On 11/2/2004 10:07 AM, Andrew Sullivan wrote:
> On Mon, Nov 01, 2004 at 04:35:00PM -0500, Dave Chapeskie wrote:
>> 
>> Basically I would like the ability for a large replicated table to
>> have distributed origins where each row has a specific origin which is
>> allowed to modify the row and propagates changes to all slaves.  Each
>> row only needs to have a single origin/master however (i.e. I don't need
>> full multi-master support).
>> 
>> I'm hoping some of the developers can comment on
>> 
>> (a) How difficult would it be for me to add this to SlonyI?  Is it even
>>     feasible?
> 
> Sure.  I know Joe Conway does something like this with dbmirror. 
> But. . .
> 
>> (b) If I were to produce a patch that implements this would it be
>>     considered for inclusion into SlonyI at all or do you intend to
>>     restrict these types of features to SlonyII.
> 
> . . .what you're talking about is not multi-master.  Multi-master is
> intended to be a full-blown cluster, write-in-any-db,
> see-it-everywhere system.
> 

And he clearly said he doesn't need full MM.

Anyhow, it would require to combine the log and the "deny update on 
subscriber" triggers into one, that then checks on call if the row 
called for is a local row or not. It also requires fundamental changes 
in the rest of the logic, like the way ENABLE_SUBSCRIPTION travels with 
respect to cascading. Or how to deal with MOVE_SET. It will not be a 
small change.


Jan

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