The idea from the idea of have different parts merged together has risen me the question if it is possible in that way not do do the full dump every time, but to use previous dumps (or more reasonable part of them) to create the new one.
I believe that's how the backups are done. A full backup is taken every day, or whatever, and inbetween backups the details of every change to the database is stored, and then if something goes wrong you can restore to the last backup and roll forward using the stored changes. I don't know if it's possible to use a similar system for dumps, but it might be worth considering.