Re: draft RFC: concept for partial, wal-based replication

[Stefan Kaltenbrunner <stefan(at)kaltenbrunner(dot)cc>]

Andres Freund wrote:
> On Monday 30 November 2009 03:57:11 Itagaki Takahiro wrote:
> > Boszormenyi Zoltan <zb(at)cybertec(dot)at> wrote:
> > > we tried to discuss on a lower level what should be needed
> > > for a partial replication based on streaming replication.
> > We need to discuss a "partial recovery" before the partial replication.
> If you do the filtering on the sending side you dont actually need partial 
> recover in the sense that you filter in the rmgr or similar.
>
> Or do I miss something?

the question is if filtering on the sending side is actually the "right 
thing" to do.
It increases the overhead and the complexity on the master, especially 
if you think about different (partial) replication agreements for 
different slaves and it might also be hard to integrate with the planned 
sync/async modes.
On the other hand if you filter on the master you might be able to avoid 
a lot of network traffic du to filtered wal records.
I think for a first step it might make more sense to look into doing the 
filtering on the receiving side and look into actual integration with SR 
at a later stage.


Stefan