Re: Adv. Replication, NT Oracle8, failover and Global Names

On Mon, 06 Jul 1998 21:11:20 GMT, nasof_at_my-dejanews.com wrote:

>"Before creating a database, it is important to understand that starting with
>Oracle8 Enterprise Edition, all mounted Oracle databases in a network MUST
>have unique database names."
>
>So far I have 4 instances up and running with the same db_name (all on
>different NT Servers.) How can this be true?
>
>Usually, name resolution comes down to the tnsnames.ora file. On a given
>machine I can specify the following databases all with the same db_name:
>
>db1.WORLD =
> (DESCRIPTION =
> (ADDRESS = (PROTOCOL = TCP)(HOST = 100.200.100.1)(PORT = 1521))
> (CONNECT_DATA = (SID = dbx))

-snip-

Well, it seems that your SIDs are the same, but the database name is different (db1...db4.WORLD).
Anyway, as the database name is specified at creation time, it's a no-brainer to create 4 different scripts to create the database, and ignore the issue after that.
Also, you could just as easily rename the databases after creation. Remember that SID<>NAME.

>In any case, Replication manager does not ask you for a connect string. It
>assumes that you will use Global_names (an init.ora parameter.) Does this
>mean you need to use Oracle Name server? How does else it find a Global
>named database?

Via TNSNAMES.ORA.
Probably the issue here is that the Adv.Repl.Option is doing something like

        select global_name from global_name_at_some-db-link;

and the value returned is uses as a key for a replication table lookup. IMNSHO, that's far better than the 7.x approach, in which you don't have a clue about your replicated schema and master-slave relationships. Just plan in advance and you'll be through.

>
>Can anyone offer some advice on db naming in an adv. Replication environment
>where you desire to use two databases (one as a failover and exact copy [even
>in name] to the other?)
>

Just follow the DNS standard you're using. Why [even in name] ?
>-Frank
>

--
Mauro.

(My return address is intentionally invalid; ROT13 is required. As someone already told this audience, my responses are not to be considered official technical support or advice.) Received on Tue Jul 07 1998 - 08:03:26 CDT