Which anomaly occurs when vendor information is tied to each item, causing inconsistent updates if a vendor's details change?

Which anomaly occurs when vendor information is tied to each item, causing inconsistent updates if a vendor's details change?

• A. Insert anomaly
• B. Delete anomaly
• C. Update anomaly
• D. Key anomaly

Answer: (C)

Redundancy of vendor information in every item row leads to an update anomaly. When a vendor’s details change, you have to modify multiple rows. If any one row is missed, the database ends up with inconsistent vendor data across items from the same vendor. Normalizing by placing vendor details in a separate table and linking items to that table with a key eliminates this duplication and ensures updates happen in one place. This isn’t about inserting new vendors without items (insert anomaly) or deleting an item erasing vendor data (delete anomaly).

Redundancy of vendor information in every item row leads to an update anomaly. When a vendor’s details change, you have to modify multiple rows. If any one row is missed, the database ends up with inconsistent vendor data across items from the same vendor. Normalizing by placing vendor details in a separate table and linking items to that table with a key eliminates this duplication and ensures updates happen in one place. This isn’t about inserting new vendors without items (insert anomaly) or deleting an item erasing vendor data (delete anomaly).