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LECTURE 5: Schema Refinement and Normal Forms

LECTURE 5: Schema Refinement and Normal Forms

LECTURE 5: Schema Refinement and Normal Forms. SOME OF THESE SLIDES ARE BASED ON YOUR TEXT BOOK. Anomalies Insertion anomalies Cannot record filmType without starName Deletion anomalies If we delete the last star, we also lose the movie info. Modification (update) anomalies. DECOMPOSITION.

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729 views • 60 slides
Schema Refinement and Normal Forms

Schema Refinement and Normal Forms

Schema Refinement and Normal Forms. Chapter 15. 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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637 views • 47 slides
Review

Review

Review. Exam Su 3:30PM - 6:30PM 2010/12/12 Room C9000. Algebra. Relational Algebra Operations. Basic operations Selection ( ) Selects a subset of rows from relation. Projection ( ) Deletes unwanted columns from relation.

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329 views • 23 slides
Review

Review

Review. Exam Su 3:30PM - 6:30PM 2010/12/12 Room C9000. Algebra. Relational Algebra Operations. Basic operations Selection ( ) Selects a subset of rows from relation. Projection ( ) Deletes unwanted columns from relation.

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293 views • 23 slides
Review

Review

Review. Exam Su 3:30PM - 6:30PM 2010/12/12 Room C9000. Algebra. Relational Algebra Operations. Basic operations Selection ( ) Selects a subset of rows from relation. Projection ( ) Deletes unwanted columns from relation.

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322 views • 23 slides
ICS 321 Fall 2011 Functional Dependencies

ICS 321 Fall 2011 Functional Dependencies

ICS 321 Fall 2011 Functional Dependencies. Asst. Prof. Lipyeow Lim Information & Computer Science Department University of Hawaii at Manoa. Example: Movies1. What are the keys for this relational ? What if you ignore the column starName ? Can starName be a key ?.

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195 views • 12 slides
ICS 321 Fall 2009 Schema Refinement & Normal Forms

ICS 321 Fall 2009 Schema Refinement & Normal Forms

ICS 321 Fall 2009 Schema Refinement & Normal Forms. Asst. Prof. Lipyeow Lim Information & Computer Science Department University of Hawaii at Manoa. The Problem with Redundancy. Hourly_Emps. Suppose hourly wages are determined by rating Redundant storage : (8,10) stored multiple times

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188 views • 8 slides

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