[otrs] Indexing and Database Questions

Hello; I'm newbie and I have some questions: 1) I think that OTRS index the words of incoming & outgoing mails. Does OTRS index the contents of attached files? Does OTRS support indexing of pdf attached files and other formats? 2) Each attached file, is it archived inside the database or outside the database? So, if it is archived inside the DB, how the DB will grow? If a customer sends to me a 500 MB exe file, my DB will grow 500 MB? 3) Is version 5 of mysql supported? Is it recommended? Thanks a lot.