Recognises a stored derived or summary value

K-603 · Skill knobit · Activity: Design the physical data model · Competence: Data modelling

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.

Can AI do this?

AI does this well Most of the tested AI models master this. 10 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 value, its inputs and the derivation or check it needs

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

Also known as: Stored derived or summary value (physical model)

Related knobits

Builds on

• K-510 Recognises a stored derivable attribute
• K-565 Explains derived data and point-in-time snapshots

Needed for

• K-704 Recognises a derived or copied column without a check

All 40 knobits of Design the physical data model.

Source: Review checklist 06-physical, row 3; C&B ("design representation of derived data"); E&N 17.7; S&W 12.6