My question, is it possible that Aperture keeps all the thumbnails in the library when deleting the masters??
Wow, that is an impressive reduction in library size. I checked this with several test libraries in Aperture 3.4.1. Deleting images and emptying the Aperture trash resulted immediately in removing the thumbnails from the Aperture library. So what you observed is not the normal behaviour. At some point your library must have been corrupted, so that the thumbnails could not be removed, or Aperture crashed, before removing the thumbnails. The solution you found is somewhat drastic, but certainly effective Probably would importing your current library into a new library also cleared the orphaned thumbs and previews.
Thanks for this post.
I follows your steps and reduced my library from 69 GB to 24 GB. I am surprised that a product from Apple is so faulty when it comes to professional performance. Aperture does NOT delete thumbnails and previews when one deletes original images. And hence the library gets bloated.
Other than reclaiming space, I do not notice any improvement in performance or speed howsoever.
I also feel that Aperture is probably a faulty product by Apple and hence is being discontinued. I am a pro photographer and solely rely on Aperture for storage and editing. Everytime I run it (on my fairly high end MBP and iMac), the whole system gets bogged down, working on it is almost like trying to pull a ship with a bike).