On Wed, Nov 7, 2012 at 5:34 PM, Simon Riggs <si...@2ndquadrant.com> wrote: > I was unhappy with changing the behaviour of TRUNCATE, and still am. > So the proposal here is to have a specific modifier on TRUNCATE > command that makes it MVCC safe by throwing a serialization error. > That new behaviour should be requestable by adding the SERIALIZABLE > keyword. > i.e. TRUNCATE foo SERIALIZABLE; > This then allows a new style of TRUNCATE, yet without modiying > behaviour of earlier programs (ugh!).
Personally I think the behavior should be dictated by the *reader*. The one doing the truncation may not know about the consistency requirements of particular readers. Especially when you do the truncate via pg_restore or some other generic tool. And indeed different readers may have different consistency requirements. So I'd prefer if it were a GUC variable; readers that accept relaxed consistency can set truncate_conflict=off Granted, making this part of the TRUNCATE statement does give you table-level granularity. But if a reader can already handle serialization conflicts, it doesn't really matter which table they came from. But making TRUNCATE behave in a MVCC-safe way, like proposed by Hannu, would be much better. Regards, Marti -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
