From 5.5 and above, Zoom offers the administrators the ability to shrink all the revision history of a file on the server. This feature is called flattening. This operation simply retains the asset in its latest content / name / location but removes all the past activity on that asset. Flattening can be invoked from the Asset Browser as well as from the command line client. Only users in the superadmin role are eligible to flatten assets.
The Mechanics of Flatten
Flattening operation leaves the asset of the same name, in the same parent folder, having the same data as its most recent revision. Only the revision history is erased. All other details like the metadata, keywords, links, layers etc. are preserved.
There is no discernible difference in any actions that are performed on the asset after flattening. It is as good as any other asset on the repository. Checkout, move, rename, metadata edit, smart-copy, preview etc., will all work as before. You can even flatten it again (and again, and again..).
Because flattening assigns a new asset ID, certain existing associations will not be preserved. A checked out file, if it is flattened on the server, will simply be deleted from the working copy on subsequent update operation. The flattened asset must be checked out anew. Similarly, an asset mapped to workflows, lightboxes or collections when flattened will no longer be available.
Flatten will remove association of that asset in workflows, lightboxes, collections and existing working copies. Such associations will have to be created again.
Internal Details of Flattening
If you are interested in looking up the flatten history of various assets, you can inspect the Zoom Flatten Tracker database from inside the web-based admin portal.
On command line ZM FLATTEN is laid out as shown here:
In the asset browser, flatten can be invoked from the right-click context menu, action menu and from Cart. as shown in the screenshot here:
After successful flattening of an asset, all the existing revisions will be removed and new asset ID is displayed with latest revision of that file.