On Thu, 2009-07-23 at 17:06 +1000, Chris wrote: > Joshua Tolley wrote: > > On Thu, Jul 23, 2009 at 02:04:53AM -0400, Glenn Maynard wrote: > >> On Thu, Jul 23, 2009 at 1:31 AM, Richard Huxton<d...@archonet.com> wrote: > >>>> - Let me use SAVEPOINT outside of a transaction, > >>> You are never outside a transaction. All queries are executed within a > >>> transaction. > >> "Transaction block", then, if you insist. > >> > >>> I think this is the root of your problem - all queries are within a > >>> transaction so either: > >>> 1. You have a transaction that wraps a single statement. If you get an > >>> error > >>> then only that statement was affected. > >>> 2. You have an explicit BEGIN...COMMIT transaction which could use a > >>> savepoint. > >> Savepoints can only be used inside transaction blocks. My function > >> has no idea whether it's being called inside a transaction block. > >> > >> From inside a transaction block, my function would need to call > >> SAVEPOINT/RELEASE SAVEPOINT. > >> > >> If it's not in a transaction block, it needs to call BEGIN/COMMIT > >> instead. SAVEPOINT will fail with "SAVEPOINT can only be used in > >> transaction blocks". > > > > Have you tried this? I expect if you give it a shot, you'll find you don't > > actually have this problem. Really, everything is always in a transaction.
[snip] > You haven't explicitly started a transaction, therefore savepoints won't > work. True. However, he's talking about code within a PL/PgSQL function. To a PL/PgSQL function there is NO difference between: begin; select my_function(); commit; and a standalone: select my_function(); in both cases the statement executes in a transaction, and in both cases individual statements within the function are within the same transaction. That's why any function can EXCEPTION blocks, etc, which rely on savepoints. -- Craig Ringer -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql