I had a weird experience with DTTG yesterday, which I verified today.
I have a database saved on an external volume which has a lot of files indexed (not imported), which reside on the same volume (mainly media files, video and images). It also has a lot of imported files, texts and PDFs. The database is synchronized to my mobile devices via a personal WebDAV server.
I was away from the Mac, browsing the database. When I saw a thumbnail for one of the indexed media files, I wanted to see how the app responded when trying to download the item. After a while, I was very surprised to see the item appear online on the iPhone, even though it has never been included in the database as an imported file. I thought this was pretty amazing.
To confirm that, I tried the same thing this morning, only this time I unmounted the volume which contains both the Mac database and the indexed media files. In that state, there was no way for me to access either the media files or the database (I check in DTPO, the database had disappeared from the Recent list).
To my even greater surprise, the iPhone app managed to download the media file for the indexed item and play it. I double-checked the database in DTPO, and the items I used to test this with appear with an arrow next to them (“indexed”) and when doing “Show in Finder” they indeed point to their path in the external volume.
How is that even possible?