Re: max_standby_delay considered harmful
Robert Haas <robertmhaas@gmail.com>
From: Robert Haas <robertmhaas@gmail.com>
To: Greg Stark <gsstark@mit.edu>
Cc: Greg Smith <greg@2ndquadrant.com>, Tom Lane <tgl@sss.pgh.pa.us>, Andres Freund <andres@anarazel.de>, pgsql-hackers@postgresql.org, Bruce Momjian <bruce@momjian.us>, Simon Riggs <simon@2ndquadrant.com>, Josh Berkus <josh@agliodbs.com>
Date: 2010-05-09T16:52:37Z
Lists: pgsql-hackers
On Sun, May 9, 2010 at 12:47 PM, Greg Stark <gsstark@mit.edu> wrote: > On Sun, May 9, 2010 at 4:00 AM, Greg Smith <greg@2ndquadrant.com> wrote: >> The use cases are covered as best they can be without better support from >> expected future SR features like heartbeats and XID loopback. > > For what it's worth I think deferring these extra complications is a > very useful exercise. I would like to see a system that doesn't depend > on them for basic functionality. In particular I would like to see a > system that can be useful using purely WAL log shipping without > streaming replication at all. > > I'm a bit unclear how the boolean proposal would solve things though. > Surely if you set the boolean to recovery-wins then when using > streaming replication with any non-idle master virtually every query > would be cancelled immediately as every HOT cleanup would cause a > snapshot conflict with even short-lived queires in the slave. It sounds to me like what we need here is some testing. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise Postgres Company