Re: Why dbms_defer_sys.schedule_push with updateable snapshots

From: Frank <fvanbortel_at_netscape.net>
Date: Sat, 11 Jan 2003 20:00:58 +0100
Message-ID: <3E2069EA.7050803@netscape.net>

Jake wrote:
> Hi,
>
> I'm working in a 8.1.7.4 on Win2k environment
>
> I'm setting up some updateable snapshots. I have built a refresh group and
> put my objects within it. I don't understand why I have to also schedule
> push and purge jobs.
>
> The refresh group has a schedule, and as I understand, when the group
> refreshes it pushes it's changes to the master and then pulls all the
> changes at the master.
>
> What's the push job accomplishing? What's the purge job purging? I've
> read/reread the
> Oracle8i Replication
> Oracle8i Distributed Database Systems
>
> manuals, but I can't find any enlightenment.
>
> thanks
> jake
>
>

afaik, the push job pushed out deferred transactions (i.e. transactions not cascaded to all snapshots), the purge job purges transaction/data records from the master tables, only for those transactions that have been propagated to all registered snapshots.
If you picture refresh on demand, the mechanism, and the need for it, becomes obvious.

Grtz, Frank Received on Sat Jan 11 2003 - 13:00:58 CST