Using one mysql database or few. What's suits for me?

[Feaftrort]

I'm looking for guidance. Here is what I'm doing.I'm creating an advertising/publishing script using PHP and MySQL. At this time, the current program contains 41 million rows (7.5GB).I'm thinking about storing real-time statistics and other data (users, ads, places, daily/monthly stats) on two mysql databases. And then update data (from real-time db to the 2nd db which shows users their statistics) using a cron thrice a day.So, will this be an 'UP' or a 'DOWN' (Good or Bad)?Thanks,pnm123