When I played around with smart rules, I accidentally saved this rule and had it active for a day or two while DT was running in the background:
I noticed this when files I created in some folders on my system vanished almost immediately. It was weird and it took me a while to figure out that the folders in which this happened were indexed in DT and it was DT moving those files them into its database 
Anyway, now that I figured it out, I wanted to check which files had been moved without me noticing but I’m not sure how i can search for all external files across databases. Is there a way? (sorry if this is trivial)
Another thing that I don’t quite understand is how exactly this rule is actually triggered. My thinking was that since the rule says “Search in Databases” it would never be triggered by some external files. So I figured that also external files that are indexed in DT are regarded as being “in the database”. Is that correct? It’s a bit confusing, because if they are already “in the Database”, you wouldn’t expect the action “Move to database” to do anything…
And then: the rule says that the actions should be performed “on demand”, “on startup” and “on import”. Why were they performed as soon as a file was created? I figured that since it can’t be triggered by “on demand” or “on startup”, it must be an import that is happening here, right? So I conclude that a file being indexed in an external folder is synonymous with it being “imported” into the database?