Re: Can you create a database link back to same database instance?

From: Nigel Thomas <nigel.cl.thomas_at_googlemail.com>
Date: Tue, 10 Mar 2009 15:52:46 +0000
Message-ID: <53258cd50903100852y1ba63207x22a95c6457e23a23_at_mail.gmail.com>



Romeo

Yes, there's no problem creating loop-back database links - very common (we used to use DB links to spread workload across multiple databases in Oracle 7 / 8; works fine in test with loopback then and now). When you have both schemas in the *same *instance, you can't use a *PUBLIC *database link - because both schemas see the same link, so one of them will inevitably be wrong (or fail to create).

How about replacing it with a private database link (in at least one of the schemas)?

Regards Nigel

2009/3/10 Romeo Ybanez <raybanez_at_yahoo.com>

>
> Hi,
>
> I have this application that archives data to a different schema on the
> same instance using database link. This is probably due to the fact that in
> the Production environment it is archived to a different instance. Two
> schemas are using database links to connect to themselves. One successfully
> connects using the same service name to itself but the other does not. I am
> wondering what the trick the schema has while the other one can't connect.
>
> Example: In tnsnames.ora two service names are defined DB1 and DB2 (these
> are also the SID's)
>
> At DB1 instance a public database link is created.
>
> CREATE PUBLIC DATABASE LINK arcdb CONNECT TO arc_db IDENTIFIED BY .....
> USING "DB1";
>
> This works. But in the other instance,
>
> CREATE PUBLIC DATABASE LINK arcdb CONNECT TO arc_db IDENTIFIED BY ...
> USING "DB2";
>
> doesn't work.
>
> So it seems that you can create a database link back to the same database
> instance. If not I wonder what the trick by the other db?
>
> Thanks.
>
> Romeo Ybanez
>
>
>
>
> --
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>
>
>

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Received on Tue Mar 10 2009 - 10:52:46 CDT

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