Photoshop Elements 2020 Backup Catalog.buc

Hi @rogerj23347315 ,

You don't seem to realize that you are perhaps the only PSE user who has ever been trying to use the 'catalog.buc' file directly with the purpose of  restoring a PSE backup, which means restoring both the catalog and the photo files to a (possibly new) location on your computer.

You are not supposed to use the catalog.buc directly, you are not required to know it even exists. You have to deal with an entity which is a 'backup folder' as a whole. The catalog folder might have been a special kind of archive, like a zip, in which you would not recognize any of the components.

In the same way, the 'catalog folder' of the organizer is not a single file like in Lightroom, it's a whole folder containing many components: several sqlite databases, mainly the 'catalog.pseXXdb' main database and the thumb.5.cache which keeps the thumbnails.

Since you have been examaning the contents of both kinds of folders, catalog or backup, let's go a little further to better understand how that works and find precise answers to your questions.

Since the PSE organizer definition of a 'catalog backup' is to save BOTH your catalog folder AND your photo files hierarchy in such a way that you can restore everything even in another drive or computer, it is rather obvious that the resulting catalog backup must contain everything of the catalog folder, every single photo file (including sidecar xmp files) and a description of the photofiles hierarchy to be able to restore everything in the same structure or a simplified one, and that on a new, different drive.

Including all the components of the catalog folder includes the main catalog.pseXXdb database and all other components including the thumbnail cache.

Including all the photo files is done by renaming all the media files with a name starting with 'B00' and a new order number in a single flat folder.

To be able to restore the original structure, a special field, backup.tly keeps the link between the new renamed copy and the description of the path and structure in the original library.

Without that backup.tly, it's impossible to recreate the file structure from the flat folder containing the renamed files. Any backup folder without a backup.tly can't be restored.

Knowing that, what can you do with a 'catalog.buc'? 

What if you are interested in a backup of the catalog folder only? That's what Lightroom offers and leaves the user to find an external backup system for the media files themselves. That's also what the current PSE2021 offers: an alternative way to backup ONLY the catalog folder.

It's no secret that you only have to make a copy of the whole catalog folder to get a catalog backup. You can copy or move the catalog folder anywhere else and its contents are kept. The links to the files themselves are kept, so long as the media files don't move externally. You get a total safety if the contents of the catalog folder are corrupt or unavailable. You lose everything is the photo files are no longer safe (= possibly backed up separately).

When you use a catalog.buc file, you are using a copy of the real catalog.pseXXdb files as described above.

I have stated long ago that if the only file you can save from a whole catalog folder is the main catalog.pseXXdb, you can use it in a new empty file as a minimal catalog folder;  that will recreate a number of very important items, including the thumbnail cache (see my previous answer). I had never considered that you could use the catalog.buc directly without renaming it back, but its contents are absolutely the same and it seems normal that it can be used as such.

What you have to consider is that if you are moving to a new computer, only the full backup and restore will be able to create a valid backup folder (with the backup.tly and the catalog.buc). If the backup is from an older version, no problem, after restoring the photo files the restore process will 'convert' the catalog format to the new current format.

Using only either:

- the catalog.buc

- a manual copy of the catalog.pseXXdb or of the whole catalog folder.

- the catalog structure only new feature in PSE2021

will protect you againt corruption of the catalog database only.

The thumbnail cache will be recreated (may take several hours)

Restoring from only the catalog.buc or a single copy of the catalog.pseXXdb will retore albums, stacks, version sets etc. bu not face recognition and other features like visual similarity.