database-normalization/vocabulary/database-normalization-vocabulary.yml at main · api-evangelist/database-normalization · GitHub

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name: Database Normalization Vocabulary
description: >-
  Vocabulary of relational normalization concepts including normal forms,
  dependencies, and anomalies.
terms:
  - term: Normalization
    definition: >-
      The systematic decomposition of a relational schema to eliminate
      redundancy and dependency anomalies.
  - term: Denormalization
    definition: >-
      The intentional violation of normal forms to improve read
      performance, typical in analytical schemas.
  - term: Functional Dependency
    definition: >-
      A constraint X -> Y stating that Y is determined by X within a
      relation.
  - term: Multi-Valued Dependency
    definition: >-
      A dependency X ->> Y indicating that for each X there is a set of
      Y values independent of other attributes.
  - term: Join Dependency
    definition: >-
      A dependency expressing that a relation can be losslessly
      decomposed into multiple projections that join back to the
      original.
  - term: Candidate Key
    definition: >-
      A minimal set of attributes that uniquely identifies each tuple
      in a relation.
  - term: Primary Key
    definition: >-
      The candidate key chosen as the principal identifier for a
      relation.
  - term: Superkey
    definition: >-
      Any set of attributes that uniquely identifies tuples, possibly
      with redundant attributes.
  - term: Prime Attribute
    definition: >-
      An attribute that participates in at least one candidate key.
  - term: First Normal Form (1NF)
    definition: >-
      A relation in which every attribute holds atomic values and
      there are no repeating groups.
  - term: Second Normal Form (2NF)
    definition: >-
      A 1NF relation in which every non-prime attribute is fully
      functionally dependent on every candidate key.
  - term: Third Normal Form (3NF)
    definition: >-
      A 2NF relation in which no non-prime attribute transitively
      depends on a candidate key.
  - term: Boyce-Codd Normal Form (BCNF)
    definition: >-
      A relation in which every non-trivial functional dependency has
      a superkey on the left side.
  - term: Fourth Normal Form (4NF)
    definition: >-
      A BCNF relation with no non-trivial multi-valued dependencies
      other than candidate keys.
  - term: Fifth Normal Form (5NF)
    definition: >-
      A 4NF relation with no join dependencies other than those
      implied by candidate keys.
  - term: Sixth Normal Form (6NF)
    definition: >-
      A relation that cannot be further decomposed without loss,
      relevant in temporal database design.
  - term: Domain-Key Normal Form
    definition: >-
      A normal form requiring that every constraint follow from
      domain and key constraints, eliminating all anomalies.
  - term: Update Anomaly
    definition: >-
      Inconsistent data resulting from updating one copy of a
      duplicated value while leaving others unchanged.
  - term: Insertion Anomaly
    definition: >-
      The inability to insert a fact without simultaneously providing
      unrelated information.
  - term: Deletion Anomaly
    definition: >-
      The unintended loss of information caused by deleting a row
      that contains data needed elsewhere.
  - term: Lossless Decomposition
    definition: >-
      A decomposition such that the original relation can be
      reconstructed by joining the projections.
  - term: Dependency Preservation
    definition: >-
      A property of decomposition that preserves the original
      functional dependencies on the decomposed schemas.