However if you make your objects smaller you can fit more into the cameras viewing frustrum, unless you want to increase the frustrum with set camera distance.
that can be slower on smaller machines though.
the standard distance is around 5000 units for the camera frustrum
if you make a cube at a size of 1 then export this out of DB using the export mesh command, you will have a unit size to work with if you need it to be absolute in sizes between your 3d program and the size of one DB cube with a unit size of 1 on all faces.
provided your 3d package can read in the x file because if you convert it with another program in the midst of transfering to your main3d program sizes and results may vary.
If no-one gives your an answer to a question you have asked, consider:- Is your question clear.- Did you ask nicely.- Are you showing any effort to solve the problem yourself 