Hi,
On Fri, 12 Feb 2010 22:21:23 +0900, Koichi Suzuki <koichi.szk@gmail.com>
wrote:
> 2010/2/12 Fujii Masao <masao.fujii@gmail.com>:
>> Umm.. do you think that the "Export snapshots to other sessions"
feature
>> is
>> completely independent of the snapshot management for the parallel
>> pg_dump?
>> If not, we should make the patch more extensible for the feature we
want?
I think a common, more general implementation is possible, but certainly
requires more work than a plain parallel pg_dump solution.
> I don't think so. But in the cluster, from my experience of PG-2, it
> is essential to manage snapshot consistent among all the node involved
> and we should be very careful to make other local tasks, for example,
> autovacuum and analyze, not disturb other transactions because they
> can become global long transactions very easily.
Well, I fear that's heavily dependent on the clustering solution. So I
think the first step will be to have a general purpose snapshot exporting /
cloning feature for a single node (i.e. usable for parallel querying).
Extending that to allow for distributed parallel querying is the next step.
Regards
Markus Wanner