Re: Summary and Plan for Hot Standby

Simon Riggs <simon@2ndquadrant.com>

From: Simon Riggs <simon@2ndQuadrant.com>
To: Tatsuo Ishii <ishii@sraoss.co.jp>
Cc: heikki.linnakangas@enterprisedb.com, ishii@postgresql.org, pgsql-hackers@postgresql.org
Date: 2009-11-19T09:00:05Z
Lists: pgsql-hackers
On Thu, 2009-11-19 at 17:15 +0900, Tatsuo Ishii wrote:
> > Simon Riggs wrote:
> > > Recovery does *not* take the same locks as the original statements on
> > > the master took. For example, the WAL record for an INSERT just makes
> > > its changes without acquiring locks. This is OK as long as we only allow
> > > read-only users to acquire AccessShareLocks. If we allowed higher locks
> > > we might need to do deadlock detection, which would add more complexity.
> > 
> > But we *do* allow higher locks than AccessShareLocks, as Tatsuo-sans
> > example shows. Is that a bug?
> 
> Sorry for confusion. My example is under normal PostgreSQL, not under
> HS enabled.

Are you saying you want it to work in HS mode?

Why would you want to PREPARE an INSERT, but never execute it?

-- 
 Simon Riggs           www.2ndQuadrant.com