On Mon, Oct 24, 2011 at 11:33 AM, Heikki Linnakangas <heikki.linnakan...@enterprisedb.com> wrote: > On 24.10.2011 15:29, Fujii Masao wrote: >> >> In your patch, FPW is always WAL-logged at startup even when FPW has >> not been changed since last shutdown. I don't think that's required. >> I changed the recovery code so that it keeps track of last FPW indicated >> by WAL record. Then, at end of startup, if that FPW is equal to FPW >> specified in postgresql.conf (which means that FPW has not been changed >> since last shutdown or crash), WAL-logging of FPW is skipped. This change >> prevents unnecessary WAL-logging. Thought? > > One problem with this whole FPW-tracking is that pg_lesslog makes it fail. > I'm not sure what we need to do about that - maybe just add a warning to the > docs. But it leaves a bit bad feeling in my mouth. Usually we try to make > features work orthogonally, without dependencies to other settings. Now this > feature requires that full_page_writes is turned on in the master, and also > that you don't use pg_lesslog to compress the WAL segments or your base > backup might be corrupt. The procedure to take a backup from the standby > seems more complicated than taking it on the master - there are more steps > to follow.
Doing it on the master isn't as easy as I'd like it to be, either. But it's not really clear how to make it simpler. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
