Re: PostGreSQL Replication

On Sat, Jul 07, 2007 at 05:16:56AM -0700, Gabriele wrote:
> Let's have a server which feed data to multiple slaves, usually using
> direct online connections. Now, we may want to allow those client to
> sync the data to a local replica, work offline and then resync the
> data back to the server. Which is the easiest way to approach this
> problem?

Write yourself a new system that does it? To my knowledge, nobody
has yet built a production-ready system that can do this sort of
multi-master merge-back replication. I can think of possible ways
you could bodge this up using Slony-I and log shipping, but I don't
think it'd be pretty.

> resource on this topic? I've found people talking about Slony-I, what
> can you tell me on this tool? Are there other tools?

You can find out more about Slony-I at <http://www.slony.info>.

> Moreover, additionally to the previous question, let's take the case i
> do have multiple indipendent and separate server and then i want to
> upload the information of these server (actually not everything but a
> subset of the data) to another server (here we have a unidirectional
> comm, as opposed to previous bidirectional comm and we have asymmetric
> structure as opposed to the previous exact replica), what are the
> tools, documentation, best practices or other resources to approach
> this problem?

This also sounds like a multimaster problem, and again I know of no
system that currently supports what you're talking about. This is
easier to bodge together under Slony using views and such like, but
it's still not trivial. If you wish to discuss how to do this with
Slony, I suggest taking it up on that list (available from the site
mentioned above).

A

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