Changes between Version 6 and Version 7 of Normalization

Timestamp:

04/21/26 00:55:37 (11 days ago)

Author:

221296

Comment:

--

Normalization

@@ -89 +89 @@
 == Candidate keys and primary key selection
 === Determining a candidate key
-To determine a candidate key of the universal de-normalized relation, we must identify a minimal set of identifiers whose closure determines all attributes in R.
+To determine a candidate key of the universal de-normalized relation, we identify a minimal set of identifiers whose closure determines all attributes of R.
+
+Because the universal relation combines several independent components of the system (subscriptions, payments, support tickets, course-category assignments, quiz attempts, and certificates), the candidate key must include one identifier from each independent component that is not functionally determined by another component..
 {{{#!comment It is not correct to simply collect all identifiers, because some identifiers are functionally determined by others. For example:
 application_id → clinic_id