Fujii Masao wrote: > On Fri, Jun 26, 2009 at 7:14 AM, Heikki > Linnakangas<heikki.linnakan...@enterprisedb.com> wrote: >> We certainly update it an order of magnitude more often than before, but >> I don't think that's an issue. We're talking about archive recovery >> here. It's not like in normal operation where a corrupt pg_control file >> means that you lose your data. It will stop the server from starting up, >> but there's many other files that can be corrupt in a way that causes >> recovery to fail or stop too early. > > Frequent updating of pg_control causes the significant performance > degradation of archive recovery. I think that this is an issue to be fixed. > The warm-standby users (including me) care about the performance > of the standby server, because that affects the failover time, for example.
Are you actually seeing performance degradation caused by frequent pg_control updates? In the simple test scenarios I've tested, pg_control is updated only once every few WAL segments, and this with shared_buffer=32MB. With larger shared_buffers, it happens even less frequently. There's a DEBUG2-line in UpdateMinRecoveryPoint() that you can bump to LOG level if you want to observe that behavior. -- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com -- Sent via pgsql-bugs mailing list (pgsql-bugs@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-bugs
