Re: Core team statement on replication in PostgreSQL

Hi Hannu,

Hi Hannu,

On 6/1/08 2:14 PM, "Hannu Krosing" <hannu(at)krosing(dot)net> wrote:

>
>> As a consequence, I don¹t see how you can get around doing some sort
>> of row-based replication like all the other databases.
>
> Is'nt WAL-base replication "some sort of row-based replication" ?
>
Yes, in theory. However, there's a big difference between replicating
physical WAL records and doing logical replication with SQL statements.
Logical replication requires extra information to reconstruct primary keys.
(Somebody tell me if this is already in the WAL; I'm learning the code as
fast as possible but assuming for now it's not.)

>
>> Now that people are starting to get religion on this issue I would
>> strongly advocate a parallel effort to put in a change-set extraction
>> API that would allow construction of comprehensive master/slave
>> replication.
>
> Triggers. see pgQ's logtrigga()/logutrigga(). See slides for Marko
> Kreen's presentation at pgCon08.
>
>
Thanks very much for the pointer. The slides look interesting.

Robert