[Phanx]

If your main saved variable is already a table, you can just use a sub-table in it instead of adding a second saved variable; eg. in Grid I do something like this:

Grid.db.profile = {
     -- bunch of settings here
     minimap = {},
}

LibDBIcon:Register("Grid", GRID_LDB_OBJECT, Grid.db.profile.minimap)

This is also an example of where the :Refresh method is useful -- when the user switches their profile, I need to call :Register with a reference to the "minimap" sub-table in the new profile table.