When using <SQL REPEATABLE READ isolation level> and <SQL SERIALIZABLE isolation level>, concurrent transactions may fail with a serialization failure, and then you might need to retry them. You server code or your ORM must always account for that.

A good way to explore when it happens is to use the example

Related questions:
* https://stackoverflow.com/questions/7705273/what-are-the-conditions-for-encountering-a-serialization-failure
* https://stackoverflow.com/questions/59351109/error-could-not-serialize-access-due-to-concurrent-update
* https://stackoverflow.com/questions/50797097/postgres-could-not-serialize-access-due-to-concurrent-update/51932824


Ciro Santilli @cirosantilli 37

 Incoming links: SQL REPEATABLE READ isolation level