My apologies - I was using Import when I should have been using the word Restore. I think I have also been getting confused with the difference between the Catalog - which i think is just a database file - which I have in the same directory structure as the photos and the Catalog when it is backed up using the Backup Catalog feature. From what you are saying this does not just backup the catalog but also backs up the photographs and maintains the file structure and all the tag information. So when you restore the catalog you have to do it to an empty area not one that is already populated with the photo files. Am I understanding this correctly?
So a restore from a full catalog backup should look exactly the same as it looked prior to the backup. Is this correct?
Once again sorry to be so dense but the previous time when my PC crashed I think I may have tried to restore the catalog by downloading all the photos and the catalog from OneDrive rather than restore from the PSE Backup.
My apologies - I was using Import when I should have been using the word Restore. I think I have also been getting confused with the difference between the Catalog - which i think is just a database file - which I have in the same directory structure as the photos and the Catalog when it is backed up using the Backup Catalog feature.
By @megagrumpyness
We are now on the right track! 'Import' or 'Restore', that's not only a matter of words, that's two existing functions of the organizer. Let's start with precisions about 'catalogs', 'catalog structure' and what I personnally call 'the library'.
- The 'catalog'.
Originally (up to PSE5) it was indeed a simple database file. From PSE6 on, it's now a distinct 'catalog folder' containing the primary database plus a number of other items managed by the catalog, like the thumbnail cache et the face recognition items.
- The Library: that's what I call the folder(s) tree(s) containing your media file.
The first confusion comes when Adobe speaks about 'catalog backups'.
For the organizer backups, what Adobe calls 'Catalog backup' is a special folder containing both the contents of the catalog folder, the library PLUS the necessary backup.tly file which keeps all the information about the folder structure of the library to reconstruct it in the same way from the restore destination you choose for the master folder.
So, that 'catalog backup' is a special package, not a working copy of your library. It can be moved or copied. It can be used only to 'restore' the library with the catalog and updated links (Not to be used as a second instance).
So, the 'backup folder' contains everything to restore. It's big, It's slow to backup, slow to restore, but fully flexible and adequate for non pros. You can choose where to restore (to migrate to a new computer for instance) and even restore on the original location if files or catalog have been corrupted in between.
The second confusion comes when things are changing. Most users also use external backup solutions, excellent for the library itself, fast and flexible, but inadequate for keeping the links in the catalog if the files are restored elsewhere. At the same time, Lightroom users are offered another solution skipping the backup of the library which the user has to manage on his own responsibility. The good news is that Lightroom offers a powerful and relatively simple reconnection tool to update the links in the database.
So, Adobe also starts to offer a 'catalog structure' backup solution, skipping the backup of the files of the library themselves. Imagine a simple copy of the 'catalog folder' without the thumbnail.cache which can be rebuilt automatically.
You can be prompted to do that backup at the end of your editing session. It's fast and protects you against dangers to the catalog itself. The 'reconnection' function is not there if you have to restore the library to a new drive from an external backup tool. So a good additional safety which does not completely replaces the classical Organizer 'catalog backup' including the library.