Re: logical changeset generation v3 - comparison to Postgres-R change set format - Mailing list pgsql-hackers

On 11/16/2012 03:14 PM, Andres Freund wrote:
> Whats the data type of the "COID" in -R?

It's short for CommitOrderId, a 32bit global transaction identifier,
being wrapped-around, very much like TransactionIds are. (In that sense,
it's global, but unique only for a certain amount of time).

> In the patchset the output plugin has enough data to get the old xid and
> the new xid in the case of updates (not in the case of deletes, but
> thats a small bug and should be fixable with a single line of code), and
> it has enough information to extract the primary key without problems.

It's the xmin of the old tuple that Postgres-R needs to get the COID.

Regards

Markus Wanner