I looking for web stats software for windows which can grab apache log at specified time and create statistics. It also must have DB backend , so it must store cumulative data for already created reports in its own database. Is there anything like this in the market ?
It stores cumulative data in a database, it's just not user-queryable as far as I know (though it might use BerkeleyDB or something similar). In any case, no, it can't generate dynamic reports.
I think there are a couple for-pay solutions out there, but I'm broke and AWStats/Webalizer serve me just fine, so I don't know what they are. I did once have an entirely db-driven (ie. no log parsing - a php include) system, but it was poorly coded and didn't have the sort of reporting you desire anyway.