It answers the question nicely, thanks for the feedback.

From your experience with the platform, are there any safeguards in place that prevent plugins from breaking out of their place in memory and reeking havoc? Are the plugins allowed to modify the underlying data structure or is there a specific interface they use to access the data?

I think the ability to modify the functionality of the RDBMS could be very useful in some instances, however if the plugin is poorly crafted or maliciously crafted it could open up interesting new attack surfaces. Any thoughts from the security minded out there?