Write-back changes to metadata immediately

[Stefanjan]

Newbie to iMatch, I have read the help and searched the forum but still would appreciate clarification.

I have 16,274 files "Pending Metadata Write-Back". Is it safe to simply use the Command or short cut to write all pending metadata? Are there any issues?

I've previously used Lightroom, Bridge, ON1 to manage my files.

Currently in preferences "Write back changes to metadata immediately" Do iMatch users normally check this box?

In the help files "Reading and writing of metadata is mostly done fully automatically by IMatch." I was expecting iMatch to eventually write meta data to my CR2 XMP files. This does not seem to happen. The help is a bit ambiguous in this respect. Does this mean " mostly done fully automatically providing you check Write back changes to metadata  immediately
"

I don't need write-back to happen immediately, as a background process would be fine

[Mario]

Currently in preferences "Write back changes to metadata immediately" Do iMatch users normally check this box?

This is off by default, because immediately writing back metadata after every change you make, rating you set, keyword you add etc. can be a severe drag.

Storing a label / rating / keywords in the database for 50 files: 0.2 seconds.
Writing back 50 RAW files: 20 to 120 seconds, depending on the RAW format, the state of the existing metadata, disk speed etc.

IMatch by default postpones metadata write-backs until you need to write-back (e.g. because you want to process the files in another software which also does metadata).
I would not write-back 16K files in one go. This can cause severe stress on your system, and it is very likely that there will be some problem files among 16,000 files.
If you write back by-folder or maybe 1,000 files in a go (just select 1000 files in the "Pending Write-back collection and run Command > Write-back for selected files or click the pen for one of the selected files).
This gives you a good impression of how fast the write-back is and if 1,000 files take a 5 minutes or 20.
IMatch writes back multiple files in parallel of course.

If there are problems (e.g. broken files not detected during import, files with metadata issues preventing safe write- back) it is easier to see which files are affected.
The files with problems will be marked with a yellow triangle (there is a special topic in the "Do You Know?" app with tips for dealing with this.

You only need to enable immediate write-back when you work with multiple applications on the same files at the same time.
See Metadata Write-back for details, and mabe also Using Adobe Lightroom® and IMatch together.

[Stefanjan]

You only need to enable immediate write-back when you work with multiple applications on the same files at the same time.

Thanks Mario, that was very helpful. I have written all the Meta data back and am left after rescanning with only 20 files "Entire file is binary zeros" and 1 file "File is not writable"

All of them CR2 files

Is it worth trying to recover these files and how would I go about doing that?

If not possible to recover I will take a look at adjacent files and decide whether important and then take a look at my image backups.

I don't plan to work with Lightroom or other DAM, but I am interested in writing back xmp as I will be working in iMatch on both desktop and laptop.

I have turned on immediate write-back to see what the impact is. I have noticed so far that there is a delay before write-back. So although it says "immediately" it does come under the background processing tab. So does this mean iMatch waits till it's idling?

[Mario]

These are messages directly from ExifTool.
I suggest you check these files in your RAW processor / image editor.
From experience, ExifTool is rarely wrong.

[Stefanjan]

I suggest you check these files in your RAW processor / image editor.

Not able to read the files in a raw processor. They were actually in sequence in a single folder. Deleted them as I had plenty of good images in that folder from single day in 2017.