Re: Distributed database question

"Jim Kennedy" <kennedy-down_with_spammers_at_no_spam.comcast.net> wrote in message news:eb8ab.281862$2x.78696_at_rwcrnsc52.ops.asp.att.net...
> "J Goldman" <jason_at_fc.hp.com> wrote in message
> news:3f68c63a$1_at_usenet01.boi.hp.com...
> > I'm looking for documentation pointers to learn what I need to put
 together
> > a distributed database system. I've read through "Oracle 9i Database
> > Administrator's Guide: Distributed Database Concepts" and Oracle
 Database
> > Concepts: Introduction to the Oracle Server: Distributed Databases
> > Overview", but I don't see how to do what I want.
> >
> > I would like to set up a distributed database system with location
> > transparency and a shared schema (i.e. horizontal fragmentation). I'll
> > provide a little more context: I have three databases, running on
 separate
> > systems, all of which use the identical schema. So, each has entries in
 a
> > table "foo", which are unique. I'd like to provide a global access to
 this
> > data, so a client can effectively query the set of databases. So,
 asking
> > for all entries in the "foo" table would retrieve the contents of
 db1.foo,
> > db2.foo, and db3.foo. Ideally, when all is said and done, I'm planning
 to
> > wrap this in an enterprise java bean to provide an object interface.
> >
> > Database links looked like the closest idea I could find, but they don't
> > deal well with the idea that my "foo" table has entries spread across
 the
 db
> > instances.
> >
> > A pointer in the right direction would be greatly appreciated.
> >
> > Jason
> > jason_at_fc.hp.com
> >
> >
> Why do you want them spread over 3 machines? On one machine you might
 want
> to partition the data into 3 tables and access the partition. You could
 use
> database links and views, but it is going to be very inefficient.(the link
> might have to retrieve the whole table and resolve the query on the
 database
> you are attached to - ouch, dragging all that data over a link.) Whereas
 a
> RAC might be better.
> Jim
>
Well, the first reason why they're spread over three machines is that I'm adding
this to an existing product, where the databases have already been set up like this.
This is designed such that each machine controls its own domain and one machine
cannot access another's data. Aside from security, locality of data is also relevant.
I'm just adding a global management view to collect all that data.

I'll have to read up on RAC to see if that addresses my needs. Thanks.

Regards,
Jason
jason_at_fc.hp.com Received on Thu Sep 18 2003 - 17:25:45 CEST