Designing a Conformed Dimension

The interviewer will ask you to design a dimension that serves multiple fact tables. The trap: candidates over-stuff the dimension with domain-specific attributes that create unnecessary coupling. The signal they are looking for is whether you know what belongs in the conformed core versus what belongs in an extension. The Date Dimension: The Example Every Interviewer Expects Your conformance answer: 'Every fact table references the same dim_date via date_sk. When I GROUP BY dim_date.quarter, I get the same quarter definition whether I am querying sales, returns, or marketing. That is conformance in action: one definition, shared everywhere.' Say 'one definition, shared everywhere.' That is the sentence the interviewer is listening for. What Belongs in the Conformed Core vs the Extension Y