Database SchemaG2
From GeeklogWiki
The database schema for GL2 is still in flux. The last thorough schema draft, created by Dwight Trumbower, includes partial schemas for several modules. You can see a visual representation of the database here and MySQL DDL here.
A more current, though less pretty, version of the schema can be found in the Geeklog 2 CVS. Note that the schema is still likely to go through several more permutations before reaching a final state.