On Fri, Jun 19, 2020 at 6:33 PM Bruce Momjian <br...@momjian.us> wrote: > > On Fri, Jun 19, 2020 at 05:03:20PM +0800, movead...@highgo.ca wrote: > > > > >> would like to know if the patch related to CSN based snapshot [2] is a > > >> precursor for this, if not, then is it any way related to this patch > > >> because I see the latest reply on that thread [2] which says it is an > > >> infrastructure of sharding feature but I don't understand completely > > >> whether these patches are related? > > >I need some time to study this patch.. At first sight it is different. > > > > This patch[2] is almost base on [3], because I think [1] is talking about > > 2PC > > and FDW, so this patch focus on CSN only and I detach the global snapshot > > part and FDW part from the [1] patch. > > > > I notice CSN will not survival after a restart in [1] patch, I think it may > > not > > the > > right way, may be it is what in last mail "Needs guarantees of monotonically > > increasing of the CSN in the case of an instance restart/crash etc" so I > > try to > > add wal support for CSN on this patch. > > > > That's why this thread exist. > > I was certainly missing how these items fit together. Sharding needs > parallel FDWs, atomic commits, and atomic snapshots. To get atomic > snapshots, we need CSN. This new sharding wiki pages has more details: > > https://wiki.postgresql.org/wiki/WIP_PostgreSQL_Sharding >
Thanks for maintaining this page. It is quite helpful! -- With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com
