I was initially sceptical over the NOSQL approach, but I have since changed my mind. Let me be very clear SQL is not dead, and it's the right tool for many jobs

I was initially sceptical over the NOSQL approach, but I have since changed my mind. Let me be very clear SQL is not dead, and it's the right tool for many jobs. However, if you want a cheap, replicated, multi-master, write heavy system - there is no simple way to this. Oracle is too expensive, I've used mysql-clsuter and pgpool-II etc, but in my experience they tend to introduce more failure points than they remove (at least in projects requiring a short development cycle). NOSQL pushes a degree of the complexity of the data model back to the application (e.g. you end up building some of your own indexes), but the data model is often no more complex in the end (less normalised, and greater flexibility of columns). The reward for this is massively simpler scaling. Something like Cassandra is so much easier to replicate to a multi-master multi-site system than PostgreSQL or MySQL. If you're building any form of semi-mission critical site (where you don't want to rely on or be tied to a single hosting provider) and you need to be multi-site & replicated from an early point, then NOSQL philosophy has a lot going for it. That said - I strongly hope that the MySQL/Postgres camp will fight back with a simple replication strategy that just works rather than is an bolt-on/afterthought. I find it helps to think of NOSQL being about simplifying the datastore to make it easier to replicate. So far I think only Cassandra does a persistent multi-master solution properly, but others will catch up.