Knobit of Data modelling · K-502 · Skill

Recognises an update anomaly in a logical data model

What it means

One fact is stored in several rows, so a change must be repeated and a partial change leaves the data contradicting itself.

How it is assessed

Flags the deficient case and passes the acceptable one. Deficient: Account holder address held on every Account; the customer moves and three of their five accounts are updated Acceptable: Address held once on Party; Account reaches it through Account Holder

Builds on

Explains the insertion, update and deletion anomaliesK-553 · Knowledge

Needed by

Recognises an unmanaged duplicate columnK-601 · Skill