DNG: what about xmp-files

[sinus]

Hi folks
This question is not important and I must say, I have not a lot googled for this. Maybe someone has a tip, if not, I have to google 

I have mostly jpgs and nefs (raw) in my DB.

I work with xmp-files for the nefs.
So usually I have a nef, a xmp and a jpg.

Now I have, because special circumstances, some DNGs and will have still in the future always some dngs to put into my DB.

I want to create from these DNG jpgs, for this I use Photoshop (the raw-converter).
But I have seen, somehow I get no xmp-files, although I have set in Photoshop the preference for this, see attachement 1.

I see also, that IMatch does somehow read the editing - work of photoshop, so they are stored, I guess, in the DNG.

Questions:
- how do I set some prefs, that I get also some xmp-files?
- or, if this is not possible, or not necessary, is it ok, simply work without such sidecar-files, for DNGs?

In IMatch, I have choosed, to use proxies for the nefs. I guess, this I can leave also for the DNGs, like I have it? (Because I have seen, that the DNG would take the "real" (edited) image for preview.)

Sorry for these DNG-questions, but to be honest, I want not dive too deep into DNGs, because I have decided, some years ago, against DNG for me.

[Carlo Didier]

DNG is supposed to have all XMP metadata inside and not in a seperate file. That's the design. Adding xmp files to them will just create confusion and unexpected results.

For me, the integration of all metadata inside the DNGs is a big advantage as I only have to handle a single file.

It can be a disadvantage if your backup software only handles entire files, as it will largely increase the size of incremental backups.
My backup solution is block based, so if some metadata in a DNG file is changed, it only backs up ~2k of data, not the whole 20+MB file.

[Mario]

DNG should always use embedded XMP metadata, never sidecar files.

[sinus]

Hey Carlo and Mario

Thanks really a lot, both of you.

Your answer helps me, calm down my nerves and make me relaxed.