Re: Transaction Snapshots and Hot Standby

Gregory Stark wrote:
> Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> writes:
>
>> BTW, we haven't talked about how to acquire a snapshot in the slave. You'll
>> somehow need to know which transactions have not yet committed, but will in the
>> future.
>
> I'm not sure why you need to know which ones will commit in the future.

Hmm, I phrased that badly. We need to know which transactions *might*
commit in the future, IOW, are still in progress. Because we want to
mark those as in-progress in the snapshots that are taken in the slave.
Otherwise, when they do commit, they will suddenly become visible in the
snapshots that didn't know that they were in progress.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com