Journey Emails
This comes up a lot — trouble joining the _Journey and _JourneyActivity data views. The issue is that the VersionID is a UniqueIdentifier data type behind the scenes. The workaround is to cast/convert it to a varchar(36):
Journey Jobs
I like to maintain a list of Journey _Job records beyond the 6 month lookback threshold for the data views. You can apply the same VersionID join trick on this one also: