There's some great discussion here and understanding of the tradeoffs we considered when building the database-based blob storage (as opposed to storing files in the file system) and the 30-day soft-delete trash system.
I've posted a couple other places today about
- manually triggering the purge command to bypass the 30 day wait (ODK Central - How to delete a submission - #40 by ktuite)
- supporting the idea of clearing (a.k.a. deleting) submission attachments to free up some DB space, except in the case of edited submissions with multiple versions (Struggles in keeping the database to a reasonable size (AKA deleting submissions, deleting/clearing submissions attachments) - #4 by ktuite)
I also wanted to note @manghig's need for:
- Bulk deleting submissions via the Central UI. You're not blind, we have this for entities but not submissions, and the disconnect is unfortunate! We should definitely revisit this.
- More clarity in our docs about how sys admins can override the 30-day trash.
- More info about clearing submission attachments and how that relates to database storage.
Thanks for bringing up these pain points!