Chapter10(pdf) - KFUPM Open Courseware

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Semantics of the Relation Attributes • GUIDELINE 1: Informally, each tuple in a relation should represent one entity or relationship instance. • Attributes of different entities (EMPLOYEEs, DEPARTMENTs, PROJECTs) should not be mixed in the same relation • Only foreign keys should be used to refer to other entities • Entity and relationship attributes should be kept apart as much as possible. • Bottom Line: Design a schema that can be explained easily relation by relation. The semantics of attributes should be easy to interpret. Copyright © 2007 Ramez Elmasri and Shamkant B. Navathe Slide 10- 6
A simplified COMPANY relational database schema Copyright © 2007 Ramez Elmasri and Shamkant B. Navathe Slide 10- 7
Page 1 and 2: Copyright © 2007 Ramez Elmasri and
Page 3 and 4: Chapter Outline • Informal Design
Page 5: Informal Design Guidelines for Rela
Page 9 and 10: Two relation schemas suffering from
Page 11 and 12: EXAMPLE OF AN UPDATE ANOMALY • Co
Page 13 and 14: EXAMPLE OF AN DELETE ANOMALY • Co
Page 15 and 16: Null Values in Tuples • GUIDELINE
Page 17 and 18: Copyright © 2007 Ramez Elmasri and
Page 19 and 20: Functional Dependencies (1) • Fun
Page 21 and 22: Examples of FD constraints • Soci
Page 23 and 24: Normalization of Relations • Norm
Page 25 and 26: Definitions of Keys and Attributes
Page 27 and 28: Normalization into 1NF Copyright ©
Page 29 and 30: Second Normal Form (1) • Uses the
Page 31 and 32: Normalizing into 2NF Copyright © 2
Page 33 and 34: Third Normal Form (2) • A relatio
Page 35 and 36: Normal Forms Defined Informally •
Page 37 and 38: General Normal Form Definitions (2)
Page 39 and 40: BCNF (Boyce-Codd Normal Form) • A
Page 41 and 42: A relation TEACH that is in 3NF but

Chapter10(pdf) - KFUPM Open Courseware

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