Re: Integrating Replication into Core

On Sat, Nov 25, 2006 at 11:05:34AM -0800, Joshua D. Drake wrote:
> Actually I don't buy this argument. The only major change in

Ok, good. So why isn't Postgres-R something we have _now_? The work
that I've seen on it, so far (and I speak as someone who invested a
significant amount of staff time, cash money, and -- frankly --
"political" credibility in software based on that idea) is that there
isn't a way to make it production-grade without pretty severe
constraints on what it can do.

It was that unhappy discovery that led me to say, "Can we please
_write down_ what we think 'replication' might require, and what the
trade-offs can be?" I'm trying to write requirements in public here;
but all I get is silence. This frustrates me partly because, as
someone who stuck his neck out to make sure Slony was released as
free software, I hear a lot of demands for features people apparently
want without much in the way of design proposals -- never mind code --
to achieve those features. When Jan delivered the initial release of
Slony, it was preceded by a design doc. I note on -hackers long
emails from (for example) Tom doing something very similar when
proposing a major feature. What I'm trying to do is to get the
replication-interested community of PostgreSQL users to say "here's
what we mean by 'replication'" before we all go off inventing the
grammar. We need to have a clue about the domain of discourse before
we start settling the variable assignments.

It seems to me that every single replication discussion on -hackers
amounts to a bunch of futile attempts by colour blind people (of
which I am one) to describe the colour 'high note', while their
interlocutors describe the sound 'red'. I'm trying to get us to say
what it would mean even to do the describing.

Specifying requirements for what software is supposed to do is one of
those thankless tasks that everyone complains is never done in the
free software community. I am offering, earnestly, to do that. I
just need a few people to tell me what _they think_ the software in
question ought to do. I set up a mailing list. I have solicited
comments. I'm not sure what else to do, but so far, I have the
positive remarks of Jose (GORDA), the remarks of Markus (which amount
to "this is a waste of time", unless I misread him), and nothing
else.

Surely, in a community that spends time on the topic of whether
replication "should be in the back end", we oughta be able to come up
with 10 or so people who are willing to say what "being in the back
end" would mean. At the moment, this trivial goal is all I'm aiming
for.

A

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