Re: Snapshot log overhead

Dave

Snapshot logs are designed to minimize the impact of replication. If you are using fast refreshes, Oracle will just take the rows from the log rather than the whole table (complete refresh).

I think your question though is really more pointed toward when does trigger based replication become an overhead compared to log based replication, like SharePlex or Oracle's own standby database. That is virtually impossible to answer because it depends on so many things, as you point out. The best way to determine whether there is too much impact is to volume test the environment.

The other thing that will have a major impact here is the version you're on. As each new release comes out, the performance is better and better. With Oracle8 for example, there were a lot of improvements made like minimizing communication, parallelization of replication and so on.

HTH. Pete

dpurrington_at_my-deja.com wrote:

> What is the overhead involved with snapshot logs? To put this another
> way, at what point do snapshot logs become an unworkable solution? I'd
> rather not have to involve a third-party product (like SharePlex by
> Quest), although I will if I have to.
>
> Obviously this has something to do with the number of tables
> replicated, the frequency of refresh, and the volume of data. Can
> anyone nudge me in the right direction here? I definitely don't want
> to significantly impact the master database, but the target database is
> for reporting purposes so timeliness is not critical. SharePlex
> replication (and products like it) seem more appropriate for a hot-
> standby, bidirectional, or disaster recovery solution.
>
> Thanks,
> Dave P.
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.

Received on Sat Nov 20 1999 - 20:12:11 CST