I have ended up with a situation of duplicated entries in archive explorer for the majority of our archives. To cut a long story short, there were unexpected issues with a move archive process. This is a small site, so to remedy a problem with orphaned shortcuts, all archives were exported to PST using the option 'all items', and then back into the vault, to the same archive, in order to recreate mailbox shortcuts that had failed to be updated by the move archive process. The broken shortcuts were then cleaned up by shortcut processing. So from an Oulook view, it all looks ok and appears to operate fine.
Archive explorer shows duplicate entries, and I know with hindsight this is because the option to remove the items from the vault first wasn't checked. Quite why EV doesnt just check that the items are already there when performing a merge PST import I don't know.
Is there any way we can now cleanup the archives so the duplicate entries are removed? Perhaps a SQL script to check and remove?