On Thu, Sep 19, 2013 at 7:32 PM, Fujii Masao <masao.fu...@gmail.com> wrote: > On Thu, Sep 19, 2013 at 7:07 PM, Sawada Masahiko <sawada.m...@gmail.com> > wrote: >> On Thu, Sep 19, 2013 at 12:25 PM, Fujii Masao <masao.fu...@gmail.com> wrote: >>> On Thu, Sep 19, 2013 at 11:48 AM, Sawada Masahiko <sawada.m...@gmail.com> >>> wrote: >>>> I attached the patch which I have modified. >>> >>> Thanks for updating the patch! >>> >>> Here are the review comments: >>> >> >> Thank you for reviewing! >> >>> I got the compiler warning: >>> >>> syncrep.c:112: warning: unused variable 'i' >>> >>> How does synchronous_transfer work with synchronous_commit? >> >> The currently patch synchronous_transfer doesn't work when >> synchronous_commit is set 'off' or 'local'. >> if user changes synchronous_commit value on transaction, checkpointer >> process can't see it. >> Due to that, even if synchronous_commit is changed to 'off' from 'on', >> synchronous_transfer doesn't work. >> I'm planning to modify the patch so that synchronous_transfer is not >> affected by synchronous_commit. > > Hmm... when synchronous_transfer is set to data_flush, > IMO the intuitive behaviors are > > (1) synchronous_commit = on > A data flush should wait for the corresponding WAL to be > flushed in the standby > > (2) synchronous_commit = remote_write > A data flush should wait for the corresponding WAL to be > written to OS in the standby. > > (3) synchronous_commit = local > (4) synchronous_commit = off > A data flush should wait for the corresponding WAL to be > written locally in the master. >
It is good idea. So synchronous_commit value need to be visible from other process. To share synchronous_commit with other process, I will try to put synchronous_commit value into shared buffer. Is there already the guc parameter which is shared with other process? I tried to find such parameter, but there was not it. Regards, ------- Sawada Masahiko -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers