Using SQL Server, can a constraint prevent duplicate combinations across the first three columns, or is a composite primary key required?
In my experience, enforcing uniqueness across multiple columns can be achieved without necessarily using a composite primary key. A unique constraint on the first three columns will effectively prevent duplicate combinations while allowing other design considerations to be managed independently. This approach offers flexibility if you want to use alternative keys or include additional attributes in your table. It is important to analyze your specific requirements, as a composite primary key might not be ideal if there is a need for surrogate keys or if the business logic demands a different strategy for managing relationships across tables.