On Tue, 2005-12-06 at 10:03 -0200, Gustavo Tonini wrote:
> But, wouldn't the performance be better? And wouldn't asynchronous
> messages be better processed?
At least for synchronous multi-master replication, the performance
bottelneck is going to be the interconnect between the nodes -
integration of the replication logic into the backend most probably
doesn't affect performance that much.
I'd rather like to ask Jan what different needs for replication he
discovered so far. And how he came to the conclusion, that it's not
possible to provide a general solution.
My point for integration into the backend is flexibility: obviously the
replication code can influence the database much more from within the
backend than from the outside. For example running one complex query on
several nodes. I know, this a very advanced feature - currently it's not
even possible to run one query on multiple backends (i.e. processors of
a multi-core system) - but I like to plan ahead instead of throwing away
code later. For such advanced features you simply have to dig around in
the backend code one day. Of course you can always add hooks, but IMHO
that only complicates matters.
Is there some discussion going on about such topics somewhere? What's up
with slony-2? The wiki on slony2.org still doesn't provide a lot of
technical information (and obviously got spammed BTW).
Regards
Markus