MythTV  master
Database Subsystem
No one is working on documenting the database subsystem.

There are a few classes that deal directly with the database: MythContext, MSqlDatabase, DBStorage, MDBManager, SimpleDBStorage.

And one function UpgradeTVDatabaseSchema() located in dbcheck.cpp.

MythTV's Configurable widgets also do save and restore their values from the database automagically when used in MythTV's window classes.