What is this "catalog target folder" that you speak of? It would be one thing to have something watch a single (or a few folders) for new additions, but we can't be constantly scanning all of your drives for new files being added. It would perform poorly.
-Kirk
I know this is an old tread but I think this question is very important and it seems to come back regularly.
I have worked seven years until 2013 with a DAM-software called FotoWare (not misspelled english "Foto" is just norwegian and swedish for "Photo" :-).
Fotoware had an indexing engine they called Index Manager and it was constantly monitoring the filesystem changes for (updates, deletes and appendings).
Usually it took a secound or so for a change to appear i the different indexes and it was always changes done outside the Fotoware system itself.
We had an integration with old legacy SQL-databases that was maintaines with other applications.
Still it´s very fast.
It would not be possible with a non-automatic system like Photo Mechanic's in an Enterprise, depending on the user to maintain sync in the system.
That´s why there has to be an automatic monitoring of file system flags when changes occur in the folders indexed by an Enterprise DAM.
The XMP-catalogs worked pretty much as they do in Photo Mechanic where you point on a folder structures top folder when indexing a catalog.
It would be no problem really to replace Photo Mechanic's indexing service and vise versa with Fotoware's and reindex.
(Of course you have to build schemas and forms that fit the data in FotoWare in order to be able work with the data or forms that matches Fotowares data in Photo Mechanic. I guess that Photo Mechanic creates the schemas automatically in the background when we build the forms to make it a little more easy than in FotoWare for us.
It´s a little bit unfair to compare an enterprise DAM with a dedicated indexing server perhaps but you also could run Fotoware as a single user application too.
They had a Windows and Mac-application called Fotostation, that could run on an ordinary PC.
Even in that case the changes are monitored automatically.