SQL Server Performance Forum – Threads Archive
Relationships between tables in different databaseCan you create relationships between 2 tables in different databases on the same server? If so, how?
You can’t use built-in referential integrity to do this, but you can use triggers to simulate this, although there is a small performance hit for doing this. —————————–
Brad M. McGehee, MVP
Also remember that such simulated rules will be potentially violated should you need to restore one database from backup and not the other.