Efficient Zend_Acl/DB integration

Hey,

I'm new to the Zend framework, but am a long time PHP developer.  I've found
lots of tutorials that cover Zend_Acl in the sense of loading
roles/resources from the PHP code and even one that integrates to a DB, but
none of the tutorials that I've found cover cases with thousands of roles
and millions of resources.

Are there any good tricks or tutorials for handling "intelligent" or "lazy"
loading of a Zend_Acl tree for this sort of scalability?

Thanks,
Chris