Odd, because I literally do not know a single practising DBA that doesn’t have some form of on-call requirement as part of their job …
Anyway, in my experience, across all forms of administrative IT work be it systems, networks or what-have-you it is a common requirement to have to work at weekends or in the wee hours of the night as this is generally the only time certain maintenance tasks can be performed (patching, upgrading, moving, rebooting, config changes etc.). But overall hours worked in a week are usually normal enough, whereas some people working in development can be forced to work incredibly long hours. Varies from place to place but I don’t know any developers who regularly work < 40 hours a week.
I find working in IT very fulfilling but I’m not sure if it’s a good career to get into if you fancy regular office hours and all your weekends free.
But maybe other people working in the field have a different experience?