For us it depends. Each release goes through an evaluation and sanity check prior to go-live.

Continuous integration and test driven development mean that we have a high degree of confidence that things will work as rehearsed in the pre-live environment.

Some releases are code only, some are DB only. Some require both but the DB can go first shortly prior to the live deployment. Some require that the changes be made together.

Go-live doesn't particularly worry me, it is roll back that causes me to tuck my trousers in my socks so no-one can see I'm scared.