Stage 6: Design the physical data model
Knobit of Data modelling · K-603 · Skill
Recognises a stored derived or summary value
What it means
A column or table holding a value computed from other stored data, written separately from its inputs, so the two can disagree. The physical form of logical row 10.
How it is assessed
Flags the deficient case and passes the acceptable one. Deficient: `loan.total_repayment_amount` kept by the application alongside `instalment`; an instalment is corrected and the total is not. `account_balance_monthly_total` reloaded nightly, with nothing saying as of when Acceptable: A generated column or a view; otherwise `derivation` naming the rule and the refresh mechanism, and a DQ rule comparing stored and computed values. A summary table carries its as-of timestamp
Builds on
- Recognises a stored derivable attributeK-510 · Skill
- Explains derived data and point-in-time snapshotsK-565 · Knowledge