'Dependency preservation' diaporamas de présentation

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733 views • 62 slides

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624 views • 62 slides

Functional Dependencies and Normalization

Functional Dependencies and Normalization. Instructor: Mohamed Eltabakh meltabakh@cs.wpi.edu. What to Cover. Functional Dependencies (FDs) Closure of Functional Dependencies Lossy & Lossless Decomposition Normalization. Normalization. First Normal Form (1NF)

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Schema Refinement and Normal Forms

Schema Refinement and Normal Forms. The Evils of Redundancy. Redundancy is at the root of several problems associated with relational schemas: redundant storage, insert/delete/update anomalies

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Schema Refinement and Normal Forms

Schema Refinement and Normal Forms. Instructor: Xintao Wu. The Evils of Redundancy. Redundancy is at the root of several problems associated with relational schemas: redundant storage, insert/delete/update anomalies

571 views • 42 slides

Schema Refinement and Normal Forms

Schema Refinement and Normal Forms. Instructor: Xintao Wu. The Evils of Redundancy. Redundancy is at the root of several problems associated with relational schemas: redundant storage, insert/delete/update anomalies

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Schema Refinement and Normal Forms

Schema Refinement and Normal Forms. Chapter 19. Instructor: Mirsad Hadzikadic. The Evils of Redundancy. Redundancy is at the root of several problems associated with relational schemas: redundant storage, insert/delete/update anomalies

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Functional Dependencies and Normalization

Functional Dependencies and Normalization. Instructor: Mohamed Eltabakh meltabakh@cs.wpi.edu. What to Cover. Functional Dependencies (FDs) Closure of Functional Dependencies Lossy & Lossless Decomposition Normalization. Normalization. First Normal Form (1NF)

928 views • 41 slides

Decomposition, 3NF, BCNF

Decomposition, 3NF, BCNF. Souhad M. Daraghma. Decomposition of a Relation Schema. If a relation is not in a desired normal form, it can be decomposed into multiple relations that each are in that normal form.

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Lecture 7: Schema refinement: Normalisation

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Decomposition

Decomposition. By Timothy Chen CS157A. Goal to Decomposition. Eliminate redundancy by decomposing a relation into several relations in a higher normal form. Example we saw can be eliminated by decomposing the relation schema Movies(title, year, length, filmType, studioName, starName)

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Normalization

Normalization. Dr. Mario Guimaraes. Data Normalization. Primarily a tool to validate and improve a logical design so that it satisfies certain constraints that avoid unnecessary duplication of data.

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Boyce-Codd Normal Form

Boyce-Codd Normal Form. By: Thanh Truong. Boyce-Codd Normal Form. Eliminates all redundancy that can be discovered by functional dependencies But, we can create a normal form more restrictive called 4NF. Definition. A relation schema R is in BCNF with respect to a set F if:

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