Stage 7: Derive data quality rules
Knobit of Data modelling · K-709 · Skill
Recognises a check unable to fail
What it means
A check of something the database already guarantees on that target — completeness of a `NOT NULL` column on Postgres, uniqueness of an enforced primary key — or of a definitional rule that no data can break. It always passes, inflates the quality score, and teaches people that DQ results are decoration.
How it is assessed
Flags the deficient case and passes the acceptable one. Deficient: `DQ-002: IBAN present`, `account_identifier NOT NULL` on Postgres, threshold 100 %, green forever Acceptable: Removed; or, where the constraint is enforced on one target and not another, scoped in its `comment` to the target that needs it. A stored derivation is checked as a stored column (row 4), not as a definition
Builds on
- Explains rule enforcement mechanisms and platform enforcementK-356 · Knowledge
- Explains alethic and deontic modality of rulesK-352 · Knowledge
Needed by
- None