"Applications using this level must be prepared to retry transactions due to serialization failures." ... "When an application receives this error message, it should abort the current transaction and retry the whole transaction from the beginning."
I note that the specific error codes this applies to are not documented, so lets discuss what the docs for that would look like. I had a conversation with Kevin Grittner about retry some years back and it seemed clear that the application should re-execute application logic from the beginning, rather than just slavishly re-execute the same SQL. But that is not documented either. Is *automatic* retry possible? In all cases? None? Or maybe Some? ISTM that we can't retry anything where a transaction has replied to a user and then the user issued a subsequent SQL statement, since we have no idea whether the subsequent SQL was influenced by the initial reply. But what about the case of a single statement transaction? Can we just re-execute then? I guess if it didn't run anything other than IMMUTABLE functions then it should be OK, assuming the inputs themselves were immutable, which we've no way for the user to declare. Could we allow a user-defined auto_retry parameter? We don't mention that a transaction might just repeatedly fail either. Anyway, know y'all would have some opinions on this. Happy to document whatever we agree. -- Simon Riggs http://www.EnterpriseDB.com/
