Question

I have a bit of an architecture problem here. Say I have two tables, Teacher and Student, both of them on separate servers. Since this tables share a lot of data and functionality, I would like to use this inheritance scheme and create a People table; however, I would need tho keep the Teacher table and the People records relating Teacher in one server, and the Student table and the People records relating Student in another server. This was a requirement made by the lead developer, since we have too many (and I mean too many) records for Teacher and Student, and a single database containing all of the People would collapse. Moreover, the clients NEED to have them on separate servers (sigh*).

I would really like to implement the inheritance scheme, since a lot of the funcionality could be shared among the databases. Is there any possible way to do this? any other architecture that may suit this type of problem? I’m I just crazy?

— EDIT —

Ok, I don’t really have Teachers and Students per se, I just used those names to simplify my explanation. Truth is, there are about 9 sub-tables that would inherit the super table, all of them in separate servers for separate applications, and no, I don’t have this type of database, but we have pretty low end servers for the amount of transactions we have ;). You’re right, my statements are a bit exagerated and I apologize for that, it was just to make you guys answer faster (sorry :P). The different servers are more of a business restriction than anything else (although the lead developer DID say that a common database to store the SuperTable would collapse under it’s own weight -his words, not mine :S). Our clients don’t like their information mixed with other clients information, so we must have their information on different servers -pretty stupid, but the decision-makers have spoken :(.

Answer 1

I think Paul is correct – perhaps look at your hardware infrastructure rather than your DB schema.

Using clustering, proper indexing, and possibly a data archive scheme should solve any performance problems. The inheritance scheme seems to be the best data model.

It is possible to split the data over multiple servers and keep the scheme, but I think you’d definitely have more performance problems than if you looked at clustering/proper indexing. By setting up linked servers you can do cross-server queries.

e.g. Students query

SELECT *
FROM SERVER_A.People.dbo.Persons P
    INNER JOIN SERVER_B.People.dbo.Students S
        ON P.PersonID = S.PersonID

–EDIT– As Paul said, you could perform your database separation in your abstraction layer.

E.g. have your Student class extend your Person class. In your Person class constructor, have it connect to Server A to populate whichever fields are available. In your student class constructor, have it connect to Server B (the Person attributes will already be populated by the Person constructor).