Recognises a transitive dependency between non-key attributes

K-509 · Skill knobit · Activity: Derive the logical data model · Competence: Data modelling

A non-key attribute depends on another non-key attribute rather than on the key.

Can AI do this?

AI does this well Most of the tested AI models master this. 9 of 10 models master it.

Mastered means a probability of at least 90% that the model has this knobit, estimated from its graded answers. “Not shown” means the answers do not settle it either way. How the models are tested.

What it looks like in practice

Expected result: The non-key determinant and the attributes that depend on it

How it is assessed: Flags the deficient case and passes the acceptable one. Deficient: Account carries Branch Identifier and Branch Name; the name depends on the identifier, not on the account Acceptable: Branch reference entity; or, if the name must stay as it was when the account was opened, derivation saying so (LOG-018)

Also known as: Transitive dependency (3NF) (logical model)

Related knobits

Builds on

• K-556 Explains third normal form

Needed for

• K-602 Recognises logical entities merged into one table

Usually followed by

• K-533 Decomposes an entity along a functional dependency without loss

All 56 knobits of Derive the logical data model.

Source: Review checklist 05-logical, row 9; Codd 1971; Kent 1983; S&W 2.7