Greetings! On Fri, Dec 5, 2008 at 6:59 PM, Simon Riggs <[EMAIL PROTECTED]> wrote: > > On Fri, 2008-12-05 at 16:00 +0900, Fujii Masao wrote: > >> On Fri, Dec 5, 2008 at 12:09 PM, Fujii Masao <[EMAIL PROTECTED]> wrote: >> >> I was expecting you to have walreceiver and startup share an end of WAL >> >> address via shared memory, so that startup never tries to read past end. >> >> That way we would be able to begin reading a WAL file *before* it was >> >> filled. Waiting until a file fills means we still have to have >> >> archive_timeout set to ensure we switch regularly. >> > >> > You mean that not pg_standby but startup process waits for the next >> > WAL available? If so, I agree with you in the future. That is, I just think >> > that this is next TODO because there are many problems which we >> > should resolve carefully to achieve it. But, if it's essential for 8.4, I >> > will >> > tackle it. What is your opinion? I'd like to clear up the goal for 8.4. >> >> Umm.. on second thought, this feature (continuous recovery without >> pg_standby) seems to be essential for 8.4. So, I will try it. > > Sounds good. Perhaps you can share what changed your mind in those 4 > hours...
Yeah, it's my imagination about the real situation after 8.4 release, especially I considered about the future conjugal life of Synch Rep and Hot Standby ;) Waiting to redo until the file fills might lead to marital breakdown. > > Could we start with pictures and some descriptions first, so we know > we're on the right track? I foresee no coding issues. > > My understanding is that we start with a normal log shipping > architecture, then we switch into continuous recovery mode. So we do use > pg_standby at beginning, but then it gets turned off. Yes, I also understand so. Updated sequence pictures are on wiki as per usual. Please see P3, 4. http://wiki.postgresql.org/wiki/NTT%27s_Development_Projects#Detailed_Design > > Let's look at all of the corner cases also: > * standby keeps pace with primary (desired state) > * standby falls behind primary > * standby restarts to change shmmem settings > etc Yes, I will examine such cases! Regards, -- Fujii Masao 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