Database creation question

I have a question.  I am wondering if any one out there has ever made a
database which maybe have fields dividied by "#" or "///" --- something that
doesn't use mySQL, tables or columns?  OR another question is would it be
possible to install mySQL into my web site hosting package so I may use some
of my web site hosting disk space for mySQL purposes?  Is mySQL open source?

I want to create a series of discussion forums for my web site and I am
wanting to know if it is possible to use the web site hosting disk space
instead of the alloted mySQL disk space to hold the discussion messages.
Have any of you heard of the wwwboard on Matt's script archives?  It is
something like this I want to create.  If I use the disk space that HTML
files are typically stored in to store the data of the messages I will be
able to allot a good portion for messages and discussion to occur with; the
mySQL storage is more limited.

I am just starting to think about this now.

Ron