Re: DB Links from ORACLE 6 to 7.3

Marc Lafontaine wrote:

> We have a application which run on a ORACLE RDBMS v6.xxx and we also have
> DB Links set up to talk to another V6.xx database. The other database was
> recently upgraded to V7.3.xx. Now when we try to access to other database
> we are getting two-task errors. Is there a simple fix to are DB LINKS? What
> is wrong and can someone help me

 I'm afraid you have got rather a large problem here as v6 doesn't support SQL*Net v2 and v7.3 doesn't support SQL*Net v1.

I have encountered this problem at a site once before, where a new implementation required the use of v7.3 features but still needed to access/be accessed by a v6 database. The way I got round it was to create an intermediary v7.2 database which appeared to be the v6 database from the v7.3 perspective and vice versa. I then created a set of synonyms in the v7.2 database for all the tables in the v6 and v7.3 databases. Each synonym actually included the required database link to re-route the query to the appropriate table e.g.

on v7.3 instance

create database link v6db using 'v7.2def';

on v6 instance

create database link v7db using 'T:host:v7.2def'; -- its been a while so I apologise if the sql*net v1 syntax isn't quite right

on v7.2 instance

create database link v6db using 'T:host:v6def'; create database link v7db using 'v7.3def';

create synonym v6tab for v6tab_at_v6db;
create synonym v7tab for v7tab_at_v7db;

therefore executing the query;
select * from v6tab_at_v6db;

on the v7.3 instance will seemlessly return the rows from the v6 database and vice versa.

Hope this helps,

Ian Received on Wed Nov 26 1997 - 00:00:00 CST