Tag Manager: sense to unable not used tags?

[sinus]

Hi
When I open the Task manager and let show me all Tags (uncheck "show only groups and tags with data") I have quite a lot of groups and tags, what have no entries in my database.
Groups like

- Audible
- Audible cvrx
- Casio
- FLAC
- FLIR Moreinfo
- HTML Office
- Kodak DcMD
...

and so on. All this groups are checked, but I have no files in this groups (indicated by "

• ) and will  have quite sure no files in the future.
  
  Does it makes sense and a difference, if I uncheck such groups and/or tags?
  Does this makes IMatch maybe quicker, because it must not look for these groups or is it not important to uncheck these groups?
  
  And a last question, to see, if I understand the tag Manager correct:
  If I uncheck some groups, these groups and tags will not more imported into IMach.
  If I do then a diagnosis, the DB could be a bit smaller.
  
  But the info is still in the file or sidecar and I can see these tags alsways in the Exif-Tools.
  And if I want to import these infos, I can add the groups and tags and then make a rescan and these info is then also (again) in the database.
  
  Is this correct?
  
  Thanks for make me sure. 

[Mario]

You don't need to disable these groups. If ExifTool does not deliver the tags because your files don't contain this data there is no difference. No speed gain or anything.

You can disable a group (e.g. Nikon maker notes) to actively prevent IMatch from importing the data. If your files contain Nikon maker notes, IMatch will skip this data, which keeps the database smaller and improves performance a bit.

Tip: You can always see how much data for each tag was imported in the Tag Manager.

If I uncheck some groups, these groups and tags will not more imported into IMach.
If I do then a diagnosis, the DB could be a bit smaller.

But the info is still in the file or sidecar and I can see these tags alsways in the Exif-Tools.
And if I want to import these infos, I can add the groups and tags and then make a rescan and these info is then also (again) in the database.

Yes. This has been designed to be an 'interactive' process. If you find metadata is missing, you can enable the tags in the tag manager, rescan the files, and the data will be imported. Data previously imported for now disabled groups will be removed during a diagnosis run (the log file even tells you how much data has been removed).

The effect on the database size may be more or less visible. Some tags require only a few bytes, other tags require 20-40 KB of storage (per file!). Some applications (Adobe, mostly) store vast sets of proprietary XMP data, which not only adds dozens of KB of metadata to a file, but often hundred or more extra tags. And this can bring performance down quite a bit. Since most of this data is useless for humans, it's best to keep it out (which IMatch does by default).

The database diagnosis log file includes some statistics about how much data is stored for what.

[sinus]

Mario, thanks for this.
l think, I understand now fully the ideo of the task manager.