Re: Concurrent/Parallel Execution

I agree with Robert, cross database union is what you need. Believe it or not, this is not uncommon to do, and since this is theory only (Keeping it Simple), here is what can be done:

create database links to each target database. Write a view to do you union:
select my_column from my_table_at_orcl1
union
select my_column from my_table_at_orcl2
union
select my_column from my_table_at_orcl3;

A better way to do this is create a data warehouse environment:

create database links to each system
create materialized views on each target table create a materialized view on top of all of them that has your specific where clause info, summaries, etc...

you don't need an "Army" of contractors, just a day or so to do this and test : )

Mike Fullerton
Oracle DBA

Robert Klemme wrote:
> On 22.11.2006 17:59, ihb wrote:
> > "Robert Klemme"
> > No, not that complicated...not JOIN,
> > I try to present a very simple case....
> > e.g. "select * from emp_n"
> > from each DB....the requirement is to COMBINE the result sets (like UNION)
>
> Well yes, ok then cross database union. :-)
>
> >> Plus, you did not state your business requirements instead you come up
> >> with a solution and....
> >
> > I "come up with a solution" ????? <scratch-head>
> >
> > This is not requitrement ?
> > "Say data is everywhere....there are n databases (on n servers)
> > In app I need to query each DB and COMBINE the results."
>
> Oh, it sounded to me as if you were starting to set up this system. So
> you have /existing/ databases you want to get data from. In that case
> DB links that have been suggested might be a solution.
>
> robert
Received on Wed Nov 22 2006 - 12:21:08 CST