These things aren't necessarily considered Computer Science per se. Database systems generally are, which would include some projects on database design and optimization, but those things could be elective and not required for a major. A graduate's understanding of concurrency might be largely theoretical - I'd expect them to at least heard of mutexes, semaphores, etc., but how much they have used these tools in realistic programs and not just toys, not just to solve the Dining Philosophers' problem, probably varies hugely. As network programming was in its infancy when I got my undergraduate degree I can't really speak to it, but I suspect a similar split between academic topics and practical programming is at play.