Skilirium

6. etapp: Füüsilise andmemudeli kujundamine

Kompetentsi Andmete modelleerimine knobit · K-616 · Oskus

Recognises a changeable value list fixed in the DDL

Mida see tähendab

A value set implemented as `CHECK (... IN (...))` or an enum type although the business changes it. Adding a value needs a migration, a retired value cannot be forbidden for new rows while kept for old ones, and the labels live nowhere. A specific form of row 17: the domain is held in the schema rather than as data.

Kuidas seda hinnatakse

Flags the deficient case and passes the acceptable one. Deficient: `CHECK (account_status_code IN ('OPN','DOR','CLS'))`; the bank adds `BLK` for blocked accounts and rows are rejected until a release Acceptable: `ref_account_status` with code, label and validity dates, and a foreign key to it; `CHECK` lists only for value sets fixed by definition (an alethic rule, such as Y/N)

Vajalik

  • Puudub