If you were modifying the mysql code and providing a different version
fine. But in most cases you are simply using the database program not
modifying its source code. Your data structures and code that interacts
with the database should be unencumbered. Kind of like saying that
since you compiled your program using gcc that it now has to be
published as source code. I don't think that was the intention of the
GPL. And is not the way most people have interpreted it.
Most MySQL apps will be linked against the MySQL libraries. The developers have made a conscious decision to license the software under the GPL rather than the LGPL (which would allow 'unencumbered' distribution in the manner you described), so that's clearly *their* intention. And it's the way the GPL is intended to work. The GNU readline library is licensed in the same way. If you use it, you must GPL your code. If you don't want to do that, don't use it.
Paul.