> On 02 Oct 2017, at 08:31, Masahiko Sawada <sawada.m...@gmail.com> wrote: > > On Sat, Sep 30, 2017 at 12:42 AM, Robert Haas <robertmh...@gmail.com> wrote: >> On Wed, Sep 27, 2017 at 11:15 PM, Masahiko Sawada <sawada.m...@gmail.com> >> wrote: >>> I think that making a resolver process have connection caches to each >>> foreign server for a while can reduce the overhead of connection to >>> foreign servers. These connections will be invalidated by DDLs. Also, >>> most of the time we spend to commit a distributed transaction is the >>> interaction between the coordinator and foreign servers using >>> two-phase commit protocal. So I guess the time in signalling to a >>> resolver process would not be a big overhead. >> >> I agree. Also, in the future, we might try to allow connections to be >> shared across backends. I did some research on this a number of years >> ago and found that every operating system I investigated had some way >> of passing a file descriptor from one process to another -- so a >> shared connection cache might be possible. > > It sounds good idea. > >> Also, we might port the whole backend to use threads, and then this >> problem goes way. But I don't have time to write that patch this >> week. :-) >> >> It's possible that we might find that neither of the above approaches >> are practical and that the performance benefits of resolving the >> transaction from the original connection are large enough that we want >> to try to make it work anyhow. However, I think we can postpone that >> work to a future time. Any general solution to this problem at least >> needs to be ABLE to resolve transactions at a later time from a >> different session, so let's get that working first, and then see what >> else we want to do. > > I understood and agreed. I'll post the first version patch of new > design to next CF.
Closing this patch with Returned with feedback in this commitfest, looking forward to a new version in an upcoming commitfest. cheers ./daniel -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
