Using data from the outside database for correlation

Hello ArcSight community,

Does anybody know if ArcSight is capable to use information from the outside database for correlation process? Let's say we want to have a rule which compares the ongoing event stream with the data in some outside database. Is it possible? The thing is that this database contains a lot of enties (few millions) and it can not be imported to a single Active List. I would appreciate a lot if someone could share their experience encountering similar problem(s).

Regards,

Gintuatas