We are using OOB Archive/Purge wizard to create a zip file and purge the data. After the purge agent was run, we are unable to find the cases (either in UI or using the backend query from work table) as expected.
However we see that the DB space is not getting released. All the linked SYS_LOB specific tables (where the blob is stored) size remains as-is (no change in the size after purging). Kindly let us know if we are missing any other step.
I believe the Archive/Purge OOTB mechanism is only working on few tables. Only purging from the corresponding following tables:
This is also mentioned on the HELP file. You shouldn't be expecting any other tables to be purged. Also if your application is storing Data information associated with the cases on custom tables, those instances will remains untouched.