When upgrading from Jackrabbit 2 to Oak there are several scenarios that could benefit from the ability to upgrade repeatedly into one target repository.
E.g. a migration process might look as follows:
- upgrade a backup of a large repository a week before go-live
- run the upgrade again every night (commit-hooks only handle delta)
- run the upgrade one final time before go-live (commit-hooks only handle delta)
In this scenario each upgrade would require a full traversal of the source repository. However, if done right, only the delta needs to be written and the commit-hooks also only need to process the delta.