Re: [RFC][PATCH] wal decoding, attempt #2 - Design Documents (really attached)

On Mon, Oct 15, 2012 at 08:26:08PM +0200, Andres Freund wrote:
> > > > I do not personally believe that a WAL decoding solution adequate to
> > > > drive logical replication can live outside of core, at least not
> > > > unless core exposes a whole lot more interface than we do now, and
> > > > probably not even then.  Even if it could, I don't see the case for
> > > > making every replication solution reinvent that wheel.  It's a big
> > > > wheel to be reinventing, and everyone needs pretty much the same
> > > > thing.
> > > 
> > > Unsurprisingly I aggree.
> > > 
> > > > That having been said, I have to agree that the people working on this
> > > > project seem to be wearing rose-colored glasses when it comes to the
> > > > difficulty of implementing a full-fledged solution in core.
> > > 
> > > That very well might be true. Sometimes rose-colored glasses can be quite
> > > productive in getting something started...
> > > 
> > > Note at this point were only want wal decoding, background workers and
> > > related things to get integrated...
> > 
> > Well, TODO does have:
> > 
> > 	Move pgfoundry's xlogdump to /contrib and have it rely more closely on
> > 	the WAL backend code
> 
> Uhm. How does that relate to my statement?
> 
> The xlogreader code I submitted does contain a very small POC xlogdump with 
> almost no code duplication. It needs some work to be really useful though.

I just meant that dumping xlog contents is something we want to improve.

> > I think Robert is right that if Slony can't use the API, it is unlikely
> > any other replication system could use it.
> 
> I aggree and I don't think I have ever said something contrary. I just don't 
> want to be the only one working on slony integration. I am ready to do a good 
> part of that, but somebody with slony experience needs to help, especially on 
> consuming those changes.

Agreed.

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + It's impossible for everything to be true. +