On Sun, Apr 10, 2011 at 12:35 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Robert Haas <robertmhaas@gmail.com> writes:
>> On Sat, Apr 9, 2011 at 2:26 PM, Joshua Berkus <josh@agliodbs.com> wrote:
>>> Couldn't we have a --force option which would clear all data and tablespace directories before resynching?
>
>> What would be even more useful us some kind of support for
>> differential copy, a la rsync.
>
>> (Now I'm waiting for someone to tell me this is a pipe dream.)
>
> Not so much a pipe dream as reinventing the wheel. Why not use rsync?
It's not integrated and I doubt it's conveniently available on Windows.
One of the biggest problems with our replication functionality right
now is that it's hard to set up. We've actually done a good job
making the very simplest case (one slave, no archive) reasonably
simple, but how many PostgreSQL users do you think can manage to set
up SR + HS + archiving, with two slaves that can use the archive if
they fall too far behind the master, but with the archive regularly
trimmed to the farthest-back segment that is still needed?
We have pg_archivecleanup, but AIUI that's only smart enough to handle
the one-standby case.
Admittedly, the above is a slightly different problem, but I think it
all points in the direction of needing more automation and more ease
of use.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company