Previously I had 4.6.1 and discarding image history took maybe 5 seconds for 200 images. Now it takes around a full second for each image, meaning 200 photos takes over 3 minutes while everything else in darktable is frozen. Anybody else experiencing this same issue?
When you discard, you are also telling dt to process the image with the default/auto preser processing. A log from -d common might be helpful to understand the issue.
This is interesting. While I agree that regenerating the previews using the raw file understandably takes time, it seems the enhancement for bulk operations does not cover this case:
The user interface now gives feedback while processing bulk image operations such as rating, tagging, applying styles, and edit history management (and undoing those operations), rather than silently freezing until the operation completes. While the operation is in progress, darktable will now show either a busy cursor (such as a stopwatch or spinner) or a progress bar with option to cancel the remainder of the operation.
[…]
Improved the speed of bulk image operations by improving the speed of sidecar writes, and by moving sidecar updates for many operations into a background task, allowing the user to proceed before the writes complete.
(darktable 5.0.0 released | darktable)
Same here, discarding history on 100 images takes me minutes. I ran DT in debug mode and got an huge amount of database calls while doing it, I opened a bug with it.