Emerging software architectures and non-relational software

Fantastic article by Dion Hinchcliffe’s about emerging software architectures (PDF here).

The most interesting thing to me? Non-relational databases - which I know NOTHING about. I mean, I’ve played with trivial flat file databases before, and XML, but what else is there? Here’s a quote:

Non-relational databases.  Tony Bain over at Read/Write Web recently asked “Is The Relational Database Doomed?”  While it’s far too soon to declare the demise of the workhorse relational database that’s the bedrock of so many application stacks, there a large number of promising alternatives emerging. Why get rid of the traditional relational database?  Certain application designs can greatly benefit from the advantages of document or resource-centric storage approaches.  Performance in particular can be much higher with non-relational databases; there are often surprisingly low ceilings to the scale of relational databases, even with clustering and grid computing.  And then there is abstraction impedance, which not only can create a lot more overhead when programming but also hurts run-time performance by maintaining several different representations of the data at one time during a service request.  Promising non-relational solutions include CouchDB, which I’m starting to see in more and more products, as well as Amazon SimpleDB, Drizzle (from the MySql folks), Mongo, and Scalaris.  While many applications will continue to get along just fine with relational databases and object-relational mapping, this is the first time that mainstream database alternatives are readily available for those that are increasingly in need of them.