Knobit of Data modelling · K-621 · Skill

Recognises an index set not derived from access paths

What it means

Indexes missing where foreign keys, natural keys and stated access paths need them; indexes duplicated or overlapping; a non-unique index where the rule says unique. The last is a specific form of row 14; the rest are performance defects.

How it is assessed

Flags the deficient case and passes the acceptable one. Deficient: `payment.account_id` unindexed, so deleting an account scans and locks `payment`; an index on every column; `ix_party_registry_code` non-unique Acceptable: An index for each foreign key (`PHY-022`), each natural-key unique constraint, and each access path in the requirements, each index's `comment` citing which; speculative ones marked provisional

Builds on

Explains index design from access pathsK-657 · Knowledge

Needed by

None