Best approach to Architect the integration of two separate databases?

Question

I\'ve ran into the following questions at work, and I don\'t have the experience or knowledge in order to answer them, I\'m hoping that some of you wiser folk may be able to poi

Answer 1

It depends very much on what you mean by integration.

• If you just want to combine the various tables for reporting purposes then you should look at some process to Extract and Load selected data from each system into a Datawarehouse. You will need to define a common data model for both systems. This data can then be ised for reporting.
• If you want one system to invoke the services or retrieve data from another system then I would recommend you use the classic SOA pattern. Expose the functions you want to make available to the other system as services via SOAP, REST messages or similar. And get the client systems to use these methods and only these methods to send or retrieve data.

Avoid if at all possible looking directly into the foreign systems database, replicating data from one system to the other, or making direct API calls to the source system. The guiding principle should be "if I replace system X with system SuperX how easy would it be to keep the other systems working".