# ORM upgrade changes query semantics: first 30 minutes checklist

Source: https://releasefailures.com/incidents/orm-upgrade-changes-query-semantics/
Content version: 1.0.0
Verified on: 2026-10-22
Licence: CC BY 4.0

Definition: An ORM or driver upgrade changes default query behaviour and returns different rows.
- [ ] FM-01 Stop the job or endpoint that runs the affected query, such as the bulk email send or the bulk delete.
- [ ] FM-02 Compare the SQL or filter generated now with the one generated before the upgrade to confirm the dropped condition.
- [ ] FM-03 Pin the ORM back to the previous version or set the changed default explicitly, whichever restores the missing condition faster.
- [ ] FM-04 Count the rows or documents the faulty query touched, using logs or a backup taken before the upgrade.
- [ ] FM-05 Restore deleted documents from the most recent backup if a bulk delete matched the whole collection.
- [ ] FM-06 Contact each customer whose data reached another customer and state which fields were exposed.