Re: Bidirectional replication

On Thu, May 05, 2011 at 08:13:55PM -0700, John R Pierce wrote:
> On 05/05/11 8:05 PM, Joshua Tolley wrote:
>> Actually, Bucardo doesn't do statement replication. It, like Slony for
>> instance, replicates data, not SQL statements. And as you pointed out, it does
>> do bidirectional replication in a way that's sufficient for some use cases.
>
> does it use triggers for replication, similar to Slony, then?
> obviously, it can't be doing WAL level replication or it wouldn't be
> able to do any sort of master-master.

Exactly. It doesn't function exactly like Slony does under the hood, of
course, but it is trigger based. One notable difference between Bucardo and
Slony is that whereas Slony's triggers store the entire row data in a separate
log table when something changes, Bucardo stores only the primary key. As a
result, Bucardo doesn't apply each transaction to the replica databases, but
rather a set of all transactions that took place on the source since the last
time it synchronized things. For whatever that's worth.

--
Joshua Tolley / eggyknap
End Point Corporation
http://www.endpoint.com