I find that I do a lot of thinking when i take public transport between places, so coming back from airport today my headspace was occupied with hybrid database (relational/columnar and object) and multi-tenancy archictectures - i..e how to support lots of different users with same infrastructure resources. So it was a nice suprise that i found Jed Fisher had recently pointed to a great article on this. (if you don't know Jed's scoop it site - its Visualizing Reality in All things 3D and CAD - covers more than just graphics and worth a daily read). Rescooping here so I can find it easily. Click on the image or title to discover a great introduction to multi-tenancy architectures and how to solve through data services.
Via Jed Fisher