Re: SET autocommit begins transaction?

On Wed, 18 Sep 2002, Bruce Momjian wrote:

> Sean Chittenden wrote:
> > > But it seems so illogical that SET doesn't start a transaction, but
> > > if it is in a transaction, it is rolled back, and this doesn't help
> > > our statement_timeout example except to require that they do BEGIN
> > > to start the transaction even when autocommit is off.
> >
> > Really?  To me that makes perfect sense.  Logic:
> >
> > *) Only BEGIN starts a transaction
>
> I think the above item is the issue.  Everything is clear with
> autocommit on.  With autocommit off, COMMIT/ROLLBACK starts a
> transaction, not BEGIN.  BEGIN _can_ start a transaction, but it isn't
> required:

AFAICT, according to spec, commit/rollback does not start a transaction,
the transcation is started with the first transaction initiating statement
when there isn't a current transaction.  And, most of the SQL92 commands
that start with SET fall into the category of commands that do not
initiate transactions.