On Tue, Aug 9, 2016 at 1:02 AM, Robert Haas <robertmh...@gmail.com> wrote:
> On Mon, Aug 8, 2016 at 10:10 AM, Rahila Syed <rahilasye...@gmail.com> > wrote: > > Thank you for inputs everyone. > > > > The opinions on this thread can be classified into following > > 1. Commit > > 2. Rollback > > 3. Error > > 4. Warning > > > > As per opinion upthread, issuing implicit commit immediately after > switching > > autocommit to ON, can be unsafe if it was not desired. While I agree > that > > its difficult to judge users intention here, but if we were to base it on > > some assumption, the closest would be implicit COMMIT in my > opinion.There is > > higher likelihood of a user being happy with issuing a commit when > setting > > autocommit ON than a transaction being rolled back. Also there are quite > > some interfaces which provide this. > > > > As mentioned upthread, issuing a warning on switching back to autocommit > > will not be effective inside a script. It won't allow subsequent > commands to > > be committed as set autocommit to ON is not committed. Scripts will have > to > > be rerun with changes which will impact user friendliness. > > > > While I agree that issuing an ERROR and rolling back the transaction > ranks > > higher in safe behaviour, it is not as common (according to instances > stated > > upthread) as immediately committing any open transaction when switching > back > > to autocommit. > > I think I like the option of having psql issue an error. On the > server side, the transaction would still be open, but the user would > receive a psql error message and the autocommit setting would not be > changed. So the user could type COMMIT or ROLLBACK manually and then > retry changing the value of the setting. > This makes more sense as the user who is doing it would realise that the transaction has been left open. > Alternatively, I also think it would be sensible to issue an immediate > COMMIT when the autocommit setting is changed from off to on. That > was my first reaction. > Issuing commit would indicate that, open transactions will be committed which is not a good idea in my opinion. If the user is issuing AUTOCOMMIT = ON, then it means all the transactions initiated after issuing this must be committed, whereas it is committing the previously pending transactions as well. > Aborting the server-side transaction - with or without notice - > doesn't seem very reasonable. > Agreed. Traditionally, open transactions in the database must be left open until user issues a COMMIT or ROLLBACK. If the session is changed or killed, then, the transaction must be rolled back. Regards, Venkata B N Fujitsu Australia
