How do I coordinate disjoint databases across SOA components?

Question

We are developing an architecture that I believe is consistent with current thinking. We plan to have a number of web-services, each with their own database. For example we'd have a web-service/database for our Customer Master, Job Scheduler, User Security Management, Billing, etc. Thewe web services would communicate with each other, as well as GUIs and batch jobs, via web service calls.
Given this structure, assume the following scenario:
The Job Scheduler ties jobs to a customer id, so the job scheduler makes web service calls to the customer master service to validate the customer id, get parameters unique to that customer, etc. Then the job scheduler writes that customer id to the job database, tying the customer id to one or more jobs.
Given this scenario, I have a couple of problems/questions:
1. How do I prevent the customer master from deleting that customer id. In a monolithic database, the DBMS tables can be set to enforce referential integrity and disallow the deletion if the id is used in another table. But in this case the customer master and job master are two different databases. I realize that I could link the databases (Oracle term) or federate them (DB2 term) so that this constraint could be enforced, but then I've just defeated one of the major goals of SOA - external entities should only know or care about interfaces to services and should not know anything about the underlying database structure, etc. Connecting the tables means that I have to coordinate with every other subsystem any time I want to change a table structure.
2. How do I generate reports from the job database that include things like customer name, address, etc. In a monolithic database, this is simple with a SQL JOIN command. But here the only thing I can see doing is hand coding web service calls for each report line to retrieve the customer name, etc.
Has anyone else had to wrestle with these problems? Am I missing something?
Thanks for any suggestions.
Bob Kendall

Answer 1

1.  In 10.1 select Tools>>Database>>Merge Database,
2.  Click on the Select A component Database Name button
3.  Go to the 10.0.1 database path, by default it's in:
C:\Documents and Settings\Your login name\Application Data\National Instruments\Circuit Design Suite\10.1
If you don't see Application Data, turn on hidden files in your Windows Explorer setting Tools>>Folder Options>>View
4.  Click Start on the Multisim Database Merger
Tien P.
National Instruments