Obviously it’ll depend on which update mode you’re using (e.g., when idle) and how much needs to be done.
I use the “screen-saver” mode, since I never use a screen saver, and while I don’t know how much of the 5 gigs or so on my drive is actually relevant, a VRDB update typically takes about 10-12 minutes.
And if by “interrupted” you mean you’re using the when-idle mode, and input activity causes it to pause, yes it’ll quite happily pick up where it left off once the keyboard and mouse are inactive again. It’ll go through this pause-resume cycle several times, if necessary.
