Vlk
3
Yes it’s only 900K. That’s right. That’s all we need to find it all?
How do we do it? We just do 
And if you’re asking why the virus DB of avast32 3.0 is about 2.3MB and the one of avast 4 has only 900K, it’s easy to answer – compression!
Since you use Pro, it may need slightly less to update the file definitions.
Actually, no. These things are identical in both Home and Pro versions.
Vlk