.json files should not be appearing.

Just to add to what Glenn and Michel have already said, .json file are only used by face recognition.  So, if you turn face recognition off in Edit>Preferences>Media Analysis, no new .json files will be created.  However, any that were created before turning of the FR will remain in the Face Analysis/JSON folder of the catalog.  You can delete these if you are not using People tags for face recognition.  Deleting the files will also have no effect if you are using keyword tags for tagging people in your catalog. 

And just to give you an idea of the small size of the files, my catalog has 131,000 .json files which take up about 300 MB of storage. However, as Michel says, because they are many and small, they create an exponentially longer time to backup or move a catalog folder. 

I am using PSE15.

I have just created a new backup and I see .json files are still showing. I had already ensured that facial recognition was unticked and I had also performed the reset, so can anyone suggest why this is happening?

 

Also could you tell me what the following files are in the backup just to help me understand the process?

B0000000.cache

.xmp

Backup.tly

catalog.buc

By @sydhsydh

You should compare the contents of the [catalog folder] and a [backup folder].

The catatalog folder location is indicated in the menu Help >> system Information of the organizer.

The backup folder is in the location you have yourself specified for the 'backup' command of the organizer.
A full backup from the organizer implies saving all your media files and all the components of your catalog in a single folder.

All the media files are renamed and copied directly in the backup folder directly without the indication of the path structure tree. They are renamed starting with the letters "BO.....".

The "catalog.tly" file, as stated by Glenn, stores the full path of each renamed file.

Among the various components of the backup folder, you find:

- the B0000000.cache, a renamed copy of the thumb5.cache which is the cache storing all your thumbnails (it's an sqlite database storing the small thumbnails in a binary way your can't display yourself).

- the "catalog.buc" which is a renamed copy of the main catalog database, the "catalog.pse20db" files (for version 20).

I don't use face recognition, so I have no use for:

- json files

- xml files

If I disable face recognition, those files are no longer created, but the existing ones will stay. They don't take much space as they are extremely small, but with a big library, they require a long time to be copied/backed up. You can delete them manually from the explorer, but I recommend to work on a catalog folder copy or backup in case you run into catalog corruption problems.

xmp files are different from xml files, even if they are also very small text files. As stated by Glenn, they are 'sidecar' files storing the edits made to raw files.

XMP is generated when you edit a file in Adobe Raw- often refered to as ACR here.

Backup.tly contain a  cross reference between the real and full path original media file, and the renamed versions in the backup.

Catalog.buc is the contents of the catalogue. 

ABOUT  THE JSON FILES:  They are there because you have people stacks in oreganizer-- does not matter if you have all the faical rec. stuff deleselcted.  You delete the json files, you delete the people stacks.

All of these of basically system files you shouldn't be worry about, or be concerned with, especially if you are concerned about them taking up space.