Re: Sync Rep Design

Robert Haas <robertmhaas@gmail.com>

From: Robert Haas <robertmhaas@gmail.com>
To: Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>
Cc: Jeff Janes <jeff.janes@gmail.com>, Simon Riggs <simon@2ndquadrant.com>, pgsql-hackers@postgresql.org
Date: 2011-01-01T14:15:45Z
Lists: pgsql-hackers
On Sat, Jan 1, 2011 at 9:03 AM, Stefan Kaltenbrunner
<stefan@kaltenbrunner.cc> wrote:
> that is exactly my point - if have no guarantee that your SYNC standby is
> actually sync there is no use for it being used in business cases that
> require sync replication.
> If we cannot support that usecase I would either like to see us restricting
> to only one sync capable standby or by putting a big CAVEAT into the docs
> saying that sync replication in pg only is a hint and not a guarantee that
> might or might not be honored in the case of more than one standby.

I think it's clear that different people want to different things.  I
understand Simon's point, but I think the point Stefan and Jeff are
making is equally valid.  I think the solution is:

- Simon gets to implement his version first because he's writing the
code.  If someone else writes the code then they get to pick.

- Whoever wants to make the other thing work can write a patch for that after.

- The docs should not allege that either setup is preferable to the
other, because there is not now and will never be consensus that this
is in fact true.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company