed with full functionality, and then replicated to an EC2 instance. This can be done with traditional databases, but it's trivial with CouchDB, which has allowed me to both outcompete on price and improve my development margin. That's one definition of success.
Furthermore, in each of these gigs, having the content in JSON is amazingly convenient. In some cases I need joins and dynamic queries, but I can do that using Couch's _external mechanism that allows alternative indexing.
In one case I've gone through three delivered versions, from Java/ Spring/Hibernate/Postgresql, to VisualWorks Smalltalk/GLORP/Postgresql to CouchDB/Merb/Ruby. IMO Ruby/Smalltalk are to Java as CouchDB is to an RDBMS. I never want to go back. Well, apart from going back to Smalltalk.
Antony Blakey ------------- CTO, Linkuistics Pty Ltd Ph: 0438 840 787 If a train station is a place where a train stops, what's a workstation?
