Re: Server times out when GROUP BY has more than one group

[Mike Mohr]

OK, first of all, true confession: I'm just a student stumbling around, continuously trying to make sense of things. My teaching assistant hasn't been of much help. That's how I ended up here.

"MySQL has no way of knowing that it's meant to aggregate." -- I gather that I'm using a nowhere approach.

What gets me is that I can do my own GROUP BY by specifying a specific department in a WHERE clause and repeat it for the other 8 departments and get the desired result all with a total duration time on the order of 10 to 20 sec. So what is MySQL is doing for the 180 sec?

Is there a way to make this work or should I conclude that I'm trying to do something that can't be done?

I'd very much appreciate it if someone could break this down into simple terms for me. Thank you.