Re: Selects via DB Links - Special Tuning Considerations

Comments embedded.
Bob Jones wrote:
> "Steven Kondolf" <skondolf_at_nospam.rochester.rr.com> wrote in message
> news:ek61p11tplu1ghrt7srtmum7hodrp1pf55_at_4ax.com...
> > We have an old 8.0.6.3 database running on HPUX 11 that currently
> > contains our Oracle Applications 11.0.3 instance (both database and
> > APPL_TOP) as well as a data warehouse schema. We are beginning to run
> > out of physical room and plan on moving the data whse schema over to a
> > Linux server running 10g (10.2.0.1) and Redhat AS 4.0. This will also
> > free up processing resources on the old HP box.
> >
> > As we cannot upgrade our 11.0.3/HP box until next year due to business
> > reasons (read MONEY), our 8.0.6 box will still contain the
> > jobs/reports/scripts etc. Our plan is to build a db link from the
> > 8.0.6 box to the 10.2 box and change our code to perform our
> > processing via this db link.
> >
> > Are there any special tuning considerations relative to db links,
> > sqlnet, etc. that I should be looking at? I've found notes on
> > Metalink commenting on tuning sqlnet by setting the SDU and TDU sizes
> > but I've also found notes that state this would be of limited value
> > and the "default settings" are adequate in the vast majority of
> > situations.
> >
> > I don't have a lot of Oracle8 documentation available and am currently
> > having trouble connecting to tahiti.oracle.com to see if there's any
> > docs for 8 there. Thanks for any help or insights given.
> >
> > Steve
>
> You might run into problems since version 8 is no longer supported.

That is the least of his worries, as 8.0.x will not 'converse' with 10g of any sort via SQL*net. Not directly, anyway. Such a configuration requires an intermediate version such as 9.0.1 or 9.2.0 to act as a 'gateway'. The earliest release which will connect to 10g directly is 8.1.7.x.

> Depending on your applications, this change could generate a lot of network
> traffic, and make your queries run slower.
>

Yes, his queries will run so slowly as to return no results since there will essentially be *no* network traffic generated between 8.0.6 and 10.2.0 because the SQL*Net versions are incompatible.

> Oracle docs are all over the internet, not just on tahiti.

Funny you didn't find this information in those docs ....

David Fitzjarrell Received on Fri Dec 02 2005 - 22:33:53 CST