I think my Lightroom catalog is fine but I did notice that the integrity check and optimization process took a really long time at one point. Seems to be back to normal now, and there were never any error messages.
Catalog has about 35,000 images in it and the backup is about 650 MB. A normal integrity check/backup/optimization routine takes about 3 minutes, tops. So when the integrity check by itself was taking 10 minutes, I was getting concerned.
I'm curious if there is a separate repair tool for the Lightroom catalog. Microsoft has this type of tool for Microsoft Outlook- called ScanPST it is designed to scan through and repair most problems with the Outlook database. It would be great if Adobe had a similar tool for the Lightroom database that did not require running Lightroom.
I can't believe the developers don't have an internal tool that they wrote for that purpose... trick would be getting them to release it to the general public. (If anyone knows where I can make such a suggestion where it might actually take flight, lemme know.)
I'm curious if there is a separate repair tool for the Lightroom catalog.
There is not. If catalog goes bad, your only recourse is a backup (I mean, other than ad-hoc repair, or giving to somebody at Adobe..), and if you're smart (er, I mean "concerned enough"), you'll save (xmp) metadata too, as you edit, to supplement a saved catalog backup, should the need arise. That's just my opinion - some people are comfortable relying solely on catalog backups, and don't bother with xmp.
Keep expectations low: most suggestions go unacknowledged for years..