[squid-users] Large Files

I'd appreciate some enlightenment as to how Squid handles large files
WRT memory and disk.

In particular;
   - squid.conf says that memory is used for "in-transit objects."
What exactly is kept in memory for in-transit objects; just metadata,
or the whole thing?
   - if something is in memory cache, does it get copied when it is
requested (because it is in-transit)?
   - How does sendfile support in 2.6 affect this?
   - Does anyone have any experiences they'd care to relate regarding
memory-caching very large objects?

Thanks!

--
Mark Nottingham
mnot@yahoo-inc.com