How can I update a catalog on my laptop and then transfer the updates to master catalog on desktop?

Question

This is similar to Goeffbubbles question but I don't want to have the original files on both laptop and desktop
Here is the question:
I want to make a copy of a Lightroom 3 catalog to put on my laptop so while on the move I can be geo-tagging and keywording to 8000 photographs. I don't want to drag an external drive with me. I just want to be able to work on the catalog metadata and have all the updates/changes stored there (on the laptop)(in the catalog) and then transfer the catalog back to the desktop (to the primary archive) and have all the updates/changes pushed back into the DNG's or the XMP sidecar files alongside the CR2's. These changes would be only keywording and possibly writing GPS data into them….NOT image edits (that would probally require access to the original image files)
As a test, I tried "exporting as catalog", TWO images (with the source images "unavailable"). I flash-drived the resulting catalog to my laptop. I opened the catalog in LR3 and made changes to the metadata. I tried both "saving metadata to file" and "updating DNG previews" (which would be useless anyway since I could not write data back to the missing originals) and also tried doing nothing and just closing LR,  then pulling the flashdrive and plugging it into the DESKTOP.(knowing the changes are stored within the catalog itself only) I open the 2 picture catalog in LR and see the keyword updates. Hurrah!
I switch over to the master catalog. All I want to do is import the updated metadata (keywording, contrast, etc…) back into the master catalog and push the data into the original DNG or XMP. On import I select "replace: Metadata and develop settings only" (with or without "preserve old settings" checked) and click import. Voila! NOTHING HAPPENS and the updated keywords are NOT picked up.
Where did I go wrong? I know that the metadata updates were carried out because they showed up when I opened it separately in LR! For some reason they don't seem to making through the import process to the master catalog…
Sorry if I am being overly verbose....Any suggestions?

Answer 1

the part you're missing is that you have to be a little more destructive in your creation.
here are my steps:
In LR, put the files you want to work on in a subfolder of your Primary catalog
Export Folder As Catalog with previews, but without including the DNG's
At your new location/machine work on that catalog.
Here's the part that's no fun, (obviously have a backup of your catalog before you do this)
In your primary catalog REMOVE that folder from your catalog. (this will remove all references within your catalog, but leave the RAW files alone where they were)
You then FILE-->IMPORT FROM ANOTHER CATALOG, and import your subfolder export back into your Primary catalog.
It'll bring all of your changes and previews back into your Primary catalog but with unlinked RAW files.
Click on the question mark in the corner of the thumbnail that's telling you it doesn't know where the source files are and LOCATE the original file again in your file structure, with the FIND NEARBY MISSING PHOTOS box checked.
Overly complicated for what it is, but it gets the job done.
I found your post because it was suggested on the sidebar after I just made a feature request on the same topic.