Beyond Relational Databases "Old-style database systems solve old-style problems; we need new-style databases to solve new-style problems. While the need for conventional database management systems isn’t going away, many of today’s problems require a configurable database system. Even without a crystal ball, it seems clear that tomorrow’s systems will also require a significant degree of configurability. As programmers and engineers, we learn to select the right tool to do a job; selecting a database is no exception. We need to operate in a mode where we recognize that there are options in data management, and we should select the right tool to get the job done as efficiently, robustly, and simply as possible."
Interesting perspective (albeit with many extrapolations/projections with which I don't agree) from the CTO of Sleepycat.