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.