database schema, user interface

Much as I like to rag on SQL databases, they are indispensible in dynamic web applications (recall how web 2.0 we are here at Astrometry.net), I am happy to report that Lang and I spent most of the day discussing the database schema for the web version of our automated calibration. The challenge is to stay close to what's known in the bidness as normal form. I think we came up with a schema that is useful, robust, and hard to corrupt. We shall see. Late in the day we worked on some user interface issues.