If you're working with a replicated database, always compact it twice before you synchronize.
The first time you compact, Access marks objects that need to be deleted, but it doesn't actually remove them.
The flagged objects are removed the second time you compact the database. Although there's no harm in additional compacting, there's no added benefit.
This is particularly important to do when working with the Design Master. Each time you make design changes to the Design Master, a copy of the original object is kept in the database.
If you edit and save a Report or Form 10 times, your database actually has 9 older versions of the form in it. The same is true if you change the schema of a Table or Query If you synchronize before compacting, all of the versions are sequentially sent to the other replicas until everything is in synch, and you can't reclaim the space taken up by the older versions.
However, if you compact the database first, only the most recent form version is sent to the replica.