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

From: <nasof_at_my-dejanews.com>
Date: Tue, 07 Jul 1998 13:31:57 GMT
Message-ID: <6nt80e$tob$1@nnrp1.dejanews.com>


Thanks for the feedback Mauro.

Actually the db_name's are the same on all 4 databases.

In TNSNAMES.ora I can create as many "aliases" for databases (or the same database) that I want. This does not relate to db_name: alias1.WORLD = (DESCRIPTION =

    (ADDRESS = (PROTOCOL = TCP)(HOST = 100.200.100.2)(PORT = 1521))     (CONNECT_DATA = (SID = dbx)) )
alias2.WORLD = (DESCRIPTION =

    (ADDRESS = (PROTOCOL = TCP)(HOST = 100.200.100.2) (PORT = 1521))     (CONNECT_DATA = (SID = dbx)) )

One question: Where does a db get its info to populate the global_name table? -Frank

>On Mon, 06 Jul 1998 21:11:20 GMT, nasof_at_my-dejanews.com wrote:>
>>For Oracle8 on NT, page 9-2 of the Enterprise Edition manual states:>>
>>"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))>> )>>db2.WORLD =>> (DESCRIPTION =
>> (ADDRESS = (PROTOCOL = TCP)(HOST = 100.200.100.2)(PORT = 1521))
>> (CONNECT_DATA = (SID = dbx))>> )>>db3.WORLD =>> (DESCRIPTION =
>> (ADDRESS = (PROTOCOL = TCP)(HOST = 100.200.100.3)(PORT = 1521))
>> (CONNECT_DATA = (SID = dbx))>> )>>db4.WORLD =>> (DESCRIPTION =
>> (ADDRESS = (PROTOCOL = TCP)(HOST = 100.200.100.4)(PORT = 1521))
>> (CONNECT_DATA = (SID = dbx))>> )>
>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.>>>>
>>Each db# is resolved vi the tnsnames.ora file finding its corresponding IP
>>address, port and SID. On a given server, the db_name is unique.>>
>>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 sooner or later 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>>
>>-----== Posted via Deja News, The Leader in Internet Discussion ==-----
>>http://www.dejanews.com/rg_mkgrp.xp Create Your Own Free Member Forum>>--
>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.)>

-----== Posted via Deja News, The Leader in Internet Discussion ==----- http://www.dejanews.com/rg_mkgrp.xp Create Your Own Free Member Forum Received on Tue Jul 07 1998 - 08:31:57 CDT

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