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  1. Prepare
  2. Databases
  3. Database Normalization
  4. Database Normalization #6
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Database Normalization #6

  • myahyamuhaimin
     + 1 comment

    This is my process of identifying the normal forms:

    Tables:
customer(name,addr,MEMBERNO)
movie(DESCRIPTION,director,serialno)
borrow(memberno,DATE,SERIALNO)

Determinants:
memberno -> name,addr
description -> director,serialno
serialno,date -> memberno
serialno -> description
serialno -> director
name,addr -> memberno

CKs:
memberno is CK
description is CK
serialno,date is CK
serialno -> description,director (so serialno is CK)
name,addr is CK

    For 2NF, non-prime attributes must be dependent on CK:

    movie.director: depends on description (is CK) or serialno (is CK)
borrow.memberno: depends on serialno,date (is CK)

    It is in 2NF.

    For 3NF, non-prime attributes must be directly dependent on CK, not transitively dependent:

    movie.director: depends on serialno, then depends on description (is CK)

    It is NOT in 3NF.