This might not be exactly what you want, but you could:

1.) do a full 1:1 copy of both the database and the filesystem (leave out the derivatives)
2.) in the new instance, use batch manager -> "Search" filter -> filter on tags here.

Unfortunately, a simple "NOT tag:foo" doesn't work for some reason, so a trick is "score:* OR score: NOT tag:foo"

From the help text:

Hint: score:* will give you all photos with at least one vote. score: will give you photos without votes.

"score:* OR score:" will give you all images, and adding "NOT tag:foo" works then. *shrug*

So, this will give you all images that do not have tag "foo".
3.) select the whole set and delete.
Done.

Doesn't solve the duplication issue, though. 2 instances are 2 instances. Any reason not to use the private album feature?

Last edited by teekay (2016-10-12 16:10:30)