Re: Replication or Database Link ? (Web-Architecture with EJB)

Uuups, just figured out that there is a third solution which is kind of nice. In Java you can call a stored procedure that resides on a different machine but is connected via a database link: ...call stored_procedure_at_CALLDB(?,?)...

I assume this also works with PL/SQL.

Nevertheless, any comments regarding the feasibility ?

Thanks, Timo.

In article <7pef68$v56$1_at_nnrp1.deja.com>,   tsalzsie_at_hotmail.com wrote:
> Folks,
>
> thanks for all your replies.
> To bring more detail into the discussion and add one more aspect:
> Our WEBDB is in fact a database that will be accessed by internet
users.
> Security-wise both databases are behind a firewall and the WEBDB is
> accessed from an application server via IIOP. That means that our
> WEBDB is an Oracle8i with EJB-logic running inside the database and
the
> CALLDB is an Oracle8.0.5 both under Solaris.
>
> Now, we provide additionally some stored procedures that work on our
> MEMBER table and need to be accessed from some other PL/SQL stored
> procedures as well as from the EJB. Using a database link, that would
> mean that I need to call a stored procedure on another database via a
> database link. How ?
>
> I see the following solutions - neither one seems to be very
attractive:
>
> 1. Duplicate the stored procedures and replace e.g. "select * from
> member" by "select * from member_at_CALLDB".
> 2. Let the EJB make an additional connection to the CALLDB and execute
> the stored procedure on CALLDB.
>
> I believe that the latter one seems to be more appropriate ?
>
> Any comments or ideas ?
>
> Thanks again, Timo.
>
> In article <EjBs3.152$5W.3156230_at_news1.van.metronet.ca>,
> "DET" <NotValidBecauseOfSpammers_at_ipipeline.net> wrote:
> > First problem:
> >
> > With synchronous replication, if one database goes down, you can't
do
> > updates to the other until you either bring up the downed database
or
> turn
> > off the synchronous replication -- which brings up synchronizing
> problems
> > when you finally fix the crashed database.
> >
> > I assume one database is on the internet and one is on your internal
> LAN.
> > How are you getting the connection across the firewall? what
security
> are
> > you implementing?
> >
> > tsalzsie_at_my-deja.com wrote in message
<7ots95$jes$1_at_nnrp1.deja.com>...
> > >Pete,
> > >
> > >thanks for your reply. There are some semantic as well as security
> > >reasons that we need two databases. The databases are in the same
> > >network (in other words in the same data center) and afaik are
> connected
> > >via a 100 Mbit network.
> > >One of the reason some people in our department tend to use
> synchronous
> > >replication is availability - in other words, WEBDB is still
availabe
> > >when CALLDB crashes and vice versa. However, I'm not sure how to
> handle
> > >these large batch jobs at night - how replication reacts or if it
> makes
> > >sense to disable replication while these batch jobs are running.
> > >So, database links seems to be the most appropriate solution with
> > >respect to simplicity, reliability and performance.
> > >
> > >Any other recommendations or things we should look for ?
> > >
> >
> >
>
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>

Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't. Received on Wed Aug 18 1999 - 09:31:55 CDT