Merlin>My biggest sense of alarm with the proposed change is that it could
Merlin>leave applications in a state where the transaction is hanging there
How come?
The spec says commit ends the transaction.
Can you please clarify where the proposed change leaves a hanging transaction?
Just in case, the proposed change is as follows:
postgres=# begin;
BEGIN
postgres=# aslkdfasdf;
ERROR: syntax error at or near "aslkdfasdf"
LINE 1: aslkdfasdf;
^
postgres=# commit;
ROLLBACK <-- this should be replaced with "ERROR: can't commit the transaction because ..."
postgres=# commit;
WARNING: there is no transaction in progress <-- this should be as it is currently. Even if commit throws an error, the transaction should be terminated.
COMMIT
No-one on the thread suggests the transaction must hang forever.
Of course, commit must terminate the transaction one way or another.
The proposed change is to surface the exception if user tries to commit or prepare a transaction that can't be committed.
Note: the reason does not matter much. If deferred constraint fails on commit, then commit itself throws an error.
Making commit throw an error in case "current transaction is aborted" makes perfect sense.
Note: the same thing is with PREPARE TRANSACTION 'txname`.
Apparently it silently responses with ROLLBACK which is strange as well.