Knobit of Data modelling · K-816 · Skill

Recognises one decimal scale for every currency

What it means

`DECIMAL(n,2)` on an amount column in a table that is not single-currency. ISO 4217's minor-unit table is not a constant 2: JPY has 0, KWD and BHD have 3. Two decimals silently round a dinar instruction and store two meaningless zeros on a yen one.

How it is assessed

Flags the deficient case and passes the acceptable one. Deficient: `fact_payment.instructed_amount DECIMAL(14,2)` with `account_currency_code` ranging over ISO 4217; a KWD payment of 12.345 is stored as 12.35 and the original instruction can no longer be reproduced Acceptable: Scale set to the widest minor unit in scope (`DECIMAL(16,3)`), the per-currency minor-unit digits held in the currency reference table, and a DQ rule that an amount's minor units match its currency. Or the single-currency scope stated in the column `comment`, so the next reviewer knows `2` was a decision

Builds on

Recognises a physical domain differing from the logical domainK-617 · Skill
Explains currency minor unitsK-853 · Knowledge

Needed by

None