load custom minor/major modes

[Thomas Ruschival]

I found a elisp source that puts emacs into SQL*Plus mode for oracle SQL.
I can compile it and load it but ho do I tell emacs to load it whenever a file
called *.sql is opened?
I also like to modify the the java mode, I can't edit the global elisp
file and recompile it so can I also modify menues on a user basis like i can
set my tab size etc.?

Thanks 
Thomas