On Sun, Aug 30, 2015 at 10:36:23PM +0300, Oleg Bartunov wrote: > Honestly, I still don't know which approach is better, we already played with > XL (ported to 9.4) and identified some very strong issues with inconsistency, > which scared us, especially taking into account how easy we found them. XC > people have fixed them, but I'm not sure if they were fundamental and if we > could construct more sophisticated tests and find more issues in XC/XL. We > also > a bit disappointed by Huawei position about CSN patch, we hoped to use for > our > XTM. FDW approach has been actively criticized by pg_shard people and that's > also made me a bit suspicious.
Yep, that has me concerned too. The pg_shard people will be on the September 1 call and are working on a Google document to explain their concerns about FDWs for sharding. > It looks like we are doomed to continue > several development forks, so we decided to work on very important common > project, XTM, which we hoped could be accepted by all parties and eventually > committed to 9.6. Now I see we were right, unfortunately. Yes, the ability to add independent parts that can eventually be used for sharding is a strong indication that doing this incrementally is a good approach. > Again, could we organize meeting somewhere in September ? US is not good for > us, but other places should be ok. I want to have an agreement at least on > XTM. We still are testing various approaches, though. We could present results > of our experiments and are open to discussion. It's not easy project, but it's > something we could do for 9.6. Good. XTM is a must-have for several use-cases, including sharding. > I'm very glad Bruce started this discussion in -hackers, since it's silly to > me > to participate in both threads :) Let's meet in September ! In summary, I think we need to start working on built-in sharding, and FDWs are the only way I can see to do it with minimal code changes, which I think might be a community requirement. It might not work, but right now, it is the only possible approach I can see. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + Everyone has their own god. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
