How To Batch Deletes In MySQL Via orphanRemoval=true
Description: Batch deletes in MySQL via orphanRemoval=true.
Note: Spring deleteAllInBatch() and deleteInBatch() don't use batching. The first one simply triggers a delete from entity_name statement, while the second one triggers a delete from entity_name where id=? or id=? or id=? ... statement. Rely on delete() method.
Key points:
- in this example, we have a Tournament entity and each tournament can have several TennisPlayer (one-to-many)
- first, we dissociate all TennisPlayer from the corresponding Tournament
- second, we explicitly (manually) flush the persistent context (this will delete in batch all TennisPlayer thanks to orphanRemoval=true; if this is set to false, you will obtain a bunch of updates instead of deletes)
- third, we delete all Tournament via the delete() method (since we have dissaciated all TennisPlayer, the Tournament deletion will take advantage of batching as well)
Output example:
