Rebuilding ports database

A couple of ways to update the database used by the ports package (portupgrade, etc):

• pkgdb -Uu


• In /usr/ports, do make index

Of course, on my computer both generate a boatload of errors, and now I'm trying to figure out if they are important, and how to fix them if so. I know about pkgdb -F, but it asks me all kinds of questions I don't know the answer to.