On Wed, Sep 7, 2016 at 4:03 AM, Josh Berkus <j...@agliodbs.com> wrote: > On 08/29/2016 06:52 AM, Fujii Masao wrote: >> Also I like the following Simon's idea. >> >> https://www.postgresql.org/message-id/canp8+jlhfbvv_pw6grasnupw+bdk5dctu7gwpnap-+-zwvk...@mail.gmail.com >> ----------------------- >> * first k (n1, n2, n3) – does the same as k (n1, n2, n3) does now >> * any k (n1, n2, n3) – would release waiters as soon as we have the >> responses from k out of N standbys. “any k” would be faster, so is >> desirable for performance and resilience > > What are we going to do for backwards compatibility, here? > > So, here's the dilemma: > > If we want to keep backwards compatibility with 9.6, then: > > "k (n1, n2, n3)" == "first k (n1, n2, n3)" > > However, "first k" is not what most users will want, most of the time; > users of version 13, years from now, will be getting constantly confused > by "first k" behavior when they wanted quorum. So the sensible default > would be: > > "k (n1, n2, n3)" == "any k (n1, n2, n3)" >
+1. "k (n1, n2, n3)" == "first k (n1, n2, n3)" doesn't break backward compatibility but most users would think "k(n1, n2, n3)" as quorum after introduced quorum. I wish we can change the s_s_names syntax of 9.6 to "first k(n1, n2, n3)" style before 9.6 releasing if we got consensus. Regards, -- Masahiko Sawada NIPPON TELEGRAPH AND TELEPHONE CORPORATION NTT Open Source Software Center -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
