Re: Integrating Replication into Core - Mailing list pgsql-hackers

On Tue, Nov 28, 2006 at 02:19:51PM +0100, Markus Schiltknecht wrote:
> (I note you don't count my version of Postgres-R (8), that might be 
> reasonable depending on your definition of 'having Postgres-R'.)

Yes; what I meant was "production-grade, ready to go."  I've played
with your code.  I'm mightily impressed that you managed to get it
working.  But I don't think it's ready for production use tomorrow in
the environments where this sort of availability is actually worth
the cost (think "money depends on this").  That's what I mean by
"have".

> and making it production grade software really takes a lot of time. IMO
> this is where replication solutions could work together, because all of
> them need to simulate a cluster somehow, to test their project. But this
> certainly has nothing to do with PostgreSQL Core.

I agree with you that such supporting tools would be a very good
thing.  Maybe nothing else is needed.  Like I said before, a negative
result is still a result.

> Another point for me is that the feedback I got on Postgres-R since
> Toronto is very close to zero. Some people haven't even noticed that
> there is Postgres-R code for 8.2. 

Well, part of the problem is there isn't much to say to code that I
can't look at.  I can play with it on the live CD, but so far the
source isn't on the web page at postgres-r.org, which is the only
source I know for it.  This makes the whole matter trickier for
potential adopters, because it's basically a black box.

> As you surely have noticed, I've been discussing forth and back with
> Bruce about replication for the documentation. I've been doing that
> because I wanted to clarify what 'replication' is, what we are talking
> about when we say 'multi-master replication' or 'data partitioning', etc..

Yes, I think those docs are very good.  But it's one thing to say,
"This is what replication means," &c., and quite another to say,
"Here are the sorts of things we plan to do, which have to work with
that pile of code over there."

> I'm sorry if this sounded that negative.

No, not negative.  Remember, as I said, if it turns out that we can't
actually come up with an outline of replication framework necessary
conditions, we have also discovered something.  That's a useful
result, because it tells us that the next thing we need to do
is figure out where the exclusive features are, so we can say "you
can have A or B, but not both."

> through and written down. And for sure I'll let you know if and how you 
> or others can help me.

Ok, thanks.

A

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When my information changes, I alter my conclusions.  What do you do sir?    --attr. John Maynard Keynes