How to clear bullet physics simulation cache?

I just started to learn Bullet physics simulator. I created scene “domino falling” with 1300 dominoes, run BGE with “animation recorder”, it creates 830 frames of animation. After saving this simple file it’s size became 370Mb :eek: and Blender while working with it used 1.5 gigs of RAM. How can I purge simulation’s cache to decrease filesize? Or maybe it’s not any cache at all, main target is to reduce huge filesize and to free more ram…

Thanks.