[mythtv] Database design documentation?

[stan]

Does documentation for the underlying database structures, and usage exist?
If so, where can I find it?

I'm trying to repair a backed that has been damaged by some combination of
connecting to new a version frontend, and updating.

Specifically, the system thinks all the programs that were recorded before
this pair of events, are at least an order of magnitude to long. IE a one
hour program is listed (using "I" in the player) as many hours long.

-- 
Unix is very simple, but it takes a genius to understand the simplicity.
(Dennis Ritchie)