On Mon, Jan 09, 2006 at 15:22:09 -0500, Jaime Casanova <systemguards@xxxxxxxxx> wrote: > On 1/9/06, Chris Hoover <revoohc@xxxxxxxxx> wrote: > > > > Just to make sure I correctly understood what I read, once pg_dump issues > > the : > > BEGIN > > SET TRANSACTION ISOLATION LEVEL SERIALIZABLE > > > > The backup will only see transactions that were commited before the > > isolation level was set Is this correct? Any transactions that are commited > > while the backup is running are not seen by pg_dump. > > > > Correct? > > > > Thanks, > > > > Chris > > > > correct I don't think that is precisely correct. I believe that the snapshot isn't set until the first query is made within the transaction. In practice this won't be too much of a difference for pg_dump. But if you were entering the commands interactively and there was a long delay between the SET command and the first query, the difference might be significant. I found a comment on this at: http://64.233.167.104/search?q=cache:1QgAKZwFxK8J:www.sai.msu.su/~megera/postgres/gist/papers/concurrency/concurrency.pdf+postgres+snapshot+set+serializable&hl=en
