According to the docs I've read, when I do a backup of a FB DB, every
record has to be "read" and old versions dealt with, so, a backup
inherently does a sweep. So if I back up twice a day, then I should
never have to do a sweep?

Is this true?

(Also: Thanks to Helen Borrie for her detailed explanation about the
CPU 50% problem/MS Access. She put a lot of effort into her answer
and we all really appreciate her taking the time)