We're running 5.x something (don't care to look at the moment) we are fairly knowledable on tuning/tweaking. We use MySQL databases for some fairly RW intensive systems so having the db tuned to near perfection is critical.
I'm not the db guru by any measure, but I have guys working for me that are pretty wiz-bang.
The thing is, we did all of our tune/tweak processes BEFORE enabling Zlib compression, nothing worked or at least made any noticable difference. But turning on that compression was like flipping on a light switch, instantly the sluggish forum issue was behind us and has been since May 07.
