[Info-Ingres] Multi-database table references

[Raghavan]

On Sep 24, 12:19 pm, "Roy Hann" <specia... at processed.almost.meat>
wrote:
> "Raghavan" <rajiragha... at gmail.com> wrote in message
>
> news:1190611013.872340.6100 at 50g2000hsm.googlegroups.com...
>
> > I have a legacy application running for more than15 yrs. Now I am
> > wanting to use the concept of creating multi-databses for various
> > reasons.
>
> I don't know how well-defined the term "multidatabase" is defined, but I
> sort of think it implies a mix of products.  Something like say, some Oracle
> databases and some MS SQL Server databases and some Ingres databases all
> tied togther (possibly using Ingres/Star and suitable gateways).  Is that
> what you are intending?  Or do you want to distribute the tables of one
> existing Ingres database amongst multiple future Ingres databases (i.e. a
> single product, with a single concurrency control model)?
>
> > The problem is,
> > 1. I have to segregate the applications to various databases.
> >    and assign tables pertainign to those databases.
>
> That could be a problem sure.
>
> > 2. In the current applciations as it is a single production database,
> > i will have to introduce the concept of aliases for various tables to
> > minimise the coding of the existing applications.
>
> Ingres supports table synonyms.
>
> > Has anyone handled such a scenario?
>
> I am not clear what the scenario is.  Are you just breaking up one big
> database into more manageable independent pieces, or do you need to operate
> the pieces as a single federated database with distributed (2PC)
> transactions?
>
> > Can anyone help me?
>
> I don't know.  What is the business problem to be solved?  What is the
> business case for doing it (I.a. how much trouble can the solution be before
> it offsets the benefit)?  What mix of products?  Local databases or
> geographically distributed?   How many users?  What is the mix of on-line
> and batch processing?  What are the response-time expectations?
>
> Whatever it is you have in hind, it sounds like it won't be trivial.  Even
> using Star to run a homogeneous federation of Ingres databases is
> problematic.  Adding Enterprise Access Gateways to the mix takes it to a
> whole new level.  I have done it when there was no choice, but I don't think
> I would ever set out to do it if I didn't absolutely have to, and the
> business case would have to be unassailable.
>
> Roy

Hello!

You have identified the problem, yes, I want to just break up one big
database into more manageable independent pieces.

Mrs Raghavan