Throw out your relational db for all but the tough queries

Amazon Simple DB continues the trend that for many many use cases the relational model and SQL queries, even pure data consistency, are overkill. Don MacAskill on his SmugMug blog has this to say about Simple DB:

Like many of you, I’m sure, we’re using much of our RDBMS as a fairly simple data store and aren’t using many advanced RDBMS capabilities. All of those queries could just use SimpleDB and then we could devote our DB iron to just the rare complex queries. We’re not alone - tons of web apps are gonna love this.

I think I have to agree with him here. The relational model is powerful, but it is hard to learn, hard to do right, hard to scale, tends to sacrifice performance for consistency, and adds a lot of complexity to your application. And more and more people are discovering that in many cases, you just don't need it.