Recognises logical entities merged into one table
Two logical entities, usually a parent or reference entity and its child, stored as one table. One kind of fact can no longer be recorded without the other, and deleting the last child deletes the parent.
Can AI do this?
Not tested yet
No AI benchmark covers this knobit yet. New results are announced in the Can AI Do the Job? newsletter.
What it looks like in practice
Expected result: The merged entities and the facts they now tie together
How it is assessed: Flags the deficient case and passes the acceptable one. Deficient: account absorbs branch (branch_id, branch_name); a newly opened branch cannot be recorded until an account is serviced there, and deleting the last account serviced there deletes the name Acceptable: ref_branch stays the system of record; a merged structure exists only as a dimension or view built from it
Also known as: Tables merged (physical model)
Related knobits
Builds on
- K-509 Recognises a transitive dependency between non-key attributes
- K-651 Explains controlled denormalisation
All 40 knobits of Design the physical data model.
Source: Review checklist 06-physical, row 2; Codd 1971; Kent 1983; Fagin 1981; C&B; S&W 12.6