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Posted to ojb-user@db.apache.org by Angus Berry <an...@elken.com> on 2004/08/29 01:19:40 UTC
Re: 2 Databases connected to OJB??
Armin,
The simpler option#2 below, is working for me... thanks.
I wonder if you could describe the syntax to connect to the second DB
using OQL instead of the Native PB.
thanks again...
On Wed, 2004-04-21 at 04:20, Armin Waibel wrote:
> Hi Angus,
>
> Angus Berry wrote:
>
> > I'm hoping someone can help me out here. I'm running OJB quite happily,
> > but now I need to add a second Database.
> >
> > The second database is akin to a data warehouse. It contains a large
> > amount of data that I only want to read from for reference purposes. In
> > the future, other applications may also independently access this
> > database outside of my control, hence I don't want to mingle it's tables
> > with my application specific database.
> >
> > Can anyone suggest how I should configure this or a strategy to achieve
> > the above
> >
>
> Generally speaking you have two alternatives:
>
> - Setup a separate repository file repositoryWarehouse.xml (with own
> sub-files for connection repositoryWarehouse_database.xml and object
> metadata....) and read this new repository at runtime before the first
> use. Info about how to read and merge metadata can be found here
> http://db.apache.org/ojb/api/org/apache/ojb/broker/metadata/MetadataManager.html
>
> - A much simpler soulution will be to extend the existing repository
> file by using separate sub-files. Create a new
> repositoryWarehouse_database.xml and define the
> jdbc-connection-descriptor for the warehouse DB (as you only want to do
> read-only operations the sequence manager should be never used, but I
> recommend to set SequenceManagerInMemoryImpl as sequence manager, this
> implementation doesn't need any external tables).
> Create a repositoryWarehouse_user.xml and add all class-descriptor used
> to access the warehouse tables (be aware of name conflicts with existing
> class-descriptors).
>
> You can access the warehouse DB (not default connection, attribute
> 'default-connection' in jdbc-connection-descriptor have to be 'false' in
> this case) by pass a PBKey to the PBF:
>
> PBKey pbWarehouse = new PBKey(jcdAliasWarehouse,username, passwd);
> PersistenceBroker broker =
> PersistenceBrokerFactory.createPersistenceBroker(pbWarehouse);
>
> regards,
> Armin
>
> > thanks...
> >
> >
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> >
> >
> >
>
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Re: 2 Databases connected to OJB??
Posted by Armin Waibel <ar...@apache.org>.
Hi Angus,
Angus Berry wrote:
> Armin,
>
> The simpler option#2 below, is working for me... thanks.
>
> I wonder if you could describe the syntax to connect to the second DB
> using OQL instead of the Native PB.
>
Do you mean by the odmg-api? If so try
http://db.apache.org/ojb/docu/faq.html#lookupODMG
But the odmg-api is not designed to use different DB (concurrently) with
the same thread. In this case you should use two separate
odmg.Implementation instances and open for each DB a odmg.Database
instance.
regards,
Armin
> thanks again...
>
> On Wed, 2004-04-21 at 04:20, Armin Waibel wrote:
>
>>Hi Angus,
>>
>>Angus Berry wrote:
>>
>>
>>>I'm hoping someone can help me out here. I'm running OJB quite happily,
>>>but now I need to add a second Database.
>>>
>>>The second database is akin to a data warehouse. It contains a large
>>>amount of data that I only want to read from for reference purposes. In
>>>the future, other applications may also independently access this
>>>database outside of my control, hence I don't want to mingle it's tables
>>>with my application specific database.
>>>
>>>Can anyone suggest how I should configure this or a strategy to achieve
>>>the above
>>>
>>
>>Generally speaking you have two alternatives:
>>
>>- Setup a separate repository file repositoryWarehouse.xml (with own
>>sub-files for connection repositoryWarehouse_database.xml and object
>>metadata....) and read this new repository at runtime before the first
>>use. Info about how to read and merge metadata can be found here
>>http://db.apache.org/ojb/api/org/apache/ojb/broker/metadata/MetadataManager.html
>>
>>- A much simpler soulution will be to extend the existing repository
>>file by using separate sub-files. Create a new
>>repositoryWarehouse_database.xml and define the
>>jdbc-connection-descriptor for the warehouse DB (as you only want to do
>>read-only operations the sequence manager should be never used, but I
>>recommend to set SequenceManagerInMemoryImpl as sequence manager, this
>>implementation doesn't need any external tables).
>>Create a repositoryWarehouse_user.xml and add all class-descriptor used
>>to access the warehouse tables (be aware of name conflicts with existing
>>class-descriptors).
>>
>>You can access the warehouse DB (not default connection, attribute
>>'default-connection' in jdbc-connection-descriptor have to be 'false' in
>>this case) by pass a PBKey to the PBF:
>>
>>PBKey pbWarehouse = new PBKey(jcdAliasWarehouse,username, passwd);
>>PersistenceBroker broker =
>>PersistenceBrokerFactory.createPersistenceBroker(pbWarehouse);
>>
>>regards,
>>Armin
>>
>>
>>>thanks...
>>>
>>>
>>>---------------------------------------------------------------------
>>>To unsubscribe, e-mail: ojb-user-unsubscribe@db.apache.org
>>>For additional commands, e-mail: ojb-user-help@db.apache.org
>>>
>>>
>>>
>>
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>>
>>
>
>
>
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>
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