Example use cases
Product catalog integrity: The orders.product_id column should reference only valid products in the products table. A Lookup metric with 100% pass criteria alerts the moment any order references a non-existent product — catching orphaned records from a failed product sync before they break pricing and fulfillment.
ISO country code validation: A CRM stores country_code for every customer. A Lookup metric validates each value against a static Reference File of valid ISO 3166-1 alpha-2 codes. When a data entry team begins entering full country names instead of codes ("United States" instead of "US"), the match rate drops and Prizm alerts — surfacing a process breakdown before it corrupts segmentation reports.
Cross-source customer ID validation: A fact table’s customer_id column is validated against a CRM API. New IDs appearing in the fact table that don’t exist in the CRM surface orphaned records from a failed sync or a test data leak into production.
Use Lookup metrics for any column that represents a foreign key relationship not enforced at the database level — product codes, account IDs, country codes, status values drawn from a master data table. These violations are common in warehouses and lakehouses where FK constraints are disabled for performance.