[JDEV] can't find resources for...

[Darshan]

There are a few things about jabber, in general, that i'm having trouble
finding/figuring out:

- if all the user files are stored in one directory, then what happens
when more than 35,000 people try to register?  (only ~32,000 files can
exist in one directory, right?!)
- where can i download the 'mod_mysql' module i've seen refered to in
some people's posts?  
- is there a web page that lists all the *.jabber.org sites?
- i installed the server but for some reason searching
(jabber:iq:search), among other things, doesn't seem to be enabled! 
(and the server mini-howto was not forthcoming.)

i've followed just about every link on the jabber.org site (including
all past jdev posts) and couldn't find anything on these problems.  can
someone point me in the right direction?

thanks,
darshan