Why is that the same forum? How about separate forums? PHP is no more relevant to MySQL than MySQL is to PHP--or to be more clear, it's no more relevant for PHP to MySQL than Perl is to CGI. Many languages use MySQL and have nothing to do with PHP. I realize many people think that they go 'hand in hand', but it's no more 'hand in hand' than Perl and MySQL or C and MySQL or Python and MySQL. These forums should be separate. I mean, this isn't specific to MySQL questions related to PHP somehow, is it? :-)
Too many people already seem to think that the two must be used with each other and this only makes it worse and makes more people needlessly make database connections and causing unneeded overhead and DB usage. MySQL questions will surely still be fielded fine in a PHP forum, but it seems odd to have "PHP and MySQL" as the name of the forum, since one doesn't have anything to do with the other anymore than any other language and MySQL.
Even if PHP makes it easier to use with it, so do other languages such as Perl, etc. and it would seem odd to tack on "and MySQL" to each of those forums. This is like saying Perl/CGI as a forum title (Perl is used for many other things, and CGI can be used for any language, so that would be wrong). I ask you consider removing "and MySQL" from the PHP forum and having a separate area for "Databases" that can have database scheme/design questions and different types (among them being MySQL). :-)