[rules-users] More Design Questions

There is some commentary out there that says if the working memory gets too big than the performance of the rule engine will slow down. What is a good rule of thumb to know when to create a different working memories? Can the rule base be too big(have too many rules)? Is it reasonable design to break up the .drls by types of rules and have a separate rule base and working memory for each one? Cheers, Blair