Today’s Question: I just upgraded from Lightroom 5.7 to Lightroom CC. In the process, it appears that my catalog was copied, upgraded and renamed from Photos1 to Photos1-2, so now I have two catalogs. Is there any reason to save the Photos1 catalog or can I safely delete it?
Tim’s Quick Answer: Provided the new catalog is working properly, there is no reason to retain the older version of your catalog other than as a “worst case scenario” backup. So once you’re confident the new catalog is in good shape and you have backed up the new catalog, you can delete the old catalog.
More Detail: When you upgrade to a new “major” release of Lightroom, your existing catalog needs to be upgraded as well, so that the catalog reflects the new features and options available in the new version of Lightroom. As part of that process, your new version of Lightroom will create a new catalog that is essentially an upgrade to your existing catalog. In other words, your previous catalog will remain as it is, and a new catalog will be created that contains all of the information from your existing catalog.
While this is a good approach in terms of being cautious, it does mean that you may end up with several “extra” catalogs, by virtue of having catalogs from older versions of Lightroom. As far as I’m concerned, once you’re confident that your new catalog is in proper working order and you’ve backed up the new catalog, there is no real benefit to retaining old copies of catalogs from older versions of Lightroom.