Retiring a past session
Freeing space at the end of a semester without losing results.
Most of the disk is taken up by the detail of past sittings: what every student clicked on every question. Results and scores are tiny by comparison.
Retiring a finished session moves that detail out of the database and onto a file, then frees the space. It happens in two steps, and you can stop after the first.
Settings → Academic sessions → Retire, on any session that is not the current one.
Step 1: Archive
Writes every answer sheet and marked answer of that session to one file on the server, and checks it can be read back. Nothing is deleted, so this frees no space by itself. It is the copy that makes the second step safe.
Archiving is safe at any time after a session's exams are over.
Step 2: Purge
Checks the archive file is exactly what was written, then deletes the detail it holds.
What is kept: every student's score, every attempt, the papers, the questions, the course totals. Results pages and exports for that session keep working exactly as before.
What goes: the per-question detail — which option each student chose, the text of their essays — and with it most of the disk space.
What changes: a student's answer sheet can no longer be opened for that session. Instead of a blank page, openCBT says the detail was purged and lives in the archive file. If a dispute from that session is still possible, do not purge yet.
When openCBT refuses
The dialog lists the reason. All of them protect you:
- "This is the current session" — make another one current first.
- "N papers are still being sat" or "still being finalised" — wait.
- "N essay answers still need a mark" — purging would delete unmarked work.
- "N papers are being marked on the cloud" — bring their marks down first, or the marks would come back to rows that no longer exist.
- "The archive file is missing" or "is not the one that was written" — archive it again before purging.
- "Already purged" — nothing left to do.
Looking after the archive file
It stays on the server, and it is included in every backup taken afterwards. That is the copy to guard: once a session is purged, the archive is the only place that detail exists.
If you need to read one years later, it is a plain text file (one line per record, compressed) — your supplier can open it with ordinary tools, no need for openCBT itself.
A sensible rhythm
Archive a session once its marks are final. Purge it a semester later, when nobody is going to dispute a result from it. Keep the backups.