On Tue, Apr 18, 2017 at 9:05 PM, Craig Ringer <cr...@2ndquadrant.com> wrote: > On 18 April 2017 at 18:55, Masahiko Sawada <sawada.m...@gmail.com> wrote: >> Hi, >> >> As doc of logical decoding said as a note[1], logical replication can >> support the synchronous replication with some restriction. But In >> addition to this, IIUC in logical replication decoded data is sent to >> subscribers only when the commit WAL record is decoded (calls >> ReorderBufferCommit) . > > Correct. > >> It means that the local SQL execution and >> applying the decoded data on subscriber side are always executed in a >> sequential order, and the response time can simply be doubled or even >> more (OTOH a good point is that decoded data of aborted transaction is >> never sent to subscriber). I think there will be a lot of peoples who >> want to use logical synchronous replication but this is a big >> restriction for such user. I think we should document it or deal with >> it. >> Thought? > > Definitely should be documented. I think it's covered under logical > decoding, but needs at least an xref.
Yes, I think so too. I'll send a patch for that this week, and maybe will propose a improvement patch for logical sync replication in the next release cycle. 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
