FF 79 beta2 (latest beta): (I'm using win7 x86) FF 79 have new storage-sync-v2.sqlite, storage-sync-v2.sqlite-shm, storage-sync-v2.sqlite-wal files in profile folder. When I exit Firefox, storage-sync-v2.sqlite-shm, storage-sync-v2.sqlite-wal files are kept and not deleted unlike cookies.sqlite-wal, cookies.sqlite-shm, favicons.sqlite-shm, favicons.sqlite-wal. By the way, CCleaner > Custom Clean > Applications > Firefox > "Internet Cache" option deletes all *.sqlite-shm, *.sqlit