[drbits]

@Jiaz:
Is the database using one of the common DB libraries that we might find tools for?

For instance, the full version of most DBMS can automatically copy the DB contents into another DB instance, leaving behind the dead space. For that matter, they can usually bebuild the indices (plural for index ).

@Tyop:
If the file is there, JDownloader will figure out not to re-download it.

If you are looking to save your completion history, select all of your completed packages, create a DLC, select the rest, create a DLC. Exit JDownloader and rename your configuration directory.

Restart JDownloader. Load the DLC for the completed packages, and disable them. Load the DLC for the rest of the link list and you are ready to go. You will lose the status of how much is downloaded within a package, but JDownloader will figure that out when it tries to download the links.