Where is the VRDB stored?
C:\Program Files\Alwil Software\Avast4\Data\Integ file\avast.int file
Which files are kept and what info?
Just the necessary
information of executable (.exe, .com, etc.) files, not the entire files.
I'm concerned about space.
I won't do so... I can't imagine some Mb are that bad for you...
I disabled VRDB but do not see how to enable it again?
If you disable, you won't be able to 'repair' infected files. You can enable VRDB by the 'a' blue icon on system tray: right click > VRDB > ...