Autor: Mike Wiebeld Data: A: exim-users Assumpte: Re: [exim] The Future of Email is SQL
> > Yep - that is true. Of course I'm assuming that the backend would be a
> really good database. Or - perhaps the headers could be in a database
> and the messages stored in files in a way that the database could be
> rebuilt. I am just throwing these ideas out there to inspire thought so
> that maybe a year or so from now people might be using this idea.
That is how GroupWise handles it. Except it also excrypts everything so that
the files themselves cannot be read.
The first 4K of the message is stored in one of 24 databases, shared between
everyone. The rest of the message is stored as a binary large object
("BLOB") in a different directory. The users each have a database that is
little more than pointers to the primary database.
Exchange is similar.
It doesn't matter how "good" your database is. What matters is how good your
email administrator is. This model depends almost totally on his ability to
make regular backups of those databases and BLOBs. Then it depends upon the
tools to extract old messages from those backups and insert them into the
running ones. Compared to that, flat files or directories are the height of
easy.
And that doesn't even begin to address the problem of one user's pointers
getting corrupted and pointing to another user's messages. That's easy to
prevent and fix with files. It's a real problem with databases.